JP5228118B2 - Method for producing aluminum alloy conductor - Google Patents

Description

  The present invention relates to an aluminum alloy conductor used as a conductor of an electric wiring body and a manufacturing method thereof.

2. Description of the Related Art Conventionally, a member in which a terminal (connector) made of copper or copper alloy (for example, brass) is mounted on an electric wire including a copper or copper alloy conductor called a wire harness as an electric wiring body of a moving body such as an automobile, a train, or an aircraft However, in light of the recent weight savings of moving bodies, studies are underway to use aluminum or aluminum alloys that are lighter than copper or copper alloys as conductors of electrical wiring bodies.
The specific gravity of aluminum is about 1/3 of copper, and the electrical conductivity of aluminum is about 2/3 of copper (pure aluminum is about 66% IACS when pure copper is used as the standard of 100% IACS). In order to pass the same current as that of a pure copper conductor wire, the cross-sectional area of the pure aluminum conductor wire needs to be about 1.5 times that of the pure copper conductor wire, but the mass is still about half that of copper. Therefore, there is an advantage.
In addition, said% IACS expresses the electrical conductivity when the resistivity 1.7241 × 10 ⁻⁸ Ωm of universal standard annealed copper (International Annealed Copper Standard) is 100% IACS.

There are several problems in using the aluminum as a conductor of an electric wiring body of a moving body, and one of them is improvement of bending fatigue resistance. The reason why the aluminum conductor used for the electric wiring body of the moving body is required to have bending fatigue resistance is that the wire harness attached to the door or the like is repeatedly subjected to bending stress by opening and closing the door. When a metal material such as aluminum is repeatedly applied and removed such as opening and closing of a door even at a low load that does not break at a single load, fatigue failure that breaks at a certain number of repetitions occurs. When the aluminum conductor is used for an opening / closing portion, if the bending fatigue resistance is poor, there is a concern that the conductor may break during use, resulting in a problem of lack of durability and reliability.
Generally, it is said that a material having higher strength has better fatigue characteristics. Therefore, high-strength aluminum wire may be applied, but the wire harness is required to be easy to handle (installation work on the vehicle body) at the time of installation, and generally has an elongation of 10% or more. In many cases, a dull material (annealed material) that can be secured is used.

  Therefore, the aluminum conductor used for the electric wiring body of the moving body is a material having excellent bending fatigue resistance in addition to the strength required for handling and mounting, and the conductivity necessary for flowing a large amount of electricity. Is required.

  For such demanding applications, pure aluminum systems such as power transmission line aluminum alloy wires (JIS A1060 and JIS A1070) cannot sufficiently withstand repeated bending stresses that occur when doors are opened and closed. In addition, although alloyed materials with various additive elements are excellent in strength, they cause a decrease in conductivity due to a solid solution phenomenon of the additive elements in aluminum, and excessive intermetallic compounds are formed in aluminum. Therefore, there is a problem that wire breakage may be caused during wire drawing. Therefore, it is necessary to limit and select additive elements to prevent the decrease in conductivity and workability, and to improve the strength and the bending fatigue resistance.

Typical examples of the aluminum conductor used for the electric wiring body of the moving body include those described in Patent Documents 1 to 3. However, as described below, the inventions described in any of the patent documents have further problems to be solved.
The electric wire conductor described in Patent Document 1 has an excessively high tensile strength, and it may be difficult to perform the attachment work to the vehicle body.
The aluminum conductive wire specifically described in Patent Document 2 is not subjected to finish annealing. Moreover, since Cu is not contained, the elongation is low, and a higher flexibility is required for the mounting work on the vehicle body.
Patent Document 3 discloses an aluminum conductive wire that is lightweight, flexible, and excellent in bendability. However, the demand for improving the characteristics of an electric wiring body of a moving body has only increased, and further improvement in characteristics is desired. Yes.

JP 2008-112620 A JP 2006-19163 A JP 2006-253109 A

This invention makes it a subject to provide the manufacturing method of the aluminum alloy conductor excellent in the bending fatigue-proof characteristic etc.

As a result of various studies, the present inventors control the production process such as the components contained in the aluminum alloy conductor and the casting cooling rate and finish annealing condition of the conductor as satisfying the required bending fatigue resistance. Thus, the inventors have found that the characteristics can be improved by utilizing the effect of the additive element and optimizing the crystal grain size of the conductor, and based on this finding, the present invention has been completed.

