JP3858861B2

JP3858861B2 - Copper wire for overhead distribution lines and method for manufacturing the same

Info

Publication number: JP3858861B2
Application number: JP2003201077A
Authority: JP
Inventors: 貴朗市川; 正義青山; 和宏山田; 勉高橋; 秀寿長山
Original assignee: Hitachi Cable Ltd
Current assignee: Hitachi Cable Ltd
Priority date: 2003-07-24
Filing date: 2003-07-24
Publication date: 2006-12-20
Anticipated expiration: 2017-11-17
Also published as: JP2004043971A

Description

【０００１】
【発明の属する技術分野】
本発明は架空配電線用導体などの銅線及びその製造方法に関する。
【０００２】
【従来の技術】
時計のステッピングモ−タ、磁気記録用の磁気ヘッド、ブラウン管用のフライバックトランス等のコイル等には、直径0.02ないし0.05ｍｍの極細エナメル線が用いられている。極細エナメル線の心線には、タフピッチ銅や無酸素銅のような、酸素の含有量が0.１％以下の高純度の銅（以下、純銅と言う）が用いられている。
【０００３】
純銅は、高い導電率と熱電導性を有する利点があり、極細エナメル線の心線のほか電子機器部品のリ−ド線としても用いられている。
【０００４】
しかし、冷間加工を受けた純銅は高温で再結晶化により軟化する欠点があり、極細エナメル線の心線に用いる場合、製造工程での伸線の際の断線の重要な原因の一つとなっている。この軟化は、材料とダイスとの摩擦熱によってひきおこされ、軟化した材料はダイスによる引き抜きの張力に耐えられなくなり、断線する。この種の断線は加工度（断面減少率）が９５％以上の場合に生じ易く、従って線径が小さくなるほど、頻度は高くなる。
【０００５】
再結晶化による銅素材の軟化は室温でも進み、伸線後の経時変化による引張り強度や伸びの減少のような問題を生じている。最終線径まで伸線された銅線は、その保管中に時間の経過とともに、引張り強さ及び伸びの値が低下する。その程度は、無酸素銅と呼ばれる高純度の銅（例えば、５Ｎ、６Ｎ）で特に顕著であるが、純度が３Ｎ級のタフピッチ銅でも、伸線加工度が高い場合にはこの現象が見られる。
【０００６】
このような室温で生ずる再結晶は素材中で局部的に発生するもので、再結晶部分の金属組織を観察すると、特定の粒子が成長し、粗大化しているのが認められる。この心線をエナメル線の製造工程で焼鈍すると、新たに微細粒子が発生し、すでに存在する粗大化粒子が混在する状態となる。これが引張り強度や伸びの減少の理由と思われる。何故なら、室温での軟化が現れないような銅素材は、粒子が微細で均一な金属組織を有している。伸線ずみ銅線の室温で進む軟化は、伸線工程での加工度が高いほど、保管中の温度が高いほど、著しい。
【０００７】
伸線の際の断線や室温保管による軟化を軽減するためには、伸線の際の加工度を小さくし、荒引きから最終線径までの伸線の間の焼鈍の回数を増やすことが考えられる。
【０００８】
【発明が解決しようとする課題】
しかし、従来の極細銅線によると、伸線の際の加工度を小さくし、焼鈍の回数を増やさないと、断線を防止することができないため、製造コストが上昇する。繰り返して説明すると、極細エナメル線の心線用銅線にタフピッチ銅や無酸素銅のような、酸素の含有量が0.１％以下の高純度の銅を用いていたので、製造工程での伸線の際にしばしば断線が起こり、また伸線後の室温保管での経時変化による引張り強度や伸びの減少が見られた。伸線の際の断線は加工度が高い場合に生じ易く、伸線後の保管による引張り強度や伸びの減少も伸線工程での加工度が高いほど著しい。後者は５Ｎ以上の高純度の無酸素銅で特に顕著であるが、伸線加工度が高い場合には、純度が３Ｎ級のタフピッチ銅でも生じた。伸線の際の加工度を小さくすれば、伸線の際の断線や室温保管による軟化を軽減できるが、伸線の間の焼鈍の回数を増やす必要があり、製造コストが増大する。
