JP4396874B2

JP4396874B2 - Manufacturing method of copper base alloy strip for terminal

Info

Publication number: JP4396874B2
Application number: JP2000075480A
Authority: JP
Inventors: 一仁一之瀬; 純一永田; 巌佐藤
Original assignee: Sumitomo Metal Mining Co Ltd
Current assignee: Sumitomo Metal Mining Co Ltd
Priority date: 2000-03-17
Filing date: 2000-03-17
Publication date: 2010-01-13
Anticipated expiration: 2020-03-17
Also published as: JP2001262297A

Description

【０００１】
【発明の属する技術分野】
本発明は、自動車用のコネクタ端子などに用いられる端子用銅基合金条およびその製造方法に関する。
【０００２】
【従来の技術】
近年のエレクトロニクスの発展に伴い、自動車のコネクタ端子などの端子は、より一層の高密度化、小型化、軽量化、そして信頼性向上が求められるようになってきている。また、エンジンの高性能化によりエンジンルーム内の温度が上昇するに伴い、エンジンルームに使用される端子も、より高信頼性及び高耐熱性が要求されるようになってきている。
【０００３】
自動車のコネクタ端子などの端子の信頼性が向上するには、具体的には、強度、ばね特性、導電性、耐応力緩和性、耐食性に優れることが必要である。例えば、導電性、耐応力緩和性を兼ね備えていないと、端子の自己発熱による酸化、めっき剥離、応力緩和、回路の電圧降下、ハウジングの軟化や変形が生じる可能性がある。
【０００４】
従来より、端子用銅基合金として用いられてきた黄銅は安価ではあるが、導電率が低く、例えばＣ２６００で２７％ＩＡＣＳであり、耐食性や耐応力緩和性にも問題があった。また、リン青銅は強度は優れているが、導電率は低く、例えばＣ５２１０で１２％ＩＡＣＳ程度であり、耐応力緩和性にも問題があり、さらに価格も高く経済的ではなかった。
【０００５】
Ｃｕ−Ｎｉ−Ｓｎ−Ｐ系合金は、これらの二種の合金の欠点を補うため開発されたものである。特公平８−９７４５号公報及び特開平４−１５４９４２号公報には、Ｃｕ−Ｎｉ−Ｓｎ−Ｐ系合金鋳塊を熱間圧延した後、冷間圧延と熱処理を繰り返して、端子用銅基合金条を製造する方法が記載されている。
【０００６】
しかしながら、このようにして製造された、例えばＣｕ−１．０Ｎｉ−０．９Ｓｎ−０．０５Ｐ（数値は重量％）の銅基合金条は、強度、耐応力緩和性については優れているものの、導電率は３８％ＩＡＣＳと低く、曲げ加工性も十分とはいえない。
【０００７】
また、この銅基合金条は、Ｎｉ−Ｐ化合物を析出させるので、溶体化熱処理を兼ねた熱間圧延が必要であり、そのための設備投資やそれに伴う諸問題の解決が必要であり、これが生産性を著しく低下させコスト高の一因となっている。具体的には、
（１）熱間圧延時に大気中での高温加熱が必要なため、材料表面に酸化スケールが発生しやすく、その除去のため多大な研削が必要となり、材料歩留まりの低下が起きると同時に、添加元素の内部酸化や圧延時の酸化スケールの巻き込み等によって内部欠陥を生じやすい。
【０００８】
（２）熱間圧延工程は、その間の温度変化を管理することは困難であり、しかも加工析出工程に相当する。つまり、熱間圧延工程中の温度変化により析出物が生じる可能性があり、しかもその析出物は粗大化しやすくなる。従って、この工程において生じた析出が、以後の工程での析出現象及び最終特性に大きな影響を及ぼしやすい。
【０００９】
（３）熱間圧延時に材料を高温に加熱するため、多くのエネルギーとそれに伴う設備投資が必要であり、生産コストの増加を招く。