That is, the present invention provides the following solutions.
(1) Fe is 0.01 to 0.4 mass%, Cu is 0.3 to 0.5 mass%, Mg is 0.04 to 0.3 mass%, and Si is 0.02 to 0.3 mass%. In addition, it contains 0.001 to 0.01 mass% of Ti and V in combination, and after melting the aluminum alloy component consisting of the remaining Al and inevitable impurities, it is subjected to continuous casting and rolling to obtain a rough bar, which is cold drawn A method for producing an aluminum alloy conductor comprising a step of performing a heat treatment, performing a wire drawing process to obtain a wire, and further performing an annealing heat treatment, wherein the continuous casting rolling is performed at a casting cooling rate. Is performed under the conditions of 1 to 20 ° C./second, and the cold drawing is performed with η = ln (A ₀ / A ₁ ), where A _{0 is} the cross-sectional area of the wire before processing and A ₁ is the cross-sectional area of the wire after processing. The degree of processing expressed by And the heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours, the wire drawing is performed at a workability of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. A method for producing an aluminum alloy conductor, which is performed under conditions of 10 minutes to 6 hours.
(2) Fe 0.01-0.4 mass%, Cu 0.3-0.5 mass%, Mg 0.04-0.3 mass%, Si 0.02-0.3 mass% , Sn, Cd and In, at least one element selected from the group consisting of 0.01 to 0.5 mass% in total amount, further including 0.001 to 0.01 mass% of Ti and V together, the balance After melting the aluminum alloy component consisting of Al and unavoidable impurities, it is continuously cast and rolled into a rough bar, cold drawn to a rough drawn wire, heat treated, drawn to a wire, and further annealed A method for producing an aluminum alloy conductor comprising a step of performing a heat treatment, wherein the continuous casting and rolling is performed at a casting cooling rate of 1 to 20 ° C / second, and the cold drawing is performed before the processing. A wire cross section is A ₀ , where the processed wire rod cross-sectional area is A _{1 and the} degree of processing represented by η = ln (A ₀ / A ₁ ) is 1 to 6 and the heat treatment is performed at a temperature of 300 to 450 ° C. Characterized in that the wire drawing is performed under conditions of a working degree of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours. A method for producing an aluminum alloy conductor.
(3) 0.01-0.4 mass% Fe, 0.3-0.5 mass% Cu, 0.04-0.3 mass% Mg, 0.02-0.3 mass% Si And at least one element selected from the group consisting of Sn, Cd and In in a total amount of 0.01 to 0.5 mass%, further including 0.001 to 0.01 mass% of Ti and V in combination, After melting the aluminum alloy component consisting of 0.001 to 0.1 mass% and the balance Al and inevitable impurities, it is continuously cast and rolled into a rough bar, cold drawn to a rough drawn wire, and heat treatment A method for producing an aluminum alloy conductor comprising a step of performing wire drawing to obtain a wire, and further performing annealing heat treatment, wherein the continuous casting rolling is performed under a condition of a casting cooling rate of 1 to 20 ° C./sec. Done in front In the cold drawing process, the processing degree represented by η = ln (A ₀ / A ₁ ) is 1 or more and 6 or less, where A _{0 is} the cross-sectional area of the wire before processing and A ₁ is the cross-sectional area of the wire after processing. The heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours, the wire drawing is performed at a workability of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450. The manufacturing method of the aluminum alloy conductor characterized by performing on the conditions for 10 minutes-6 hours at ° C.
(4) Fe 0.01-0.4 mass%, Cu 0.3-0.5 mass%, Mg 0.04-0.3 mass%, Si 0.02-0.3 mass% And at least one element selected from the group consisting of Sn, Cd and In in a total amount of 0.01 to 0.5 mass%, further including 0.001 to 0.01 mass% of Ti and V in combination, The mass ratio (W1 /) of the total content (W1) of at least one element selected from the group consisting of Sn, Cd and In and the content (W2) of Zr, including 0.001 to 0.1 mass% W2) is 0.6 to 2.6, and after melting the aluminum alloy component consisting of the balance Al and inevitable impurities, it is continuously cast and rolled to form a rough bar, cold drawn to a rough drawn wire, Perform heat treatment and wire drawing A method for producing an aluminum alloy conductor comprising a step of performing annealing heat treatment, wherein the continuous casting and rolling is performed at a casting cooling rate of 1 to 20 ° C./second, and the cold Drawing is performed under the condition that the degree of processing expressed by η = ln (A ₀ / A ₁ ) is 1 or more and 6 or less, where A _{0 is} the cross-sectional area of the wire before processing and A ₁ is the cross-sectional area of the wire after processing. The heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours, the wire drawing is performed at a workability of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. for 10 hours. A method for producing an aluminum alloy conductor, which is carried out under conditions of minutes to 6 hours.

Hereinafter, the method for producing an aluminum alloy conductor described in the item (1) is referred to as a first embodiment of the present invention.
The method for producing an aluminum alloy conductor described in the items (2) to (4) is referred to as a second embodiment of the present invention.
Here, unless otherwise specified, the present invention is meant to include the first and second embodiments.

The aluminum alloy conductor produced by the production method of the present invention is excellent in strength and conductivity, and is useful as a battery cable, harness or motor conductor mounted on a moving body, and requires excellent bending fatigue resistance. It can be suitably used for doors, trunks, bonnets, and the like.
Furthermore, the aluminum alloy conductor produced by the production method of the present invention is excellent in that the bending fatigue characteristics do not deteriorate even when exposed to high temperatures (for example, 120 ° C.), and is excellent in corrosion resistance.

  The above and other features and advantages of the present invention will become more apparent from the following description, with reference where appropriate to the accompanying drawings.

FIG. 1 is an explanatory diagram of a repeated fracture number test of an example.

First, the first embodiment of the present invention will be described.
The aluminum alloy conductor manufactured in a preferred embodiment of the present invention has Fe of 0.01 to 0.4 mass%, Cu of 0.3 to 0.5 mass%, and Mg of 0.04 to 0.3 mass%. , An aluminum alloy conductor containing 0.02 to 0.3 mass% of Si and further containing 0.001 to 0.01 mass% of Ti and V in combination, the balance being Al and inevitable impurities, It is an aluminum alloy conductor having a crystal grain size of 5 to 25 μm in a vertical cross section in the direction.