【０００９】
それ故、本発明の目的は、タフピッチ銅極細銅線の、製造工程での伸線中の断線と伸線の間の焼鈍回数の増加を防止して、製造コストを低下した銅線を提供することにある。
【００１０】
本発明の他の目的は、タフピッチ銅で架空配電線用導体を形成する際に、伸線後の室温保管での経時変化による引張り強度や伸びの減少を防止することにある。
【００１１】
本発明のさらに他の目的は、タフピッチ銅による架空配電線用導体の製造方法において、伸線中の断線を防止し、伸線の間の焼鈍回数の増加を回避して、製造コストを低下するとともに、伸線後の室温保管での経時変化による引張り強度や伸びの減少を防止することにある。
【００１２】
【課題を解決するための手段】
本発明は、上記目的を達成するために、酸素含有量が２００〜４００ｐｐｍのタフピッチ銅を母材とし、その母材に、錫及びインジウムのうち１種以上の金属を５ｐｐｍ以上２００ｐｐｍ未満含有させた銅材を伸線加工した硬銅線からなる架空配電線用銅線を提供するものである。
【００１３】
本発明は、上記目的を達成するために、酸素含有量が２００〜４００ｐｐｍのタフピッチ銅の鋳造過程で、前記タフピッチ銅の溶湯に錫及びインジウムのうち１種以上の金属を５ｐｐｍ以上２００ｐｐｍ未満添加し、得られた銅材を冷間伸線することを特徴とする架空配電線用銅線の製造方法を提供するものである。
【００１４】
本発明の、または本発明により製造される、タフピッチ銅極細銅線は、最終直径が０．０２ないし０．０５ｍｍで、その引張り強度が３５kg／mm²未満の軟銅線であり、架空配電線用導体としては、最終直径２ｍｍで、単線又は撚り線として使用する。母材を構成するタフピッチ銅は、錫、インジウム又はその両方（以下、添加元素と言う）を重量で５ｐｐｍ以上、２００ｐｐｍ未満含む。タフピッチ銅とは酸素を１００ないし５００ｐｐｍ程度含む高純度の銅を言うが、通常は酸素を２００ないし４００ｐｐｍ含む。
【００１５】
錫やインジウムは酸素との親和力の高い元素であるが、酸素含有量が５００ｐｍ以下のタフピッチ銅に添加したとき、固溶体を形成し、銅の軟化温度を上昇させる。添加量は、含有量が重量で５ｐｐｍ以上、２００ｐｐｍ未満になるようにする。含有量が５ｐｐｍ未満であると、銅の軟化温度の上昇が小さく、伸線の際の断線や、伸線後の室温保管での経時変化による引張り強度や伸びの減少を充分防止することができない。極微量の添加（０．１％未満）２００ｐｐｍ以上の含有量としても、溶銅中の酸素存在下での固溶限度を超えるため、軟化温度の上昇効果は向上しない。添加元素の量を増すと、錫酸化物が増加するので好ましくない。
【００１６】
添加元素は、鋳造の際母材のタフピッチ銅に添加する。鋳造には、舟型のセラミックるつぼを用いてもよく、ＳＣＲ(Southwire Continuous Rod )のような銅荒引線連続鋳造装置を用いてもよい。連続鋳造は、鋳造工程で冷却が急速に行なわれるため、添加元素が強制固溶されるから、添加元素の効果が大きい。
【００１７】
【発明の実施の形態】
以下に、本発明の実施の形態の一例を詳細に説明する。
ＳＣＲ連続鋳造装置を用いて２００ないし４００ｐｐｍの酸素を含むタフピッチ銅を鋳造し、直径８ｍｍの荒引き線を製作した。この際、タフピッチ銅の溶銅に錫、インジウム、又は両方を、量を変えて添加して、１２通りの伸線用銅材（荒引き線）を鋳造した。
比較のため別に、６Ｎ高純度銅を小型連続鋳造機で鋳造して、直径８ｍｍの荒引き線を製作した（従来技術）。１３種類の銅材の錫およびインジウムの含有量をＩＣＰ分析により定量した結果、表１の通りであった。 No.１から No.５までは本発明による銅材、 No.６から No.１３までは比較のための本発明外の組成である。
【００１８】
【表１】