【００１０】
【発明が解決しようとする課題】
本発明は、上記事情に鑑み、上記諸問題の発生源となる熱間圧延を省略した端子用銅基合金条の製造方法を、安価に提供することを目的とする。さらに、本発明は、従来のＣｕ−Ｎｉ−Ｓｎ−Ｐ合金よりも優れた導電性と曲げ加工性、さらに耐応力緩和性を有する端子用銅基合金条を提供することを目的とする。
【００１１】
【課題を解決するための手段】
本発明者らは、上記目的を達成すべく、前記課題について鋭意検討した結果、Ｃｕ−Ｎｉ−Ｓｎ−Ｐ系合金、Ｃｕ−Ｍｎ−Ｓｎ−Ｐ系合金あるいはＣｕ−Ｃｏ−Ｓｎ−Ｐ系合金において、熱間圧延を省略した最適条件を選ぶことにより、優れた強度、ばね限界値、導電率、耐応力緩和性、及び曲げ加工性が得られることを見いだし、本発明に到達した。
【００１２】
本発明の端子用銅基合金条の第１の態様は、重量％で、Ｎｉ：０．２〜３．０％、Ｓｎ：２．０％以下、Ｐ：０．００５〜２．０％を含有し、残部がＣｕと不可避的不純物であり、引張強さが５５０ＭＰａ以上、ばね限界値が４５０Ｍｐａ以上、導電率が４０％ＩＡＣＳ以上、最小曲げ半径比が１以下、かつ応力緩和率が１０％以下である。
【００１３】
本発明の端子用銅基合金条の第２の態様は、重量％で、Ｍｎ：０．２〜３．０％、Ｓｎ：２．０％以下、Ｐ：０．００５〜２．０％を含有し、残部がＣｕと不可避的不純物であり、引張強さが５５０ＭＰａ以上、ばね限界値が４５０Ｍｐａ以上、導電率が４０％ＩＡＣＳ以上、最小曲げ半径比が１以下、かつ応力緩和率が１０％以下である。
【００１４】
本発明の端子用銅基合金条の第３の態様は、重量％で、Ｃｏ：０．１〜１．０％、Ｓｎ：２．０％以下、Ｐ：０．００５〜１．０％を含有し、残部がＣｕと不可避的不純物であり、引張強さが６００ＭＰａ以上、ばね限界値が５００Ｍｐａ以上、導電率が５０％ＩＡＣＳ以上、最小曲げ半径比が１以下、かつ応力緩和率が１０％以下である。
【００１５】
本発明の端子用銅基合金条の製造方法の第１の態様は、重量％で、Ｎｉ：０．２〜３．０％、Ｓｎ：２．０％以下、Ｐ：０．００５〜２．０％を含有し、残部がＣｕと不可避的不純物である、銅基合金を連続鋳造する第一工程、非酸化性雰囲気中で熱処理温度を５００〜９５０℃として均質化焼鈍する第二工程、冷間圧延した後に非酸化性雰囲気中で焼鈍温度を４５０〜６５０℃として中間焼鈍することを１回以上行い、最後の中間焼鈍前の圧延率を８５％以上とする第三工程、圧延率を３０〜９０％として仕上げ冷間圧延する第四工程、及び焼鈍温度を２５０〜４００℃として低温焼鈍する第五工程からなる。
【００１６】
第三工程で得られた中間焼鈍物が、５μｍ以下の再結晶粒径を有し、ＮｉとＰの一部が２０ｎｍ以下のＮｉ−Ｐ系金属間化合物となってマトリクス中に均一微細に析出した組織を有する。
【００１７】
本発明の端子用銅基合金条の製造方法の第２の態様は、重量％で、Ｍｎ：０．２〜３．０％、Ｓｎ：２．０％以下、Ｐ：０．００５〜２．０％を含有し、残部がＣｕと不可避的不純物である、銅基合金を連続鋳造する第一工程、非酸化性雰囲気中で熱処理温度を５００〜９５０℃として均質化焼鈍する第二工程、冷間圧延した後に非酸化性雰囲気中で焼鈍温度を４５０〜６５０℃として中間焼鈍することを１回以上行い、最後の中間焼鈍前の圧延率を８５％以上とする第三工程、圧延率を３０〜９０％として仕上げ冷間圧延する第四工程、及び焼鈍温度を２５０〜４００℃として低温焼鈍する第五工程からなる。
【００１８】
第三工程で得られた中間焼鈍物が、５μｍ以下の再結晶粒径を有し、ＭｎとＰの一部が２０ｎｍ以下のＭｎ−Ｐ系金属間化合物となってマトリクス中に均一微細に析出した組織を有する。
【００１９】
本発明の端子用銅基合金条の製造方法の第３の態様は、重量％で、Ｃｏ：０．１〜１．０％、Ｓｎ：２．０％以下、Ｐ：０．００５〜１．０％を含有し、残部がＣｕと不可避的不純物である、銅基合金を連続鋳造する第一工程、非酸化性雰囲気中で熱処理温度を５００〜９８０℃として均質化焼鈍する第二工程、冷間圧延した後に非酸化性雰囲気中で焼鈍温度を４５０〜６５０℃として中間焼鈍することを１回以上行い、最後の中間焼鈍前の圧延率を８５％以上とする第三工程、圧延率を３０〜９０％として仕上げ冷間圧延する第四工程、及び焼鈍温度を３００〜４５０℃として低温焼鈍する第五工程からなる。