  In the present embodiment, the reason why the Fe content is set to 0.01 to 0.4 mass% is mainly to utilize various effects of the Al—Fe-based intermetallic compound. Fe dissolves only 0.05 mass% in aluminum at 655 ° C., and is even less at room temperature. The remainder crystallizes or precipitates as Al-Fe-based second phase particles. This crystallized product or precipitate acts as a crystal grain refining material, and improves strength and bending fatigue resistance. On the other hand, the strength also increases due to the solid solution of Fe. When the Fe content is too small, these effects are insufficient, and when the Fe content is too large, the crystallized material becomes coarse, which causes disconnection in wire drawing and twisting. The desired bending fatigue resistance cannot be obtained. The Fe content is preferably 0.10 to 0.3 mass%, more preferably 0.15 to 0.25 mass%.

  In the present embodiment, the Cu content is set to 0.3 to 0.5 mass% because Cu is solid-solved and strengthened in the aluminum base material to improve the bending fatigue resistance. This is because Al, Fe, Mg, Si and second phase particles are formed to improve the bending fatigue resistance. If the Cu content is too low, the effect is insufficient, and if it is too high, the corrosion resistance and the conductivity are lowered. Furthermore, workability is deteriorated. The Cu content is preferably 0.35 to 0.5 mass%, more preferably 0.4 to 0.5 mass%.

  In this embodiment, the Mg content is set to 0.04 to 0.3 mass% because Mg is solid-solution-strengthened in the aluminum base material, and a part thereof is Al, Fe, Cu, Si. This is because the second phase particles can be formed to improve strength, bending fatigue resistance, and heat resistance. If the Mg content is too low, the effect is insufficient, and if it is too high, the conductivity is lowered. Moreover, when there is too much content of Mg, yield strength will become excess, a moldability and twist property may be degraded, and workability may worsen. The Mg content is preferably 0.08 to 0.3 mass%, more preferably 0.1 to 0.28 mass%.

  In the present embodiment, the Si content is 0.02 to 0.3 mass% because Si is solid-solution-strengthened in the aluminum base material and a part thereof is Al, Fe, Cu, Mg. This is because the second phase particles can be formed to improve strength, bending fatigue resistance, and heat resistance. If the Si content is too small, the effect is insufficient, and if it is too large, the electrical conductivity decreases, the moldability and twistability deteriorate, and the workability deteriorates. In addition, the precipitation of Si alone during the heat treatment process during the production of the wire causes disconnection. The Si content is preferably 0.04 to 0.25 mass%, more preferably 0.04 to 0.20 mass%.

  In this embodiment, both Ti and V act as ingot refining materials during melt casting. If the structure of the ingot is coarse, cracks occur in the wire processing step, which is not industrially desirable. When the contents of Ti and V are too small, the effect is insufficient, and when the contents are too large, the conductivity is greatly reduced, and the effect is saturated. The total content of Ti and V is preferably 0.002 to 0.008 mass%, more preferably 0.003 to 0.006 mass%.

According to the aluminum alloy conductor produced in this embodiment of the present invention, the desired excellent bending fatigue resistance, strength, and conductivity were achieved by strictly defining the crystal grain size in addition to the above components. An aluminum alloy conductor can be obtained.

(Crystal grain size)
In the aluminum alloy conductor is produced in this embodiment of the present invention, the crystal grain size of the drawing direction of the aluminum alloy conductors in vertical section and 5 to 25 [mu] m. The reason for this is that if the thickness is less than 5 μm, a partially unrecrystallized structure remains and the elongation is remarkably reduced. The upper limit is 25 μm, and if a coarse structure exceeding this is formed, the deformation behavior is not uniform. Similarly, the elongation is lowered and the strength is remarkably lowered. The crystal grain size is more preferably 5 to 20 μm.

(Tensile strength)
The tensile strength of the aluminum alloy conductor produced in this embodiment of the present invention is 120 MPa or more. This is because if the tensile strength is less than 120 MPa, the strength is insufficient including handling, and it is difficult to use as an industrial conductor. The tensile strength is preferably 120 to 160 MPa, more preferably 120 to 150 MPa.

(conductivity)
The conductivity of the aluminum alloy conductor produced in this embodiment of the present invention is greater than 57% IACS. This is because when the electrical conductivity is less than 57% IACS, a high current of several tens of A (amperes) flows when used for a power line, so that current loss is severe. The conductivity is preferably 57-62% IACS conductivity, more preferably 58-62% IACS.

(Bending fatigue resistance)
The aluminum alloy conductor produced in this embodiment of the present invention has excellent bending fatigue resistance. In this embodiment, the test is performed with a strain amplitude of ± 0.17% as a reference for the bending fatigue resistance. Bending fatigue resistance varies with strain amplitude. When the strain amplitude is large, the fatigue life is shortened, and when the strain amplitude is small, the fatigue life is lengthened. Since the strain amplitude can be determined by the wire diameter of the wire rod (aluminum alloy conductor) 1 shown in FIG. 1 and the curvature radii of the bending jigs 2 and 3, the wire diameter of the wire rod 1 and the curvature radii of the bending jigs 2 and 3 are arbitrary. It is possible to perform a bending fatigue test by setting to.
Next, assuming that the number of times of opening and closing per day is 10 and the use for 20 years is assumed, the number of times of opening and closing is 73,000 (calculated as 365 days a year). The actually used electric wire is not a single wire but has a stranded wire structure, and since the coating process is performed, the burden on the electric wire conductor becomes a fraction. Table 1 and Table 2 show that the number of repeated fractures of 90000 times or more that can ensure sufficient bending fatigue resistance as an evaluation value for a single wire is desirable. More preferably, it is 100,000 times or more.

