JP3530181B1 - Composite wire for wire harness and manufacturing method thereof - Google Patents

Abstract

The present invention provides a composite wire for a wire harness which has excellent conductive performance and strength and can further improve corrosion resistance. SOLUTION: In mass%, C: 0.01 to 0.25, N: 0.01 to 0.25,
Mn: 0.5 to 4.0, Cr: 16 to 20, Ni: 8.0 to 14.0, the balance being Fe and impurities in a stainless steel wire consisting of 0.15 mass% ≦ C + N ≦ 0.30 mass% And the first strand that satisfies
It is formed by twisting a second wire selected from at least one of a copper wire, a copper alloy wire, an aluminum wire and an aluminum alloy wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire harness composite wire suitable for a wire harness provided in an automobile and a method for manufacturing the same. In particular, the present invention relates to a composite wire for a wire harness capable of improving corrosion resistance while having excellent conductive performance and strength, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In automobiles, a wire harness (internal wiring) is usually provided in the vehicle, and the wire harness is used for power supply, communication, sensing, etc. to electric components in the vehicle. The wire harness is mainly composed of an automobile electric wire, a protective material, and connectors, and a metal wire containing copper as a main component has been conventionally used as a conductor of the automobile electric wire.

In recent years, the weight of vehicle parts has been reduced due to the demand for low fuel consumption of automobiles, and wire harnesses are no exception. In addition, due to the need for resource saving and recycling, it is required to reduce the amount of copper used.

The characteristics required for electric wires can be roughly classified into two. One is the conductor resistance and the other is the wire strength. Copper, which is often used for the conductor of the above-mentioned electric wire for automobiles, is a metal material having a very low electric resistance,
Even if a wire having a relatively small wire diameter is used, sufficient electric conductivity can be obtained as an electric wire, but in order to maintain the strength required for the electric wire, it is necessary to increase the wire diameter to some extent. Therefore, it is required to reduce the amount of copper used while maintaining the wire strength.

On the other hand, as a conductor of an electric wire, there is a conductor having a copper layer on the outer circumference of a stainless steel wire (see, for example, Patent Documents 1 and 2). There is also a twisted wire formed by twisting a stainless steel wire and a copper wire (see, for example, Patent Documents 3 and 4).

[0006]

[Patent Document 1] Japanese Patent Laid-Open No. 1-283707

[Patent Document 2] Japanese Patent Publication No. 7-31939

[Patent Document 3] Japanese Patent Publication No. 63-23015

[Patent Document 4] Japanese Patent Laid-Open No. 1-225006

[0007]

In order to reduce the amount of copper used while maintaining the strength of the electric wire in the conductor of the above-mentioned electric wire for automobiles, a metal wire other than copper or a metal wire made of a copper alloy is used instead of copper. Can be used. Examples of metals other than copper include lightweight aluminum. However, since aluminum has lower toughness than copper, it has a problem that it is easily damaged when crimping a terminal to an electric wire. Therefore, it is possible to increase the toughness by heat-treating aluminum or forming an aluminum alloy to prevent damage during crimping, but in this case, there is a possibility that the strength will be insufficient and it is not always a sufficient solution. It is not always the case. Further, when a copper alloy is used, the strength cannot be expected to be greatly improved in the first place, and therefore, considering the strength required for the electric wire, there is a limit in reducing the amount of copper used and reducing the weight.

Therefore, it is conceivable to combine a plurality of kinds of metals instead of forming the conductor with only a single kind of metal as described above. For example, the conductors described in Patent Documents 1 and 2 are excellent in low conductor resistance by forming a copper layer having a cross-sectional area ratio of 5 to 70% on the outer circumference of a stainless steel wire by a plating method or a clad method. It has wire strength and excellent toughness. However, these conductors require that a copper layer be formed after the stainless steel wire is manufactured, which not only takes time to manufacture, but also when such a copper layer is formed by an existing plating method or clad method. , The cost could be very high.