【００１９】
荒引き線の酸素含有量を測定した結果、２００ないし４００ｐｐｍの範囲内であった。直径８ｍｍの荒引き線を直径２.６ｍｍまで冷間伸線し、一旦焼鈍した後、直径０.９ｍｍまで冷間伸線し、焼鈍後、さらに直径０．０４ｍｍまで冷間伸線した。最大５０日まで保管した後、焼鈍してエナメル線の心線とした。
本発明による銅材（ No.１から No.５まで）および銅材 No.９、１０、１１、１２は伸線の過程で断線を全く生じなかった。添加元素の量の少ない銅材 No.６、７、８及び No.１３は軟化による断線を生じた。
【００２０】
【実施例】
以下に本発明の実施例を示し、本発明の効果について詳細に説明する。
［実施例１］
先に表１に示したNo.１から No.１３までの銅材の直径８ｍｍの荒引き線を直径２.６ｍｍまで冷間伸線した段階で、１２０℃から４００℃の間の温度で１時間、ソルトバス中で熱処理した。熱処理後の荒引き線について、引張り試験機を用いて引張り速度２０mm／min で引張り強さを測定した。
【００２１】
図１は、銅材No.２及び No.６について熱処理温度（℃）と引張り強さ（kg／mm²）の関係を示す。図１でσ_B（２０℃）は伸線したままの銅材（温度２０℃）の引張り強さを、σ_B(４００℃)は完全焼鈍材（熱処理温度４００℃）の引張り強さを、それぞれ意味する。引張り強さが伸線したままの銅材（σ_B（２０℃））と完全焼鈍材（σ_B(４００℃)）のちょうど中間の値［σ_B（２０℃）＋σ_B(４００℃)］／２になるような熱処理温度を半軟化温度とすると、本発明による銅材 No.２は、従来技術による No.６よりも半軟化温度が２０℃高い。このようにして半軟化温度により線材を評価した結果を表２に示す。
【００２２】
【表２】

【００２３】
本発明による銅材No.１から No.５までは、いずれも従来技術による銅材 No.６より半軟化温度が１０℃ないし２０℃高かった。添加元素含有量の少ない銅材 No.７と No.８は半軟化温度が No.６と同じであった。添加元素量が２００ｐｐｍを超える銅材 No.９、 No.１０、 No.１１は、半軟化温度が銅材 No.４、 No.５（２００℃）以上には上昇しない。錫を極端に多く添加した銅材 No.１２の半軟化温度は大きく上昇した。このように軟化温度が上がると、エナメル線等の軟銅線の心線として用いる場合に、焼鈍が難しくなる。一方、高純度銅 No.１３の半軟化温度は低く、１３３℃であった。
【００２４】
熱処理後の荒引き線について、導電率を測定した。その結果を表３に示す。
【表３】

【００２５】
表３に示すように、銅材 No.１から No.１１までの導電率はほとんど差がないが、錫を多量に添加した銅材 No.１２の導電率は大幅に低下した。銅材 No.１２は、前述のように軟化温度が大幅に上昇していたが、それは溶銅中の酸素が全て錫と反応して酸化錫となり、酸化物にならなかった錫が銅中に固溶するためである。また、錫の固溶により、導電率が大きく低下する。
【００２６】
実施の形態の項で説明したように直径０．０４ｍｍまで冷間伸線した後、室温で５０日間保管して、保管前後での機械的特性（引張り強さ、伸び）を測定した。さらに、それらを焼鈍してエナメル線（１ＵＥＷ０．０４）としたときの機械的特性を測定した。本発明による銅材 No.２、 No.３、 No.５および比較のための銅材 No.６、 No.７、 No.１３について、焼鈍前の機械的特性を測定した結果を表４に、焼鈍後の機械的特性の測定結果を表５に示す。
【００２７】
【表４】