Next, a second embodiment of the present invention will be described.
The aluminum alloy conductor produced in another preferred embodiment of the present invention comprises Fe of 0.01 to 0.4 mass%, Cu of 0.3 to 0.5 mass%, and Mg of 0.04 to 0.3 mass. %, Si in an amount of 0.02 to 0.3 mass%, and at least one element selected from the group consisting of Sn, Cd, and In, in a total amount of 0.01 to 0.5 mass%, further containing Ti and V Is an aluminum alloy conductor containing 0.001 to 0.01 mass% of the balance, the balance being Al and unavoidable impurities, and an aluminum alloy conductor having a crystal grain size of 5 to 25 μm in a vertical section in the wire drawing direction.

  The effects of Fe, Cu, Mg, Si, Ti, and V, the reasons for limiting the range of the addition amount, and the preferable range of the addition amount are as described above.

In order to further improve the bending fatigue resistance as compared with the alloys described above, it is preferable to suppress the formation of second phase particles containing two or more of Al, Fe, Cu, Mg, and Si as components.
By the way, Sn, Cd, and In have a function of capturing vacancies in the aluminum alloy, that is, a function of suppressing or delaying a diffusion action that proceeds with the vacancies. Generation of second phase particles containing two or more of Fe, Cu, Mg, and Si as components is suppressed. As a result, the bending fatigue resistance can be further improved by adding at least one element selected from the group consisting of Sn, Cd and In.
The content of at least one element selected from the group consisting of Sn, Cd, and In is 0.01 to 0.5 mass% in total. If it is less than 0.01 mass%, the effect of inhibiting the generation of second phase particles If the amount exceeds 0.5 mass%, the effect of inhibiting the formation is lost and conversely the generation of the second phase particles is accelerated, and the elongation decreases. If the total amount is too large, cracks occur during wire drawing. This is because it tends to occur and industrial production cannot be realized.

  However, the effect of suppressing the formation of second phase particles by the addition of at least one element selected from the group consisting of Sn, Cd and In is remarkable at a low temperature of 100 ° C. or lower, but at a high temperature exceeding 100 ° C. The higher the temperature is, the less effective the suppression is and the generation of precipitated particles may occur. Therefore, the phenomenon that the precipitation suppressing effect disappears can be canceled by further adding Zr. Zr is added together with at least one element selected from the group consisting of Sn, Cd, and In, so that even at a high temperature exceeding 100 ° C., Zr contains two or more of Al, Fe, Cu, Mg, and Si as components. It has the effect of suppressing the formation of two-phase particles. If the amount of Zr added is 0.001 to 0.1 mass%, the effect is insufficient if it is less than 0.001 mass%, and if it exceeds 0.1 mass%, Al-Zr-based second phase particles. This is because the generation amount of is increased to reduce the bending fatigue resistance.

  In the mass ratio (W1 / W2) of the total content (W1) of at least one element selected from the group consisting of Sn, Cd, and In and the content (W2) of Zr (W1 / W2), a more preferable range is 0.6. ~ 2.6. Within this range, even at a high temperature exceeding 100 ° C., it has the effect of more effectively suppressing the generation of second phase particles containing two or more of Al, Fe, Cu, Mg, and Si as components.

According to the aluminum alloy conductor produced in this embodiment of the present invention, the desired excellent bending fatigue resistance, strength, and conductivity were achieved by strictly defining the crystal grain size in addition to the above components. An aluminum alloy conductor can be obtained.

(Crystal grain size)
In the aluminum alloy conductor is produced in this embodiment of the present invention, the crystal grain size of the drawing direction of the aluminum alloy conductors in vertical section and 5 to 25 [mu] m. The reason for this is that if the thickness is less than 5 μm, a partially unrecrystallized structure remains and the elongation is remarkably reduced. The upper limit is 25 μm, and if a coarse structure exceeding this is formed, the deformation behavior is not uniform. Similarly, the elongation is lowered and the strength is remarkably lowered. The crystal grain size is more preferably 5 to 20 μm.

(Tensile strength)
The tensile strength of the aluminum alloy conductor produced in this embodiment of the present invention is 120 MPa or more. This is because if the tensile strength is less than 120 MPa, the strength is insufficient including handling, and it is difficult to use as an industrial conductor. The tensile strength is preferably 120 to 160 MPa, more preferably 120 to 150 MPa.

(conductivity)
The conductivity of the aluminum alloy conductor produced in this embodiment of the invention is 52% IACS or higher. Originally, when the electrical conductivity is less than 57% IACS, a high current of several tens of A (amperes) flows when used for a power line, and there is a concern that current loss becomes severe. is there. However, for example, when applied to a communication line such as a battery cable or a wire harness in a moving body, the range is not limited to 57% IACS or more, and may be 52% IACS or more.