【００２０】
第三工程で得られた中間焼鈍物が、５μｍ以下の再結晶粒径を有し、ＣｏとＰの一部が２０ｎｍ以下のＣｏ−Ｐ系金属間化合物となってマトリクス中に均一微細に析出した組織を有する。
【００２１】
なお、前記第１〜第３の態様の端子用銅基合金条は、各々、前記第１〜第３の態様による製造方法によって製造される。
【００２２】
【発明の実施の形態】
（１）合金元素
本発明の銅基合金中の添加元素、及び本発明の銅基合金条の製造方法の第一工程で銅基合金鋳塊を溶製する際の添加元素は、次の作用効果を持つ。
【００２３】
（ａ）Ｎｉ、Ｍｎ、Ｃｏ
Ｎｉ（またはＭｎ、Ｃｏ）はＣｕマトリクス中に固溶して、強度・ばね特性及び耐応力緩和性を向上させる。また、共存するＰと形成したＮｉ−Ｐ系金属間化合物（Ｎｉ₃Ｐ）（またはＭｎ−Ｐ系金属間化合物（Ｍｎ₃Ｐ）、Ｃｏ−Ｐ系金属間化合物（Ｃｏ₂Ｐ））は、マトリクス中に均一微細に分散析出して、導電性を向上させ、強度・ばね特性・耐応力緩和性をさらに向上させる。
【００２４】
上記Ｎｉ（またはＭｎ、Ｃｏ）の作用効果は、Ｎｉ、Ｍｎが０．２重量％未満、Ｃｏが０．１重量％未満では十分得ることができず、Ｎｉ、Ｍｎが３．０重量％、Ｃｏが１．０重量％を超えると飽和してしまう。従って、Ｎｉ、Ｍｎは０．２重量％以上、３．０重量％以下が望ましく、Ｃｏは、０．１重量％以上、１．０重量％以下が望ましい。
【００２５】
（ｂ）Ｓｎ
Ｓｎは、Ｃｕマトリクス中に固溶して強度・ばね特性を向上させる。
【００２６】
上記Ｓｎの作用効果は、Ｓｎ成分が２．０重量％を超えると飽和してしまう。従って、Ｓｎ成分は２．０重量％以下が望ましい。
【００２７】
（ｃ）Ｐ
Ｐは、Ｃｕマトリクス中に固溶しているだけでなく、分散析出するＮｉ−Ｐ系金属間化合物（Ｎｉ₃Ｐ）（またはＭｎ−Ｐ系金属間化合物（Ｍｎ₃Ｐ）、Ｃｏ−Ｐ系金属間化合物（Ｃｏ₂Ｐ））を共存させるＮｉ（またはＭｎ、Ｃｏ）と形成する。これにより、強度・導電性・ばね特性、及び耐応力緩和性を向上させる。
【００２８】
上記Ｐの作用効果は、Ｐ成分が０．００５重量％未満では十分得ることができず、Ｐ成分が、Ｃｕ−Ｎｉ（Ｍｎ）−Ｓｎ−Ｐ系合金では２．０重量％、Ｃｕ−Ｃｏ−Ｓｎ−Ｐ系合金では１．０重量％を超えると飽和してしまう。従って、Ｐ成分は０．００５重量％以上が必要で、Ｃｕ−Ｎｉ（Ｍｎ）−Ｓｎ−Ｐ系合金では２．０重量％以下、Ｃｕ−Ｃｏ−Ｓｎ−Ｐ系合金では１．０重量％以下が望ましい。
【００２９】
（２）均質化焼鈍
均質化焼鈍は、固溶元素の偏析を無くし、しかもＮｉ（またはＭｎ、Ｃｏ）とＰを十分固溶させるために行う。この固溶状態から、後工程でＮｉ₃Ｐ化合物（またはＭｎ₃Ｐ化合物、Ｃｏ₂Ｐ化合物）として時効析出させる。熱処理温度が５００℃未満では、温度が低く、十分に元素の偏析を取り除けず、しかもＮｉ（またはＭｎ、Ｃｏ）とＰが固溶した単相（過飽和固溶体）とはならない。一方、Ｃｕ−Ｎｉ（Ｍｎ）−Ｓｎ−Ｐ系合金では９５０℃、Ｃｕ−Ｃｏ−Ｓｎ−Ｐ系合金では９８０℃より高い温度になると、その温度が融点近傍であるとともに、曲げ加工性を十分向上させることが不可能となってしまう。何故なら、結晶粒径が粗大化し、後工程の冷間圧延・中間焼鈍における（仕上げ圧延に供する）再結晶粒径を５μｍ以下に調整することができなくなるからである。
【００３０】
また、上記均質化焼鈍処理を非酸化性雰囲気で行うのは、材料表面の酸化及び内部酸化を抑制するためである。
【００３１】
この時、常温で単相（過飽和状態）組織にするために、均質化焼鈍した鋳塊を急冷する。この急冷は、通常行われている水冷・空冷・油冷などにより行えばよい。
【００３２】
（３）冷間圧延・中間焼鈍