【００２８】
【表５】

【００２９】
表４に見られるように、本発明による銅材 No.２、 No.３、 No.５は、冷間伸線後５０日保管しても引張り強さ、伸びがほとんど低下しなかった。これに対して、比較例 No.６、 No.７、 No.１３は５０日保管後に引張り強さ、伸びが著しく低下した。
【００３０】
また、表５に見られるように、本発明による銅材 No.２、 No.３、 No.５は、５０日保管した後極細線を焼鈍しても、保管による引張り強さ及び伸びの低下は僅かであった。これに対し、比較例 No.６、 No.７、 No.１３の極細線を５０日保管後の極細線を焼鈍すると、伸線直後に焼鈍したものに比し焼鈍後の引張り強さ、伸びは大幅に低下した。
【００３１】
本発明による銅材No.２、 No.３、 No.５の金属組織は、冷間伸線後、５０日保管後、極細線焼鈍後、いずれも微細な結晶粒から成っていた。これに対し、比較例 No.６、 No.７、 No.１３の金属組織は、粗大粒と微細粒が混在していた。
【００３２】
［実施例２］
本発明の又は本発明により製造される銅線は硬銅線としても用いることができる。例えば、単線又は撚り線として、絶縁体で被覆して、ケ−ブルとする。その際、絶縁体を１００℃ないし３００℃の温度で心線上に押し出すため、心線は瞬間的に高温に加熱される。そこで、架空配電線を製造する際の絶縁体押し出し工程における心線の軟化を評価した。表６は、架空配電線用導体（７／φ２．０）の絶縁体被覆前後での機械的特性（引張り強さ、伸び）を測定した結果である。
【００３３】
【表６】