(Bending fatigue resistance)
The aluminum alloy conductor produced in this embodiment of the present invention has excellent bending fatigue resistance. In this embodiment, the test is performed with a strain amplitude of ± 0.17% as a reference for the bending fatigue resistance. Bending fatigue resistance varies with strain amplitude. When the strain amplitude is large, the fatigue life is shortened, and when the strain amplitude is small, the fatigue life is lengthened. Since the strain amplitude can be determined by the wire diameter of the wire rod (aluminum alloy conductor) 1 shown in FIG. 1 and the curvature radii of the bending jigs 2 and 3, the wire diameter of the wire rod 1 and the curvature radii of the bending jigs 2 and 3 are arbitrary. It is possible to perform a bending fatigue test by setting to.
Next, assuming that the number of times of opening and closing per day is 10 and the use for 20 years is assumed, the number of times of opening and closing is 73,000 (calculated as 365 days a year). The actually used electric wire is not a single wire but has a stranded wire structure, and since the coating process is performed, the burden on the electric wire conductor becomes a fraction. Table 3 shows that the number of repeated fractures of 80000 times or more that can ensure sufficient bending fatigue resistance as an evaluation value for a single wire is desirable. More preferably, it is 100,000 times or more, More preferably, it is 150,000 times or more. In automobile applications, electric wires may be exposed to high temperatures under harsh usage environments. In general, when 10 years of use is assumed, an accelerated test is applied in which exposure is performed at a high temperature of 120 ° C. for 120 hours. Therefore, even after leaving at 120 ° C. for 120 hours, the number of repeated fractures is preferably 80000 times or more, and more preferably 90000 times or more.

(Production method)
The manufacturing method of the aluminum alloy conductor of the 1st and 2nd embodiment of this invention is demonstrated.
The aluminum alloy conductor manufactured by the manufacturing method of the first and second embodiments of the present invention includes [1] melting, [2] casting, [3] hot or cold processing (such as groove roll processing), [ 4) Wire drawing, [5] Heat treatment (intermediate annealing), [6] Wire drawing, [7] Heat treatment (finish annealing) can be produced under predetermined production conditions .

  To obtain the aluminum alloy composition of the present invention, first, at least one element selected from the group consisting of Fe, Cu, Mg, Si, Ti, V, and Al, or further, Sn, Cd, and In. Each alloy component combined with each other, or each alloy component combined with any one of these alloy components and Zr is melted in an amount so as to obtain a desired concentration.

  Next, rolling is performed while continuously casting the molten metal in a water-cooled mold using a Properti-type continuous casting and rolling machine in which a casting wheel and a belt are combined to obtain a rough bar having a diameter of about 10 mm. From casting to processing of a wire of about φ10 mm can be carried out continuously, and further, steps such as a reheating step can be omitted, so that productivity can be greatly improved. The casting cooling rate at this time is 1 to 20 ° C./second.

Next, the surface is peeled to 9 to 9.5 mmφ, which is drawn to obtain a rough drawn wire. Here, when the wire cross-sectional area before wire drawing is A ₀ , and the wire cross-sectional area after wire drawing is A ₁ , the degree of work represented by η = ln (A ₀ / A ₁ ) is 1 or more and 6 It is as follows. If the degree of work is too small, the recrystallized grains become coarse during the heat treatment in the next step, and the strength and elongation are remarkably reduced, causing disconnection. If it is too large, the wire drawing process becomes difficult, and there is a problem in terms of quality such as disconnection during the wire drawing process. Although the surface is cleaned by carrying out the peeling of the surface, it may not be carried out.

  Cold-drawn rough drawn wire is subjected to intermediate annealing using a batch annealing furnace. The temperature of the intermediate annealing is 300 to 450 ° C. If it is lower than 300 ° C., unrecrystallized grains remain and cause breakage during the subsequent wire drawing. Moreover, when it exceeds 450 degreeC, a coarse recrystallized grain will be formed, tensile strength and elongation will fall remarkably, and also in this case, there is a problem in terms of quality, such as disconnection during wire drawing. The time is 10 minutes to 6 hours. If it is less than 10 minutes, unrecrystallized grains remain and cause wire breakage during subsequent wire drawing. On the other hand, if it exceeds 6 hours, coarse recrystallized grains are formed depending on the heat treatment temperature, the tensile strength and the elongation are remarkably lowered, and there is a risk of disconnection during the wire drawing. From the viewpoint of productivity, it is not good if it exceeds 6 hours. The conditions for the intermediate annealing are preferably 300 to 450 ° C. and 30 minutes to 4 hours.

  Further, wire drawing is performed to obtain a wire. At this time, the degree of processing is 1 or more and 6 or less for the above-mentioned reason.

A cold-drawn wire having a predetermined wire diameter is subjected to finish annealing in a batch annealing furnace to obtain an aluminum alloy conductor. The temperature of the finish annealing is 300 to 450 ° C. This is because when the temperature is lower than 300 ° C., non-recrystallized grains remain and sufficient flexibility cannot be secured. Moreover, when it exceeds 450 degreeC, a coarse recrystallized grain will be formed and tensile strength and elongation will fall remarkably. The time is 10 minutes to 6 hours. If it is less than 10 minutes, unrecrystallized grains remain and sufficient flexibility cannot be secured. Further, if it exceeds 6 hours, coarse recrystallized grains are formed depending on the heat treatment temperature, and the tensile strength and elongation are remarkably lowered. From the viewpoint of productivity, it is not good if it exceeds 6 hours. The conditions for finish annealing are preferably 300 to 450 ° C. and 30 minutes to 4 hours.
In addition to batch-type annealing, finish annealing includes, for example, electrical annealing in which electricity is applied to the conductor and annealing with Joule heat, and running annealing in which the wire continuously passes through an annealing furnace maintained at a high temperature. Alternatively, induction heating in which the wire is continuously passed through the magnetic field and annealed may be used. In this case, since the heat treatment is generally performed at a high temperature for a short time, the conditions for finish annealing are different from those for batch annealing.