上記急冷で得たコイルは、冷間圧延した後、焼鈍温度を４５０〜６５０℃として中間焼鈍する。この冷間圧延・中間焼鈍は、１回で済ませてもよいが、効率よく冷間圧延を行うために複数回行ってもよい。１回で済ませる場合は、圧延率を８５％以上として冷間圧延した後、焼鈍温度を４５０〜６５０℃として中間焼鈍する。また、複数回行う場合は、冷間圧延し、次に焼鈍温度を４５０〜６５０℃として中間焼鈍した後、該冷間圧延及び該中間焼鈍する一連の操作を繰り返すが、このとき最後の中間焼鈍前の冷間圧延率は必ず８５％以上とする。このように冷間圧延率の圧延率を８５％以上とするのは、５μｍ以下の再結晶粒径にするためである。時効析出するＮｉ₃Ｐ化合物（またはＭｎ₃Ｐ化合物、Ｃｏ₂Ｐ化合物）の粒径は、Ｎｉ（またはＭｎ、Ｃｏ）とＰとの組成にもよるが２０ｎｍ以下で微細である。冷間圧延・中間焼鈍において再結晶が十分進行しないか、再結晶粒径が５μｍを超えると、曲げ加工性を十分向上させることが不可能となってしまう。
【００３３】
圧延率が８５％未満では、後工程の仕上げ圧延に供する再結晶粒径を５μｍ以下に調整することが難しくなる。また、中間焼鈍温度が４５０℃未満では再結晶が十分進行せず、一方６５０℃より高い温度になると再結晶粒径が５μｍより粗大になってしまう。
【００３４】
（４）仕上げ冷間圧延
仕上げ冷間圧延の圧延率は、３０〜９０％とする。３０％未満では強度及び耐応力緩和性が低下し、一方９０％を超えると曲げ加工性が低下する。
【００３５】
（５）低温焼鈍
Ｎｉ₃Ｐ化合物（またはＭｎ₃Ｐ化合物、Ｃｏ₂Ｐ化合物）を十分析出させると同時に、再結晶を進行させることなく歪取りを行って、十分な曲げ加工性を与えるために行う。そのために、低温焼鈍温度をＣｕ−Ｎｉ（Ｍｎ）−Ｓｎ−Ｐ系合金では２５０〜４００℃、Ｃｕ−Ｃｏ−Ｓｎ−Ｐ系合金では３００〜４５０℃とする。この最低温度未満では、上記反応が起こらず曲げ加工性が低下する。一方、前記最高温度を超えると、歪取りは行えるが再結晶が進行してしまい、強度及び耐応力緩和性が低下する。
【００３６】
（６）特性の測定
引張強さ、導電率、ばね限界値の測定は、ＪＩＳＨ２２４１、ＪＩＳＨ０５０５、ＪＩＳＨ３１３０に準拠した。曲げ加工性については、９０°Ｗ曲げ加工試験で評価した。試験はＣＥＳ−Ｍ０００２−６に準拠し、曲げ半径が０．１〜２．０の治具で９０°Ｗ曲げ加工し、中央山表面の状況を調べた。なお、曲げ軸は圧延方向に対して平行方向（ＢａｄＷａｙ）とした。そして、割れ及びシワが発生しない最小曲げ半径Ｒを板厚ｔで割った値、すなわち最小曲げ半径比Ｒ／ｔを求めた。最小曲げ半径比が小さいほど曲げ加工性が良い。応力緩和試験では、試験片の中央部の応力が耐力の８０％となるようにアーチ曲げを行い、１５０℃の温度で１０００時間保持した後、試験片の曲げぐせを応力緩和率として次式により算出した。なお、次式において、Ｌ₀は冶具の長さ（ｍｍ）、Ｌ₁は曲げぐせをつける前の試料端間の水平距離（ｍｍ）、Ｌ₂は曲げぐせをつけた後の試料端間の水平距離（ｍｍ）である。
【００３７】
応力緩和率（％）＝（Ｌ₁−Ｌ₂）／（Ｌ₁−Ｌ₀）×１００
【００３８】
（実施例）
以下、実施例１、２、比較例１〜７、従来例１、２により本発明を説明する。なお、これらの実施例、比較例及び従来例における合金組成を表１に記載し、また主な製造条件も示した。
【００３９】
（実施例１、２）
（１）合金鋳塊の溶製・連続鋳造
表１の実施例１、２に示される組成の合金を横型連続鋳造法により、各々厚さ１７ｍｍ、幅６００ｍｍに鋳造し、次いでこの鋳塊を厚さ両面１ｍｍずつ面削した。
【００４０】
（２）均質化焼鈍
合金鋳塊を非酸化性雰囲気中において８５０℃で２時間均質化焼鈍を行った後、空冷した。
【００４１】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を冷間圧延して厚さ０．６３ｍｍの板材となし（圧延率９６％）、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの実施例においても３μｍであり、しかもＮｉ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【００４２】