On the other hand, the twisted wires described in Patent Documents 3 and 4 are
By twisting a metal wire such as copper and a stainless steel wire, which is generally excellent in strength, it is possible to manufacture at a relatively low cost and to increase the strength of the electric wire. However, Patent Documents 3 and 4 do not mention a configuration for further improving the corrosion resistance. For example, the twisted wire described in Patent Document 3 is SUS as described in Examples of Patent Document 3.
By using ferritic stainless steel such as 430 and annealed copper for electrical use, it has excellent strength and corrosion resistance that can be used as a messenger wire in coastal areas. However, since the conductor of the electric wire for automobiles is usually exposed to a corrosive atmosphere under the condition where a current flows frequently, it is in a more severe situation than the messenger wire that does not carry a current frequently, and the ferritic stainless steel or A conductor using annealed copper for electrical use cannot satisfy sufficient corrosion resistance as a conductor of an electric wire for an automobile. The stranded wire described in Patent Document 4 is a conductor for a wire harness, but there is a demand for further improvement in corrosion resistance against battery corrosion.

Therefore, it is conceivable to use austenitic stainless steel such as SUS304, which generally has high corrosion resistance, as the stainless steel wire described in Patent Documents 1 to 4. However, even with the above stainless steel, the risk of reducing the corrosion resistance by inducing a martensite phase by performing wire processing such as wire drawing and twisting to improve the strength such as tensile strength and breaking load There is a nature. Further, SUS316 and SUS310 are known as austenitic stainless steels having higher corrosion resistance, but these stainless steels are not as strong as SUS304. Therefore, when the stainless steel wire made of SUS316 or SUS310 is used instead of reducing the copper wire while having the conductivity required for the wire harness, it is difficult to improve the strength.

[0011] Therefore, a main object of the present invention is to provide a composite wire for a wire harness, which has excellent conductivity and strength and can further improve the corrosion resistance.

Another object of the present invention is to provide a method for manufacturing a composite wire for a wire harness, which is lower in cost, lighter in weight, and capable of reducing the amount of copper used.

[0013]

The present invention achieves the above object by twisting a wire of copper or the like and a wire of stainless steel having a specific composition. That is, the composite wire for a wire harness of the present invention has a mass% of C: 0.01 to 0.25, N: 0.01 to 0.
Contains 25, Mn: 0.5 to 4.0, Cr: 16 to 20, Ni: 8.0 to 14.0,
A stainless steel wire with the balance being Fe and impurities, the first element wire having a C and N content of 0.15% by mass ≤ C + N ≤ 0.30% by mass, copper wire, copper alloy wire, aluminum wire and aluminum alloy wire And a second strand selected from at least one of the above.

In the present invention, first, by using a first element wire made of stainless steel and a second element wire made of copper or the like in combination, the electric wire strength is maintained while having sufficient conductive performance, and the copper wire is made of copper. Reduce the amount used to reduce weight. Further, by constructing these strands by twisting them, manufacturing at a lower cost is realized. Further, as compared with a conductor made of a single metal such as aluminum alone, a decrease in toughness can be reduced by using different kinds of metals. And, in particular, as the composition of the stainless steel wire which is the first element wire, in particular, C and N which are austenite forming elements.
Is added to improve the stability of the austenite phase, suppress the martensite phase induced by wire working such as wire drawing and twisting, and improve the corrosion resistance. In addition, due to the effect of the solid solution strengthening of C and N, the tensile strength can be increased as compared with the conventional austenitic stainless steel wire, and the strength can be improved. Hereinafter, the present invention will be described in more detail.