As described above in detail, the aluminum alloy conductor produced in these embodiments of the present invention, which has been appropriately heat-treated, has a recrystallized structure in addition to having the predetermined crystal grain size. The recrystallized structure is a structure state composed of crystal grains with few lattice defects such as dislocations introduced by plastic working. By having a recrystallized structure, tensile elongation at break and electrical conductivity are recovered, and sufficient flexibility can be obtained.

  The invention is explained in more detail on the basis of the following examples. In addition, this invention is not limited to the Example shown below.

Example No. 1-24, Comparative Example No. 1-12
(First embodiment of the present invention, that is, examples and comparative examples of the invention described in the above item (1) )
As shown in Table 1 (Examples) and Table 2 (Comparative Examples) described later, Fe, Cu, Mg, Si, Ti, V, and Al were used at predetermined ratios (mass%) to form alloys. Here, about Al, it was JIS-H4040 alloy number 1070 and content of an inevitable impurity shall not exceed the value of Table 1 and Table 2. Comparative Example No. 1 (pure Al), Comparative Example No. 2, Comparative Example No. For No. 8, high-purity aluminum (Four Nine (4N)) was used as Al.
This alloy was rolled using a Properti type continuous casting and rolling machine while continuously casting it in a mold in which the molten metal was cooled with water to obtain a rough bar having a diameter of about 10 mm. The casting cooling rate at this time was 1 to 20 ° C./second.
Next, the surface was peeled to 9 to 9.5 mmφ, which was drawn to obtain a 2.6 mmφ rough wire. Next, as shown in Table 1 and Table 2, this cold-drawn workpiece is subjected to intermediate annealing at a temperature of 300 to 450 ° C. for 0.5 to 4 hours, and further drawn to obtain a wire diameter of 0. A wire rod of 31 mmφ was used.
Finally, as final annealing, batch-type heat treatment was performed as finishing annealing at a temperature of 300 to 450 ° C. (including 250 ° C. and 500 ° C. in the comparative example) for 0.5 to 4 hours to obtain an aluminum alloy conductor.

Comparative Example No. 13
As shown in Table 2 below, Fe, Cu, Mg, and Al were dissolved in a conventional manner using a predetermined amount ratio (mass%), and cast into a 25.4 mm square mold to obtain an ingot. . Next, the ingot was held at 400 ° C. for 1 hour, and hot rolled with a groove roll to process into a rough drawn wire having a wire diameter of 9.5 mm.
Next, after drawing the rough drawn wire to a wire diameter of 0.9 mm, heat-treating at 350 ° C. for 2 hours and quenching, and then continuing the wire drawing to an aluminum alloy wire having a wire diameter of 0.32 mm Was made.
Finally, the manufactured aluminum alloy strand having a wire diameter of 0.32 mm was subjected to a heat treatment held at 350 ° C. for 2 hours and gradually cooled.

Comparative Example No. 14
As shown in Table 2 below, Fe, Mg, Si and Al are melted by a conventional method using a predetermined amount ratio (mass%) and processed into a rough drawn wire having a wire diameter of 9.5 mm by a continuous casting and rolling method. did.
Next, after drawing the rough drawn wire to a wire diameter of 2.6 mm, a heat treatment was held at 350 ° C. for 2 hours so that the tensile strength after heat treatment was 150 MPa or less, and the wire drawing was continued. An aluminum alloy strand having a diameter of 0.32 mm was produced.

Comparative Example No. 15
As shown in Table 2 below, a cast bar was manufactured by casting an alloy melt prepared by melting Fe, Mg, Si, and Al at a predetermined ratio (mass%) using a continuous casting machine. Next, a φ9.5 mm wire rod was produced by a hot rolling mill, and the obtained wire rod was subjected to cold wire drawing to produce a φ0.26 mm wire element. Subsequently, seven wire strands were twisted to form a stranded wire. Thereafter, solution treatment, cooling, and aging heat treatment were performed to obtain a wire conductor. The solution treatment temperature at this time is 550 ° C., the tempering temperature in aging heat treatment is 170 ° C., and the tempering time is 12 hours. Each characteristic shown in Table 2 was evaluated by separating the stranded wire into one strand.

  Each characteristic was measured by the following method about the produced aluminum alloy conductor of each Example and a comparative example. The results are shown in Tables 1 and 2 below.