（４）仕上げ冷間圧延
連続焼鈍した板材に圧延率６０％の冷間圧延を施した。
【００４３】
（５）低温焼鈍
この連続焼鈍炉にて窒素雰囲気中、３５０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【００４４】
（比較例１、２）
（１）合金鋳塊の溶製・連続鋳造：表１の比較例１、２に示される合金の製造を、実施例１と同様に行った。
【００４５】
（２）均質化焼鈍
合金鋳塊を非酸化性雰囲気中において、比較例１は４５０℃で５時間、比較例２は９８０℃で２時間均質化焼鈍を行った後、空冷した。
【００４６】
（３）冷間圧延・中間焼鈍
実施例１と同様に行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、比較例１においては３μｍであり、比較例２においては１５μｍであった。また、Ｎｉ−Ｐ金属間化合物は、比較例１においては１μｍ以下の大きさで不均一に析出しており、比較例２においては２０ｎｍ以下の大きさで均一微細に析出していた。
【００４７】
（４）仕上げ冷間圧延：実施例１と同様に行った。
【００４８】
（５）低温焼鈍：実施例１と同様に行った。
【００４９】
（比較例３）
（１）合金鋳塊の溶製・連続鋳造：表１の比較例３に示される合金の製造を、実施例１と同様に行った。
【００５０】
（２）均質化焼鈍：実施例１と同様に行った。
【００５１】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を圧延率７８％とし冷間圧延して厚さ３．０ｍｍの板材となし、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。次に、この連続焼鈍物を再び圧延率７８％とし冷間圧延して厚さ０．６５ｍｍの板材となし、同様な連続焼鈍処理を施した。この連続焼鈍で得られた板材（合金条）の再結晶粒径は１０μｍであり、しかもＮｉ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【００５２】
（４）仕上げ冷間圧延：実施例１と同様に行った。
【００５３】
（５）低温焼鈍：実施例１と同様に行った。
【００５４】
（比較例４、５）
（１）合金鋳塊の溶製・連続鋳造：表１の比較例４、５に示される合金の製造を、実施例１と同様に行った。
【００５５】
（２）均質化焼鈍：実施例１と同様に行った。
【００５６】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を冷間圧延して厚さ０．６３ｍｍの板材となし（圧延率９６％）、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で比較例４は４００℃に、比較例５は７００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶組織は、比較例４においては部分再結晶組織であり、比較例５においては結晶粒径１０μｍの完全再結晶となっていた。また、Ｎｉ−Ｐ金属間化合物は、比較例４においては析出しておらず、比較例５においては５０ｎｍ以下の大きさで均一析出していた。
【００５７】
（４）仕上げ冷間圧延：実施例１と同様に行った。
【００５８】
（５）低温焼鈍：実施例１と同様に行った。
【００５９】
（比較例６、７）
（１）合金鋳塊の溶製・連続鋳造：表１の比較例６、７に示される合金の製造を、実施例１と同様に行った。
【００６０】
（２）均質化焼鈍：実施例１と同様に行った。
【００６１】
（３）冷間圧延・中間焼鈍
実施例１と同様に行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの比較例においても３μｍであり、しかもＮｉ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【００６２】