<First strand> In particular, the stainless steel wire used in the present invention contains C and N, which are interstitial solid solution elements, in a larger amount than in ordinary austenitic stainless steel. C, N
The interstitial solid solution elements such as the austenite phase that is the base
When included in the (γ phase), while stabilizing the γ phase,
It has the effect of solid solution strengthening to generate and strengthen strain in the crystal lattice, and the effect of fixing dislocations in the metal structure (Cottrell atmosphere). Due to these effects, even if wire processing such as wire drawing and twisting is performed to improve strength,
It is possible to achieve both excellent corrosion resistance equal to or higher than SUS316, and high mechanical properties. In order to obtain such an excellent effect, in the present invention, the total content of C and N in the stainless steel wire (C + N amount) is 0.15 mass% or more 0.3
The amount is 0% by mass. When the amount of C + N is less than 0.15% by mass, solid solution strengthening and dislocation fixing are insufficient, and it is difficult to improve strength and corrosion resistance. If the amount of C + N exceeds 0.30% by mass, the amount of carbides and nitrides generated during casting becomes large, making it difficult to perform subsequent wire drawing and other processing, and easily causing blowholes. Become. A more preferable C + N amount is 0.20 mass% or more and 0.30 mass% or less.

Further, in order to make the electric wire for automobiles thinner and lighter, it is necessary to appropriately adjust the tensile strength and toughness of the stainless steel wire. As a result of examination by the present inventors, it was found that the stainless steel wire manufactured under the following conditions can have appropriate strength and toughness as a conductor of an electric wire for automobiles. That is, the stainless steel wire used in the present invention, the stainless steel material is drawn at a surface reduction rate of 5% or more and 98% or less to adjust to a predetermined wire diameter, and then the temperature
Those that have been heat-treated at a temperature of 950 ° C or higher and 1150 ° C or lower and a holding time of 0.5 seconds or longer and 60 seconds or shorter are suitable. More preferably, the area reduction rate:
5% or more and 70% or less, heat treatment temperature: 1000 ° C or more and 1100 ° C or less, holding time: 0.5 seconds or more and 20 seconds or less. Further, in the above temperature range, it is preferable to make the holding time longer when the heat treatment temperature is lower and shorten the holding time when the heat treatment temperature is higher. When the heat treatment temperature is lower than 950 ° C, it is difficult to obtain sufficient heating, and the toughness of the steel wire may be insufficient. On the other hand, if it exceeds 1150 ° C., excessive heating may result in insufficient strength or insufficient toughness due to occurrence of δ phase. When the holding time is less than 0.5 seconds, the heating time is short and it is difficult to obtain sufficient heating, and the toughness of the steel wire may be insufficient. Same 60
If the heat treatment temperature is higher than seconds, the generation of the δ phase may be increased if the heat treatment temperature is high, and the industrial cost tends to be high.

Further, in the stainless steel wire obtained after the heat treatment, the lower limit of the tensile strength before being twisted with the second wire is 800 N considering that the stainless steel wire is a wire that determines the conductor strength. / mm ² , and the upper limit is preferably 1200 N / mm ² in consideration of the workability during the twisting process. More preferably, it is 900 N / mm ² or more and less than 1100 N / mm ² .

In order to improve the corrosion resistance of the stainless steel wire, it is preferable that the martensite phase induced by wire working such as wire drawing and twisting is small or not contained. As a result of examination by the present inventors, in order to have corrosion resistance that can withstand use as a wire harness for automobiles, the metal structure of the stainless steel wire is a work-induced martensite phase: 10 vol% or less, the balance: mainly austenite phase. It was found that it is preferable that More preferably, the content of the work-induced martensite phase is 5% by volume or less.

The stability of the austenite phase and the processing conditions (area reduction rate, heat treatment conditions) mutually influence the processing-induced martensite phase. Therefore, for example, in order to control the processing-induced martensite phase to 10% by volume or less in the processing at ordinary room temperature, C + N should be contained in the above-specified range to achieve phase stabilization of the austenite phase. It is valid. Also,
During processing, the lower the ambient temperature of the stainless steel, the more easily the martensite phase is induced, so for example, die cooling during wire drawing or cooling of the take-up pot for wire drawn wire should be stopped. It is effective to raise the processing temperature.