(A) Crystal grain size (GS)
The cross section of the specimen cut out perpendicular to the wire drawing direction was filled with resin, and after mechanical polishing, electrolytic polishing was performed. The electrolytic polishing conditions are: an ethanol solution containing 20% perchloric acid as the polishing liquid, a liquid temperature of 0 to 5 ° C., a voltage of 10 V, a current of 10 mA, and a time of 30 to 60 seconds. Next, in order to obtain crystal grain contrast, anodic finishing was performed using 2% borohydrofluoric acid under the conditions of a voltage of 20 V, a current of 20 mA, and a time of 2 to 3 minutes. This structure was photographed with an optical microscope of 200 to 400 times, and the particle size was measured by the crossing method. Specifically, a straight line was drawn on the photographed image, and the number of intersections of the straight line length and the grain boundary was measured to obtain the average particle diameter. The particle size was calculated by changing the length and number of straight lines so that 50 to 100 particles could be counted.
(B) Tensile strength (TS) and flexibility (tensile elongation at break, El)
Three each were tested according to JIS Z 2241 and the average value was determined. The flexibility was evaluated using the tensile elongation at break, and the tensile elongation at break was 10% or more.
(C) Conductivity (EC)
Three specific resistances were measured using a four-terminal method in a constant temperature bath holding a 300 mm long test piece at 20 ° C. (± 0.5 ° C.), and the average conductivity was calculated. The distance between the terminals was 200 mm.
(D) Number of repeated fractures Using a double-bending bending fatigue testing machine manufactured by Fujii Seiki Co., Ltd. (currently Fujii Co., Ltd.), a jig that gives a bending strain of ± 0.17% to the wire (aluminum alloy conductor) is used. Then, the number of repeated fractures was measured by repeatedly bending. The number of repeated ruptures was measured four by four and the average value was determined. As shown in the explanatory view of FIG. 1, the wire 1 was inserted with a gap of 1 mm between the bending jigs 2 and 3, and repeatedly moved in such a manner as to be along the jigs 2 and 3. One end of the wire was fixed to a holding jig 5 so that it could be bent repeatedly, and a weight 4 of about 10 g was hung from the other end. Since the holding jig 5 moves during the test, the wire 1 fixed to the holding jig 5 also moves and can be bent repeatedly. The repetition is performed under the condition of 1.5 Hz (1.5 reciprocations per second), and when the wire specimen 1 breaks, the weight 4 falls and stops counting.

As is apparent from Tables 1 and 2, Comparative Example No. made of pure Al. The conductor No. 1 has a large crystal grain size, low tensile strength, and inferior bending fatigue resistance, so the number of repeated fractures is small. Comparative Example No. In the case of 2 to 10 aluminum alloy conductors, the alloy composition is outside the specified range of the present invention. The number of repeated fractures is insufficient in aluminum alloy conductors of 2 to 4, 6, and 8 to 10. Comparative Example No. The 5, 7, 9, 10 aluminum alloy conductors have insufficient electrical conductivity. Further, the aluminum alloy conductors of Comparative Examples 2, 4, and 6 have insufficient tensile strength. Comparative Example No. The aluminum alloy conductors Nos. 11 and 12 are examples in which the production conditions are outside the specified range of the present invention. The 12 aluminum alloy conductors also lack the tensile strength and the number of repeated breaks. Comparative Example No. The aluminum alloy conductor 13 is a reproduction of Example 2 of JP-A-2006-253109, but the number of repeated fractures is insufficient. Comparative Example No. The aluminum alloy conductor No. 14 is a reproduction of Example 6 of JP-A-2006-19163, but the crystal grain size of the present invention cannot be obtained and the tensile elongation at break is insufficient. Comparative Example No. The aluminum alloy conductor No. 15 is a reproduction of Example 3 of JP-A-2008-112620, but the crystal grain size of the present invention cannot be obtained, and the tensile elongation at break and the electrical conductivity are insufficient.
On the other hand, Example No. The aluminum alloy conductors 1 to 24 were excellent in bending fatigue resistance, tensile characteristics, and conductivity, and were aluminum alloy conductors suitable for applications such as wire harnesses used for doors, trunks, bonnets and the like of moving vehicle bodies.

Example No. 101-120, Comparative Example No. 121-127
(Second embodiment of the present invention, that is, examples and comparative examples of the invention described in the above items (2) to (4) )
As shown in Tables 3 and 4 to be described later, Fe, Cu, Mg, Si, Ti, V, Sn, Cd, In, Zr, and Al were used in a predetermined amount ratio (mass%), and the above-described examples were used. In the same manner, an aluminum alloy conductor was prepared.
Each characteristic was measured about the produced aluminum alloy conductor of each Example and the comparative example similarly to the above-mentioned Example. Further, the number of repeated breaks was also measured for the characteristics after being left at 120 ° C. for 120 hours. The results are shown in Tables 3 and 4. In addition, the aluminum alloy conductor Nos. About 1-20, the frequency | count of repeated fracture | rupture after standing at 120 degreeC for 120 hours was measured. The results are shown in Table 5.

From Table 3, No. In the aluminum alloy conductor containing Sn, Cd, In, and Zr of 101 to 120, the number of repeated breaks was slightly lower than that of the aluminum alloy conductor not containing Sn, Cd, In, and Zr shown in Table 1. . However, no. In the 101-114 aluminum alloy conductors, the number of repeated breaks after leaving at 120 ° C. did not decrease much as compared with the case where it was not left to heat, and maintained high bending resistance. Table 5 shows the number of repeated breaks of the wire materials listed in Table 1 after being left at 120 ° C., and it can be seen that the decrease due to the heating is significant.
No. The 115 to 120 aluminum alloy conductors had the result that the number of repeated breaks on the contrary was improved when left at 120 ° C.
From the above, no. It has been found that an aluminum alloy conductor containing 101 to 120 Sn, Cd, In, and Zr does not significantly degrade the number of repeated breaks, or conversely, even after being left at 120 ° C.
On the other hand, no. In the aluminum alloy conductors 121 to 123 and the aluminum alloy conductors to which Sn, Cd, In, and Zr in Table 5 were not added, the number of repeated breaks after leaving at 120 ° C. was significantly reduced compared to that before leaving at 120 ° C. for heating. It was a result. In addition, when Sn, Cd, In, and Zr are added excessively (Table 4, Nos. 124 to 126), the number of repeated breaks after leaving at 120 ° C. is greatly reduced as compared with the case of not leaving them. Moreover, the fall of elongation and the fall of electrical conductivity were large. In addition, when excess Zr was added (Table 4, No. 127), the number of repeated fractures was low without being left at 120 ° C.