【００３４】
表６に示されたように、絶縁体押し出し工程で熱を受けたとき、本発明外の銅材（ No.２４、 No.２５、 No.２６）は軟化して引張り強さが低下するのに対し、本発明による銅材（ No.２１、 No.２２、 No.２３）は軟化しない。このように、本発明の銅線の製造方法は、絶縁体被覆された硬銅線の製造にも適用できる。
【００３５】
【発明の効果】
本発明の架空配電線用銅線は、酸素含有量が２００〜４００ｐｐｍのタフピッチ銅を母材とし、その母材に、錫及びインジウムのうち１種以上の金属を５ｐｐｍ以上２００ｐｐｍ未満含有させた銅材を冷間伸線加工した硬銅線からなるため、冷間伸線、伸線後の保管、架空配電線用銅線への絶縁体押し出し工程、どの過程でも金属組織に粗大粒が発生しないから、冷間伸線で軟化による断線が発生せず、断線を避けるために冷間伸線途中での焼鈍の回数を増やす必要もないから、製造コストを抑えることができる。
【００３６】
本発明の架空配電線用銅線の製造方法によると、酸素含有量が２００〜４００ｐｐｍのタフピッチ銅の鋳造過程で、前記タフピッチ銅の溶湯に錫及びインジウムのうち１種以上の金属を５ｐｐｍ以上２００ｐｐｍ未満添加し、得られた銅材を冷間伸線加工したため、冷間伸線、伸線後の保管、架空配電線用銅線への絶縁体押し出し工程、どの過程でも金属組織に粗大粒が発生しないから、冷間伸線で軟化による断線が発生せず、断線を避けるために冷間伸線途中での焼鈍の回数を増やす必要もないから、製造コストを抑えることができる。
【図面の簡単な説明】
【図１】銅材の熱処理温度と引張り強さの関係を示すグラフである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to copper wire and a manufacturing method thereof, such as conductor hypothetical distribution lines.
[0002]
[Prior art]
Ultra-fine enamel wires having a diameter of 0.02 to 0.05 mm are used in coils such as a stepping motor of a watch, a magnetic head for magnetic recording, and a flyback transformer for a cathode ray tube. High-purity copper (hereinafter referred to as pure copper) having an oxygen content of 0.1% or less, such as tough pitch copper or oxygen-free copper, is used for the core wire of the ultrafine enamel wire.
[0003]
Pure copper has the advantage of having high electrical conductivity and thermal conductivity, and is used as a lead wire for electronic equipment components in addition to the core wire of an ultra-fine enamel wire.
[0004]
However, pure copper that has undergone cold working has the disadvantage of softening due to recrystallization at high temperatures, and when used for the core of ultra-fine enameled wire, it is one of the important causes of wire breakage during wire drawing in the manufacturing process. ing. This softening is caused by frictional heat between the material and the die, and the softened material cannot withstand the tension of drawing by the die and is disconnected. This type of disconnection is likely to occur when the degree of processing (cross-sectional reduction rate) is 95% or more, and therefore the frequency increases as the wire diameter decreases.
[0005]
The softening of the copper material due to recrystallization proceeds even at room temperature, causing problems such as a decrease in tensile strength and elongation due to changes over time after wire drawing. The copper wire drawn to the final wire diameter decreases in tensile strength and elongation as time passes during storage. The degree is particularly noticeable in high-purity copper called oxygen-free copper (for example, 5N, 6N), but this phenomenon is also seen when the degree of wire drawing is high even with 3N grade tough pitch copper. .
[0006]
Such recrystallization that occurs at room temperature occurs locally in the material. When the metallographic structure of the recrystallized portion is observed, it is recognized that specific particles grow and become coarse. When this core wire is annealed in the enamel wire manufacturing process, fine particles are newly generated, and coarse particles that already exist are mixed. This seems to be the reason for the decrease in tensile strength and elongation. This is because a copper material that does not show softening at room temperature has a fine and uniform metal structure. The softening of the drawn copper wire at room temperature is more remarkable as the degree of processing in the drawing process is higher and the temperature during storage is higher.
[0007]
In order to reduce the wire breakage during wire drawing and softening due to room temperature storage, it is considered to reduce the degree of processing during wire drawing and increase the number of annealing during wire drawing from roughing to the final wire diameter. It is done.
[0008]
[Problems to be solved by the invention]
However, according to the conventional ultra-fine copper wire, if the degree of processing at the time of wire drawing is reduced and the number of times of annealing is not increased, disconnection cannot be prevented, resulting in an increase in manufacturing cost. To repeat, high purity copper with an oxygen content of 0.1% or less, such as tough pitch copper and oxygen-free copper, was used for the copper wire for the core wire of the ultra-fine enamel wire. During wire drawing, breakage often occurred, and the tensile strength and elongation decreased due to aging during storage at room temperature after wire drawing. The wire breakage tends to occur when the degree of work is high, and the decrease in tensile strength and elongation due to storage after wire drawing is more significant as the degree of work in the wire drawing process is higher. The latter is particularly noticeable for high-purity oxygen-free copper of 5N or more, but it occurs even with 3N grade tough pitch copper when the degree of wire drawing is high. If the degree of processing at the time of wire drawing is reduced, disconnection at the time of wire drawing and softening due to storage at room temperature can be reduced, but it is necessary to increase the number of annealing during wire drawing, which increases the manufacturing cost.
[0009]
Therefore, an object of the present invention is to provide a copper wire having a reduced manufacturing cost by preventing an increase in the number of annealing between wire-drawing and wire-drawing in a manufacturing process of a tough pitch copper extra fine copper wire. There is.
[0010]
Another object of the present invention is to prevent in forming a hypothetical distribution line conductor in tough pitch copper, the decrease in tensile strength and elongation by aging at room temperature storage after drawing.
[0011]
Still another object of the present invention is to prevent breakage during wire drawing, avoid an increase in the number of annealing times during wire drawing, and reduce production cost in a method for producing a conductor for an overhead distribution line using tough pitch copper. At the same time, it is intended to prevent a decrease in tensile strength and elongation due to changes over time in room temperature storage after wire drawing.
[0012]
[Means for Solving the Problems]
The present invention, in order to achieve the above object, the oxygen content of the data Fupitchi