The reasons for selecting the constituent elements of the stainless steel wire and limiting the component range will be described below. C is a strong austenite forming element. Further, it has the effect of interstitial solid solution in the crystal lattice and introducing strain to strengthen it. Furthermore,
It has the effect of forming a Cottrell atmosphere and fixing dislocations in the metallographic structure. However, when Cr carbide exists at the grain boundary, the diffusion rate of Cr in austenite is low,
A Cr-deficient layer is formed around the grain boundary, resulting in deterioration of toughness and corrosion resistance. Therefore, as an effective content, C: 0.01 mass% or more 0.
25 mass% or less.

Like C, N is a strong austenite forming element and also an interstitial solid solution strengthening element. It is also a Cottrell atmosphere forming element. However, there is a limit to the solid solution in the γ phase, and a large amount of addition (0.20 mass% or more, particularly 0.2
(More than 5% by mass) causes a blowhole during melting and casting. This phenomenon can be suppressed to some extent by increasing the solid solution limit by adding an element having a high affinity with N such as Cr and Mn. However, if it is added excessively, it is necessary to control the temperature and atmosphere during melting, which may lead to an increase in cost. Therefore, in the present invention, N: 0.01 mass% or more 0.
25 mass% or less.

Mn is used as a deoxidizing agent during melting and refining. Further, it is also effective for the phase stability of the γ phase of austenitic stainless steel and can be an alternative element of expensive Ni. It also has the effect of increasing the solid solubility limit of N in the γ phase as described above. However, Mn: 0.5% by mass or more and 4.0% by mass or less is adversely affected because the oxidation resistance at high temperature is adversely affected. Note that M
The content of n is preferably 0.5% by mass or more and 2.0% by mass or less particularly when importance is attached to the corrosion resistance, and although there is a slight decrease in the corrosion resistance, the solid solubility limit of N is increased, that is, N micro blowholes are extremely formed. When the amount is reduced, the addition of more than 2.0% by mass and 4.0% by mass or less has a great effect. In this way, the Mn content can be adjusted according to the application.

Cr is a main constituent element of austenitic stainless steel, and is an element effective for obtaining heat resistance and oxidation resistance. In the present invention, from other elemental components, Ni equivalent, Cr equivalent is calculated, after considering the phase stability of the γ phase,
16 mass% or more to obtain the heat resistance required for the wire harness, and 20 mass% or less considering deterioration of toughness.

Ni is effective in stabilizing the γ phase. In the present invention, when the content of N is 0.2 mass% or more, a large amount
The inclusion of Ni causes blowholes. In this case, it is effective to add Mn, which has a high affinity with N, and it is necessary to add Ni in consideration of the amount of Mn added in order to obtain austenitic stainless steel. Therefore, the content of Ni is set to 8.0% by mass or more for stabilizing the γ phase and 14.0% by mass or less for suppressing blowholes and suppressing cost increase. Further, the Ni content is preferably 8.0% by mass or more and 14.0% by mass or less as described above, but in the range of less than 10.0% by mass, in particular, N can be easily solid-dissolved in the melt casting step. Therefore, there is an advantage that the manufacturing cost can be further reduced.

<Second strand> In the present invention, the second strand is
At least one selected from the group consisting of copper wire, copper alloy wire, aluminum wire and aluminum alloy wire is used. Therefore, when a plurality of second strands are used, they may all be of the same type, or a plurality of types may be used in combination. When an aluminum wire or an aluminum alloy wire is used, it can be made lighter than a copper wire or a copper alloy wire. Examples of the copper wire include those whose chemical composition is copper and inevitable impurities. Copper alloy wire has chemical composition of copper, Sn, Ag, Ni,
Examples thereof include those containing one or more elements selected from the group consisting of Si, Cr, Zr, In, Al, Ti, Fe, P, Mg, Zn, and Be, and inevitable impurities. Examples of the aluminum wire include those whose chemical component is aluminum and inevitable impurities. Aluminum alloy wire consists of aluminum as a chemical component, at least one element selected from the group consisting of Mg, Si, Cu, Ti, B, Mn, Cr, Ni, Fe, Sc, and Zr, and inevitable impurities. There are things.