  While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

  This application claims the priority based on Japanese Patent Application No. 2010-163416 for which it applied for a patent in Japan on July 20, 2010, and this is referred to here for the contents of this description. Capture as part.

1 Test piece (wire, aluminum alloy conductor)
2, 3 Bending jig 4 Weight 5 Holding jig

Claims (4)

Fe contains 0.01-0.4 mass%, Cu 0.3-0.5 mass%, Mg 0.04-0.3 mass%, Si 0.02-0.3 mass% In addition, Ti and V are combined to contain 0.001 to 0.01 mass%, and the aluminum alloy component consisting of the remaining Al and inevitable impurities is dissolved, and then continuously cast and rolled to obtain a rough bar, which is then rough drawn by cold drawing. A method for producing an aluminum alloy conductor comprising a step of performing a heat treatment, performing a wire drawing process to obtain a wire, and further performing an annealing heat treatment, wherein the continuous casting and rolling has a casting cooling rate of 1 to The cold drawing is performed under the condition of 20 ° C./second, and is expressed by η = ln (A ₀ / A ₁ ), where A _{0 is} the cross-sectional area of the wire before the processing, and A ₁ is the cross-sectional area of the wire after the processing. The degree of processing is 1 to 6 The heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours, the wire drawing is performed at a workability of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes. The manufacturing method of the aluminum alloy conductor characterized by performing on the conditions for-6 hours. 0.01 to 0.4 mass% Fe, 0.3 to 0.5 mass% Cu, 0.04 to 0.3 mass% Mg, 0.02 to 0.3 mass% Si, Sn, It contains at least one element selected from the group consisting of Cd and In in a total amount of 0.01 to 0.5 mass%, and further contains 0.001 to 0.01 mass% of Ti and V, with the balance being inevitable with Al. After melting the aluminum alloy component consisting of impurities, continuous casting and rolling to make a rough bar, cold drawing to rough drawing wire, heat treatment, wire drawing to wire, and further annealing heat treatment A process for producing an aluminum alloy conductor comprising a step, wherein the continuous casting and rolling is performed under a condition of a casting cooling rate of 1 to 20 ° C./second, and the cold drawing is performed before the processing. the _a 0, The wire cross-sectional area after factory as _{A 1,} eta = ln working ratio represented by _(A 0 / A ₁₎ is performed in 1 to 6 conditions, the heat treatment, 10 minutes at a temperature 300 to 450 ° C. ~ The aluminum is characterized in that it is performed under conditions of 6 hours, the wire drawing is performed under conditions of a working degree of 1 or more and 6 or less, and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours. A method for producing an alloy conductor. 0.01 to 0.4 mass% Fe, 0.3 to 0.5 mass% Cu, 0.04 to 0.3 mass% Mg, 0.02 to 0.3 mass% Si, Sn, At least one element selected from the group consisting of Cd and In is contained in a total amount of 0.01 to 0.5 mass%, and Ti and V are combined in an amount of 0.001 to 0.01 mass%. After melting the aluminum alloy component comprising 001 to 0.1 mass% and the balance Al and unavoidable impurities, it is continuously cast and rolled into a rough bar, cold drawn into a rough drawn wire, heat treated, stretched A method for producing an aluminum alloy conductor comprising a step of performing wire processing to obtain a wire, and further performing an annealing heat treatment, wherein the continuous casting rolling is performed under a condition of a casting cooling rate of 1 to 20 ° C / second, Cold The pulling process, the wire cross-sectional area before processing A _0, the wire cross-sectional area after working as A _1, eta = working ratio expressed by ln _(A 0 / A ₁₎ is performed in 1 to 6 conditions The heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours, the wire drawing is performed at a workability of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. for 10 hours. A method for producing an aluminum alloy conductor, which is carried out under conditions of minutes to 6 hours. 0.01 to 0.4 mass% Fe, 0.3 to 0.5 mass% Cu, 0.04 to 0.3 mass% Mg, 0.02 to 0.3 mass% Si, Sn, At least one element selected from the group consisting of Cd and In is contained in a total amount of 0.01 to 0.5 mass%, and Ti and V are combined in an amount of 0.001 to 0.01 mass%. The mass ratio (W1 / W2) of the total content (W1) of at least one element selected from the group consisting of Sn, Cd and In and the content (W2) of Zr including 001 to 0.1 mass% 0.6 to 2.6, after melting the aluminum alloy component consisting of the remaining Al and inevitable impurities, continuous casting and rolling to obtain a rough bar, cold drawn to a rough drawn wire, and heat treatment Wire drawing, wire drawing And a method of manufacturing an aluminum alloy conductor further comprising a step of performing annealing heat treatment, wherein the continuous casting and rolling is performed under a condition of a casting cooling rate of 1 to 20 ° C./second, and the cold drawing process is performed. The degree of work represented by η = ln (A ₀ / A ₁ ) is 1 or more and 6 or less, where A _{0 is} the cross-sectional area of the wire before processing, and A ₁ is the cross-sectional area of the wire after processing. Is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 hours, the wire drawing is performed at a workability of 1 to 6 and the annealing heat treatment is performed at a temperature of 300 to 450 ° C. for 10 minutes to 6 The manufacturing method of the aluminum alloy conductor characterized by performing on the conditions of time.

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