copper

200~400ppm as a base material, its base material, tin and one or more metals of indium is contained less 200ppm or 5ppm The present invention provides a copper wire for an aerial distribution line made of a hard copper wire obtained by drawing a copper material.
[0013]
The present invention, in order to achieve the above object, the casting process of the oxygen content 200~400ppm of data Fupitchi copper, 200 ppm less than the addition of one or more metals of 5ppm or more of the tough pitch copper tin melt and indium And the manufacturing method of the copper wire for overhead distribution lines characterized by cold-drawing the obtained copper material .
[0014]
The tough pitch copper extra fine copper wire of the present invention or manufactured according to the present invention is a soft copper wire having a final diameter of 0.02 to 0.05 mm and a tensile strength of less than 35 kg / mm ² , for overhead distribution lines The conductor has a final diameter of 2 mm and is used as a single wire or a stranded wire. The tough pitch copper constituting the base material contains 5 ppm or more and less than 200 ppm by weight of tin, indium or both (hereinafter referred to as additive elements). Tough pitch copper means high-purity copper containing about 100 to 500 ppm of oxygen, but usually contains 200 to 400 ppm of oxygen.
[0015]
Tin or indium is an element having a high affinity for oxygen, but when added to tough pitch copper having an oxygen content of 500 pm or less, it forms a solid solution and raises the softening temperature of copper. The addition amount is set so that the content is 5 ppm or more and less than 200 ppm by weight. When the content is less than 5 ppm, the increase in the softening temperature of copper is small, and it is not possible to sufficiently prevent a decrease in tensile strength and elongation due to breakage during wire drawing and changes over time in room temperature storage after wire drawing. . Even if the addition of a very small amount (less than 0.1%) is 200 ppm or more, the effect of increasing the softening temperature is not improved because it exceeds the solid solution limit in the presence of oxygen in the molten copper. Increasing the amount of additive element is not preferable because tin oxide increases.
[0016]
The additive element is added to the tough pitch copper of the base material during casting. For casting, a boat-shaped ceramic crucible may be used, or a copper rough wire continuous casting apparatus such as SCR (Southwire Continuous Rod) may be used. In continuous casting, since the cooling is rapidly performed in the casting process, the additive element is forcibly solid-solved, so the effect of the additive element is great.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an example of an embodiment of the present invention will be described in detail.
Using an SCR continuous casting apparatus, tough pitch copper containing 200 to 400 ppm of oxygen was cast to produce a rough drawn wire having a diameter of 8 mm. At this time, tin, indium, or both were added in different amounts to the molten copper of tough pitch copper to cast 12 types of copper materials for wire drawing (rough drawing wire).
For comparison, 6N high-purity copper was cast with a small continuous caster to produce a roughing wire having a diameter of 8 mm (prior art). The contents of tin and indium in 13 types of copper materials were quantified by ICP analysis, and the results are shown in Table 1. No. 1 to No. 5 are copper materials according to the present invention, and No. 6 to No. 13 are compositions outside the present invention for comparison.
[0018]
[Table 1]