<Composite Wire> The composite wire of the present invention is obtained by combining and twisting the first element wire made of the stainless steel wire and the second element wire made of the metal wire such as copper. At least one each of the first strand and the second strand is used. The higher the content of the first strand, the better the strength, but the higher the conductor resistance. On the other hand, as the content of the second strand increases, the conductor resistance decreases, but the strength tends to decrease. Therefore, the numbers of the first and second strands may be appropriately selected so that appropriate conductor resistance and strength can be obtained.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. (Example 1) A composite wire was produced using a stainless steel wire and a copper wire, and the characteristics of this composite wire were examined. Table 1 shows the chemical composition of the stainless steel wire used. In Table 1, steel type: stainless steel is JIS steel type SUS304, which is a general austenitic stainless steel.

[0028]

[Table 1]

Stainless steel materials (stainless steel) having the chemical composition shown in Table 1 were melt-cast, forged and hot rolled to prepare stainless wire materials (wire diameter φ0.43 mm), and these wire materials were drawn with an area reduction rate of 86%. After processing, softening heat treatment,
A stainless steel wire having a wire diameter of 0.16 mm was obtained. The softening heat treatment was performed at a temperature of 1100 ° C. and a holding time of about 5 seconds. Table 2 shows the tensile strength of these stainless steel wires.

[0030]

[Table 2]

As shown in Table 2, the stainless steel wire may have higher tensile strength than the stainless steel wire of SUS304 even when subjected to the softening heat treatment for improving the toughness. I can confirm. Therefore, it can be seen that the stainless steel wire is excellent in both strength and toughness. Further, when the structure of the stainless steel wire after the heat treatment was examined, it was found that the work-induced martensite phase was scarcely seen and that it was an austenite phase.

The copper wire is made of almost pure copper, and is a soft wire that is often used in wire harnesses. The copper wire to be twisted with the stainless steel wire has a diameter of 0.16 mm.
For comparison with the composite wire, a stranded wire made of only copper wire was prepared, and the copper wire having a wire diameter of φ0.23 mm was prepared.

The above-mentioned element wires (stainless steel wire, copper wire) were combined and twisted into seven wires to prepare a composite wire and a copper stranded wire. Then, vinyl chloride was coated on the outer periphery of the obtained composite wire and copper stranded wire to a predetermined thickness to form an insulating layer, and an electric wire using these composite wire and copper stranded wire as a conductor was produced.

<Test Example 1> In the obtained electric wire, the breaking load of the conductor, the conductor resistance, the mass of the conductor, and the mass of the electric wire were measured. The results are shown in Table 3.

[0035]

[Table 3]

As shown in Table 3, sample Nos. 1 to 4 have a wire diameter of 0.
Compared with a stranded copper wire (Sample No. 8) consisting only of 23 mm copper wire,
It can be seen that the breaking load is equal to or more than that, and the strength is excellent. Moreover, it can be confirmed that the electric wire mass can be reduced to half or less than half. In addition, Sample Nos. 1 to 4 have a very high breaking load and excellent strength when compared with a stranded copper wire (Sample No. 7) made of only copper wire with the same strand diameter, and the wire mass is also high. It can be confirmed that it is reduced.

Further, for example, the wiring resistance is reduced by 0.5V,
When the load current is 0.5 A and the wiring length is 1.5 m, the conductor resistance of the automotive wire must be 667 mΩ / m or less,
It can be seen that sample Nos. 1 to 4 sufficiently satisfy this requirement.

Further, comparing sample No. 1 and sample No. 5 having the same ratio of stainless steel wire and copper wire, and sample No. 2 and sample No. 6, the conductor resistances are almost the same, but the sample No.1, 2
Indicates that the breaking load is larger than 10N. That is, sample Nos. 1 and 2 using a specific stainless steel wire are JIS steel type SU
It can be confirmed that the strength is superior to the electric wire using S304. The strength of Sample Nos. 5 and 6 using JIS steel type SUS304 is the same as Sample N.
To obtain the same strength as o.1 and 2, it is necessary to draw the stainless steel wire once or twice with a surface reduction rate of 20 to 30%.
However, although the martensite phase can be increased by the drawing process to improve the strength, the corrosion resistance is likely to deteriorate as described later. On the other hand, Sample Nos. 1 and 2 do not need to be drawn to improve the strength by using a stainless steel wire of a specific component, so the corrosion resistance may deteriorate due to the processing. It is also excellent in manufacturability.