（４）仕上げ冷間圧延：実施例１と同様に行った。
【００６３】
（５）低温焼鈍
この連続焼鈍炉にて窒素雰囲気中、比較例６は２３０℃の低温焼鈍処理を、比較例７は４３０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【００６４】
（従来例１、２）
表１の従来例１、２に示される組成からなる合金を大気溶解炉で溶製した。次に、この合金鋳塊を８５０℃で加熱し、厚さ１７ｍｍまで熱間圧延した後、常温の水中に浸漬して急冷した。急冷した熱間圧延物の表面を面削して厚さ１５ｍｍとした後、冷間圧延して厚さ０．６３ｍｍの板材となし、連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの従来例においても３μｍであり、しかもＮｉ−Ｐ金属間化合物は５０ｎｍ以下の大きさで不均一に析出していた。次に、この連続焼鈍した板材に圧延率６０％の冷間圧延を施し、連続焼鈍炉にて窒素雰囲気中、３５０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【００６５】
このようにして得られた板材（合金条）について、引張強さ、導電率、ばね限界値を測定値を測定するとともに、曲げ加工性、応力緩和性を調査した。結果を表２に示す。
【００６６】
【表１】

【００６７】
【表２】

【００６８】
以下、実施例３、４、比較例８〜１４、従来例３、４により本発明を説明する。なお、これらの実施例、比較例及び従来例における合金組成を表３に記載し、また主な製造条件も示した。
【００６９】
（実施例３、４）
（１）合金鋳塊の溶製・連続鋳造
表３の実施例３、４に示される組成の合金を横型連続鋳造法により、各々厚さ１５ｍｍ、幅６００ｍｍに鋳造し、次いでこの鋳塊を厚さ両面１ｍｍずつ面削した。
【００７０】
（２）均質化焼鈍
合金鋳塊を非酸化性雰囲気中において８５０℃で２時間均質化焼鈍を行った後、空冷した。
【００７１】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を冷間圧延して厚さ０．６３ｍｍの板材となし（圧延率９６％）、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの実施例においても３μｍであり、しかもＭｎ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【００７２】
（４）仕上げ冷間圧延
連続焼鈍した板材に圧延率６０％の冷間圧延を施した。
【００７３】
（５）低温焼鈍
この連続焼鈍炉にて窒素雰囲気中、３５０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【００７４】
（比較例８、９）
（１）合金鋳塊の溶製・連続鋳造：表３の比較例８、９に示される合金について、実施例３と同様に行った。
【００７５】
（２）均質化焼鈍
合金鋳塊を非酸化性雰囲気中において、比較例８は４５０℃で５時間、比較例９は９８０℃で２時間均質化焼鈍を行った後、空冷した。
【００７６】
（３）冷間圧延・中間焼鈍
実施例３と同様に行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、比較例８においては３μｍであり、比較例９においては１５μｍであった。また、Ｍｎ−Ｐ金属間化合物は、比較例８においては１μｍ以下の大きさで不均一に析出しており、比較例９においては２０ｎｍ以下の大きさで均一微細に析出していた。
【００７７】
（４）仕上げ冷間圧延：実施例３と同様に行った。
【００７８】
（５）低温焼鈍：実施例３と同様に行った。
【００７９】
（比較例１０）
（１）合金鋳塊の溶製・連続鋳造：表３の比較例１０に示される合金について、実施例３と同様に行った。
【００８０】
（２）均質化焼鈍：実施例３と同様に行った。