[0019]
As a result of measuring the oxygen content of the rough drawn line, it was in the range of 200 to 400 ppm. A rough drawing wire having a diameter of 8 mm was cold-drawn to a diameter of 2.6 mm, annealed once, then cold-drawn to a diameter of 0.9 mm, and after annealing, the wire was further cold-drawn to a diameter of 0.04 mm. After storing for up to 50 days, it was annealed to obtain a core wire of enameled wire.
The copper materials (No. 1 to No. 5) and the copper materials No. 9, 10, 11, and 12 according to the present invention did not break at all during the wire drawing process. Copper materials No. 6, 7, 8, and No. 13 having a small amount of additive element were disconnected by softening.
[0020]
【Example】
Examples of the present invention will be shown below, and the effects of the present invention will be described in detail.
[Example 1]
In the stage where the rough drawing wire with a diameter of 8 mm of the copper materials No. 1 to No. 13 shown in Table 1 was cold-drawn to a diameter of 2.6 mm, a temperature of 120 ° C. to 400 ° C. Heat treated in a salt bath for a time. With respect to the rough drawn wire after the heat treatment, the tensile strength was measured using a tensile tester at a tensile speed of 20 mm / min.
[0021]
FIG. 1 shows the relationship between heat treatment temperature (° C.) and tensile strength (kg / mm ² ) for copper materials No. 2 and No. 6. In FIG. 1, σ _B (20 ° C.) is the tensile strength of the as-drawn copper material (temperature 20 ° C.), σ _B (400 ° C.) is the tensile strength of the fully annealed material (heat treatment temperature 400 ° C.), Each means. The intermediate value between the copper material (σ _B (20 ° C)) and the fully annealed material (σ _B (400 ° C)) with the tensile strength still drawn [σ _B (20 ° C) + σ _B (400 ° C)] Assuming that the heat treatment temperature to be / 2 is the semi-softening temperature, the copper material No. 2 according to the present invention has a semi-softening temperature of 20 ° C. higher than the No. 6 according to the prior art. Table 2 shows the results of the evaluation of the wire using the semi-softening temperature.
[0022]
[Table 2]

[0023]
The copper materials No. 1 to No. 5 according to the present invention each had a semi-softening temperature 10 ° C. to 20 ° C. higher than the copper material No. 6 according to the prior art. Copper materials No. 7 and No. 8 with low additive element content had the same semi-softening temperature as No. 6. Copper materials No. 9, No. 10, and No. 11 having an additive element amount exceeding 200 ppm do not increase the semi-softening temperature to copper materials No. 4 and No. 5 (200 ° C.) or higher. The semi-softening temperature of copper material No. 12 to which an extremely large amount of tin was added was greatly increased. When the softening temperature rises in this way, annealing becomes difficult when used as a core wire of a soft copper wire such as an enameled wire. On the other hand, the semi-softening temperature of high-purity copper No. 13 was low and was 133 ° C.
[0024]
The electrical conductivity was measured for the rough drawn wire after the heat treatment. The results are shown in Table 3.
[Table 3]

[0025]
As shown in Table 3, there is almost no difference in electrical conductivity from copper materials No. 1 to No. 11, but the electrical conductivity of copper material No. 12 to which a large amount of tin is added is greatly reduced. As described above, the softening temperature of copper material No. 12 was significantly increased, but all the oxygen in the molten copper reacted with tin to form tin oxide, and the tin that did not become an oxide contained in the copper. This is because it dissolves. In addition, the conductivity is greatly reduced due to the solid solution of tin.
[0026]
As described in the section of the embodiment, after cold drawing to a diameter of 0.04 mm, it was stored at room temperature for 50 days, and mechanical properties (tensile strength, elongation) before and after storage were measured. Furthermore, the mechanical characteristics when they were annealed to obtain enameled wire (1UEW0.04) were measured. Table 4 shows the results of measuring the mechanical properties before annealing of copper materials No. 2, No. 3, No. 5 and copper materials No. 6, No. 7, and No. 13 for comparison according to the present invention. Table 5 shows the measurement results of the mechanical properties after annealing.
[0027]
[Table 4]

[0028]
[Table 5]