The result of this test is merely an example of a wire harness, and it cannot be applied to all the application examples based on the form of the product and the numerical values of the obtained data. However, from the results of this test, it is considered that the present invention can achieve the purpose relatively easily when both high strength and high conductivity are required. Further, according to the present invention, by using the stainless steel wire having excellent strength, it is possible to reduce the usage amount of the steel wire and improve the conductivity.

<Test Example 2> Next, the corrosion resistance was evaluated.
It was The sample used in this test is the sample N used in Test Example 1 above.
o.1,2,5,6 composite wire, and work-induced martensite phase
Samples with different content ratios were prepared (Sample No.
9, 10). Sample No. 9 is the stainless steel wire used in Sample No. 1.
Uses a stainless steel material (stainless steel) with the same chemical composition as
Sample No.10 is the same as the stainless steel wire used in Sample No.5.
Uses stainless steel material (stainless steel) with similar chemical composition
By changing the processing conditions, processing-induced martensite
The content rate of gypsum was changed. Specifically, if the degree of processing is high
(Area reduction rate 96%), lower temperature softening heat treatment (temperature 1050 ℃
X Hold time 2 seconds) and at the same time around the stainless steel wire.
By lowering the temperature, the processing-induced martensite phase
The content ratio is increased. The sample No. 9 was used
Tensile strength after heat treatment of stainless steel wire is 1187N / mm ²so
there were.

The corrosion resistance test is carried out using a salt spray tester, salt water: artificial seawater (5% salt water), temperature 35 ° C., test period 1
I went as a month. The test results are shown in Table 4. In Table 4, the rusted area ratio (%) is the ratio of the total area of rusted areas to the total surface area of the composite wire.

[0042]

[Table 4]

Since stainless steel and copper have different ionization tendencies, a battery can be formed at the contact portion between the stainless steel wire and the copper wire, and it can be confirmed that corrosion progresses at the contact portion as shown in Table 4. Further, it was confirmed that the copper wire started to corrode from the contact portion, and the copper corrosion product had a bad influence on the stainless steel wire. And, sample Nos. 5 and 6 using SUS304
It can be seen that the sample Nos. 1 and 2 in which the work-induced martensite phase is controlled by a specific component are superior in corrosion resistance. Further, it can be seen that Sample No. 9 in which the processing-induced martensite phase is controlled by the processing conditions in addition to the components is also superior in corrosion resistance to Sample No. 5. In particular, as shown in Table 4, it was confirmed that the higher the content rate (volume%) of the work-induced martensite phase of the stainless steel wire, the greater the degree of progress of corrosion. Therefore, it is understood that when the martensite phase is increased by working, the tensile strength can be improved, but the corrosion resistance is deteriorated.

(Example 2) In the same manner as in Example 1 except that an aluminum wire made of pure aluminum (including inevitable impurities) having a diameter of 0.16 mm was used in place of the copper wire in Example 1 above. An electric wire using the composite wire as a conductor was prepared, and the breaking load of the conductor, the conductor resistance, the conductor mass, and the electric wire mass were measured in the same manner as in Test Example 1. As a result, the example
It was confirmed that high strength and high electrical conductivity can be achieved at the same time as in 1. It was also confirmed that the weight could be further reduced.

Generally, when a conductor is composed of only an aluminum wire, an aluminum alloy wire or a copper alloy wire, it is superior in strength as compared with a case where a conductor is composed of only a copper wire. It is difficult to expect the improvement in strength when the diameter is reduced particularly as the weight is reduced. On the other hand, the present invention can flexibly meet the required characteristics such as strength, conductivity, and weight reduction by adopting the form of twisted wire with stainless steel wire instead of only aluminum wire.