【００８１】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を圧延率７８％とし冷間圧延して厚さ３．０ｍｍの板材となし、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。次に、この連続焼鈍した板材を再び圧延率７８％とし冷間圧延して厚さ０．６５ｍｍの板材となし、同様な連続焼鈍処理を施した。この連続焼鈍で得られた板材（合金条）の再結晶粒径は１０μｍであり、しかもＭｎ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【００８２】
（４）仕上げ冷間圧延：実施例３と同様に行った。
【００８３】
（５）低温焼鈍：実施例３と同様に行った。
【００８４】
（比較例１１、１２）
（１）合金鋳塊の溶製・連続鋳造：表３の比較例１１、１２に示される合金について、実施例３と同様に行った。
【００８５】
（２）均質化焼鈍：実施例３と同様に行った。
【００８６】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を冷間圧延して厚さ０．６３ｍｍの板材となし（圧延率９６％）、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で比較例１１は４００℃に、比較例１２は７００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶組織は、比較例１１においては部分再結晶組織であり、比較例１２においては結晶粒径１０μｍの完全再結晶となっていた。また、Ｍｎ−Ｐ金属間化合物は、比較例１１においては析出しておらず、比較例１２においては５０ｎｍ以下の大きさで均一析出していた。
【００８７】
（４）仕上げ冷間圧延：実施例３と同様に行った。
【００８８】
（５）低温焼鈍：実施例３と同様に行った。
【００８９】
（比較例１３、１４）
（１）合金鋳塊の溶製・連続鋳造：表３の比較例１３、１４に示される合金について、実施例３と同様に行った。
【００９０】
（２）均質化焼鈍：実施例３と同様に行った。
【００９１】
（３）冷間圧延・中間焼鈍
実施例３と同様に行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの比較例においても３μｍであり、しかもＭｎ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【００９２】
（４）仕上げ冷間圧延：実施例３と同様に行った。
【００９３】
（５）低温焼鈍
この連続焼鈍炉にて窒素雰囲気中、比較例１３は２３０℃の低温焼鈍処理を、比較例１４は４３０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【００９４】
（従来例３、４）
表３の従来例３、４に示される組成からなる合金を、各々大気溶解炉で溶製した。次に、この合金鋳塊を８５０℃で加熱し、厚さ１５ｍｍまで熱間圧延した後、常温の水中に浸漬して急冷した。急冷した熱間圧延物の表面を面削して厚さ１３ｍｍとした後、冷間圧延して厚さ０．６３ｍｍの板材となし、連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの従来例においても３μｍであり、しかもＭｎ−Ｐ金属間化合物は５０ｎｍ以下の大きさで不均一に析出していた。次に、この連続焼鈍した板材に圧延率６０％の冷間圧延を施し、連続焼鈍炉にて窒素雰囲気中、３５０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【００９５】
このようにして得られた板材（合金条）について、引張強さ、導電率、ばね限界値を測定値を測定するとともに、曲げ加工性、応力緩和性を調査した。結果を表４に示す。
【００９６】
【表３】

【００９７】
【表４】

【００９８】
以下、実施例５、６、比較例１５〜２１、従来例５、６により本発明を説明する。なお、これらの実施例、比較例及び従来例における合金組成を表５に記載し、また主な製造条件も示した。