[0029]
As seen in Table 4, the copper materials No. 2, No. 3, and No. 5 according to the present invention showed almost no decrease in tensile strength and elongation even after storage for 50 days after cold drawing. On the other hand, in Comparative Examples No. 6, No. 7, and No. 13, the tensile strength and elongation were remarkably reduced after 50 days storage.
[0030]
In addition, as seen in Table 5, the copper materials No. 2, No. 3, and No. 5 according to the present invention have a decrease in tensile strength and elongation due to storage even if the ultrafine wire is annealed after storage for 50 days. Was slight. In contrast, when the ultrafine wires of Comparative Examples No.6, No.7 and No.13 were annealed after storage for 50 days, the tensile strength and elongation after annealing were higher than those annealed immediately after wire drawing. Dropped significantly.
[0031]
The metal structures of the copper materials No. 2, No. 3, and No. 5 according to the present invention each consisted of fine crystal grains after cold drawing, after storage for 50 days, and after ultrafine wire annealing. On the other hand, in the metal structures of Comparative Examples No. 6, No. 7, and No. 13, coarse grains and fine grains were mixed.
[0032]
[Example 2]
The copper wire of the present invention or produced according to the present invention can also be used as a hard copper wire. For example, a single wire or a stranded wire is covered with an insulator to form a cable. At that time, since the insulator is extruded onto the core wire at a temperature of 100 ° C. to 300 ° C., the core wire is instantaneously heated to a high temperature. Then, the softening of the core wire in the insulator extrusion process at the time of manufacturing an overhead distribution line was evaluated. Table 6 shows the results of measuring the mechanical properties (tensile strength, elongation) of the overhead distribution line conductor (7 / φ2.0) before and after the insulator coating.
[0033]
[Table 6]

[0034]
As shown in Table 6, when heat is applied in the insulator extrusion process, copper materials outside the present invention (No. 24, No. 25, No. 26) soften and the tensile strength decreases. On the other hand, the copper materials (No. 21, No. 22, No. 23) according to the present invention are not softened. Thus, the manufacturing method of the copper wire of this invention is applicable also to manufacture of the hard copper wire coated with the insulator.
[0035]
【The invention's effect】
Overhead distribution lines for copper wire of the present invention, oxygen content of

data

Fupitchi copper

200~400ppm as a base material, on the base material and the tin and one or more metals of indium is contained less 200ppm or 5ppm Because it is made of hard copper wire that has been cold-drawn from copper , coarse particles are generated in the metal structure in any process , including cold drawing, storage after drawing, and extrusion of insulators into copper wires for overhead distribution lines. Therefore, disconnection due to softening does not occur in cold wire drawing, and it is not necessary to increase the number of times of annealing in the middle of cold wire drawing in order to avoid wire breakage, so that the manufacturing cost can be suppressed .
[0036]
According to the manufacturing method of the overhead distribution lines for copper wire of the present invention, the oxygen content in the casting process of

data

Fupitchi copper

200～400Ppm, the tough pitch copper one or more metals of the above 5ppm of molten tin and indium of Addition of less than 200ppm, and the resulting copper material was cold drawn , so cold drawing, storage after drawing, extrusion process of the insulator to the copper wire for overhead distribution lines , coarse grain in the metal structure in any process Therefore, the wire breakage due to softening does not occur in cold wire drawing, and it is not necessary to increase the number of times of annealing in the middle of cold wire drawing in order to avoid wire breakage, so that the manufacturing cost can be suppressed .
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the heat treatment temperature and tensile strength of a copper material.

Claims

Hard copper oxygen content and data Fupitchi copper preform 200～400Ppm, that the base material, a tin and copper material which contains less than 200ppm or 5 ppm 1 or more metals of indium cold wire drawing Copper wire for overhead distribution lines consisting of wires.

Oxygen content in the casting process of data Fupitchi copper 200～400Ppm, the tough pitch copper of the molten metal at least one metal of the tin and indium was added in less than 200ppm than 5ppm, the cold and the resulting copper material drawing The manufacturing method of the copper wire for overhead distribution lines characterized by processing .