The corrosion resistance was evaluated in the same manner as in Test Example 2. When an aluminum wire, its alloy wire, or a copper alloy wire is used as the second element wire, the battery characteristics formed with the stainless steel wire are slightly different. However, it was confirmed that the same excellent corrosion resistance as in Test Example 2 was exhibited by using the stainless steel wire having the work-induced martensite content of 10% by volume or less.

[0047]

As described above, according to the composite wire for a wire harness of the present invention, a stainless steel wire having a specific chemical composition and a second element wire such as copper are twisted together to form an electric wire for an automobile. The conductor has excellent conductivity and strength, and also has an excellent effect that the corrosion resistance can be improved. In addition, the composite wire of the present invention can reduce the amount of copper used and reduce the weight by using the stainless steel wire. Further, the composite wire of the present invention does not require a manufacturing process such as a conventional clad wire or a plated wire, and can be manufactured relatively easily, so that the manufacturing cost can be reduced. And, when such a composite wire for a wire harness of the present invention is used as a conductor of an electric wire for an automobile, it is possible to improve the weight reduction and the recyclability of the entire automobile,
It is extremely effective in considering future environmental problems and has high industrial value.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01B 13/00 513 H01B 13/00 513Z (72) Inventor ▲ Taka ▼ Mura Nobue 1-1-1 Kunyokita, Itami City, Hyogo Prefecture Sumitomo Electric Steel Wire Co., Ltd. (56) Reference JP-A-6-60739 (JP, A) JP-A-1-225006 (JP, A) JP-A-1-283707 (JP, A) JP-B 7 -31939 (JP, B2) JP-B-63-23015 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01B 5/08 H01B 7/00 301 H01B 13/00 501 H01B 13 / 00 513 C22C 38/00 302 C21D 8/06

Claims (4)

(57) [Claims] 1. C: 0.01 to 0.25, N: 0.01 to 0.25, in mass%
Mn: 0.5 to 4.0, Cr: 16 to 20, Ni: 8.0 to 14.0, with the balance being Fe and impurities in a stainless steel wire with C and N contents of 0.15 mass% ≤ C + N ≤ 0.30 mass% A composite wire for a wire harness, which is formed by twisting together a first element wire satisfying the above condition and a second element wire selected from at least one kind of copper wire, copper alloy wire, aluminum wire and aluminum alloy wire. 2. The metal structure of the first strand is characterized in that the martensite phase induced by wire working is 10% by volume or less, and the balance is an austenite phase.
The composite wire for the wire harness described in. 3. The first wire is formed by drawing a stainless steel material to a predetermined wire diameter at a surface reduction rate of 5% to 98% and then at a temperature of 950 ° C.
~ 1150 ℃, holding time 0.5 seconds ~ 60 seconds heat treatment, the tensile strength before twisting with the second wire is 800N / mm ² or more 1200N /
The composite wire for a wire harness according to claim 1 or 2, which has a size of less than mm ² . 4. C: 0.01 to 0.25, N: 0.01 to 0.25, in mass%
Mn: 0.5 to 4.0, Cr: 16 to 20, Ni: 8.0 to 14.0 are contained, the balance consists of Fe and impurities, and the content of C and N is 0.15 mass% ≤
C + N ≦ 0.30% by mass of stainless steel material is drawn to a specified wire diameter with a surface reduction rate of 5% to 98%, and the drawn wire material is held at a temperature of 950 ° C to 1150 ° C for a holding time.
Heat treatment for 0.5 to 60 seconds, one or more obtained stainless steel wires, copper wire, copper alloy wire,
At least one of aluminum wire and aluminum alloy wire
With the process of twisting one or more metal wires selected from the species, the tensile strength of the stainless steel wire before twisting is 800 N / mm ²
A method of manufacturing a composite wire for a wire harness, which is not less than 1200 N / mm ² .