【００９９】
（実施例５、６）
（１）合金鋳塊の溶製・連続鋳造
表５の実施例５、６に示される組成の合金を横型連続鋳造法により、各々厚さ１５ｍｍ、幅６００ｍｍに鋳造し、次いでこの鋳塊を厚さ両面１ｍｍずつ面削した。
【０１００】
（２）均質化焼鈍
合金鋳塊を非酸化性雰囲気中において９５０℃で２時間均質化焼鈍を行った後、空冷した。
【０１０１】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を冷間圧延して厚さ０．６３ｍｍの板材となし（圧延率９６％）、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの実施例においても３μｍであり、しかもＣｏ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【０１０２】
（４）仕上げ冷間圧延
連続焼鈍した板材に圧延率６０％の冷間圧延を施した。
【０１０３】
（５）低温焼鈍
この連続焼鈍炉にて窒素雰囲気中、４００℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【０１０４】
（比較例１５、１６）
（１）合金鋳塊の溶製・連続鋳造：表５の比較例１５、１６に示される合金について、実施例５と同様に行った。
【０１０５】
（２）均質化焼鈍
合金鋳塊を非酸化性雰囲気中において、比較例１５は４５０℃で５時間、比較例１６は１０００℃で２時間均質化焼鈍を行った後、空冷した。
【０１０６】
（３）冷間圧延・中間焼鈍
実施例５と同様に行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、比較例１５においては３μｍであり、比較例１６においては１５μｍであった。また、Ｃｏ−Ｐ金属間化合物は、比較例１５においては１μｍ以下の大きさで不均一に析出しており、比較例１６においては２０ｎｍ以下の大きさで均一微細に析出していた。
【０１０７】
（４）仕上げ冷間圧延：実施例５と同様に行った。
【０１０８】
（５）低温焼鈍：実施例５と同様に行った。
【０１０９】
（比較例１７）
（１）合金鋳塊の溶製・連続鋳造：表５の比較例１７に示される合金について、実施例５と同様に行った。
【０１１０】
（２）均質化焼鈍：実施例５と同様に行った。
【０１１１】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を圧延率７８％とし冷間圧延して厚さ３．０ｍｍの板材となし、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。次に、この連続焼鈍した板材を再び圧延率７８％とし冷間圧延して厚さ０．６５ｍｍの板材となし、同様な連続焼鈍処理を施した。この連続焼鈍で得られた板材（合金条）の再結晶粒径は１０μｍであり、しかもＣｏ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【０１１２】
（４）仕上げ冷間圧延：実施例５と同様に行った。
【０１１３】
（５）低温焼鈍：実施例５と同様に行った。
【０１１４】
（比較例１８、１９）
（１）合金鋳塊の溶製・連続鋳造：表５の比較例１８、１９に示される合金について、実施例５と同様に行った。
【０１１５】
（２）均質化焼鈍：実施例５と同様に行った。
【０１１６】
（３）冷間圧延・中間焼鈍
空冷した均質化焼鈍物を冷間圧延して厚さ０．６３ｍｍの板材となし（圧延率９６％）、この板材に連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で比較例１８は４００℃に、比較例１９は７００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶組織は、比較例１８においては部分再結晶組織であり、比較例１９においては結晶粒径１０μｍの完全再結晶となっていた。また、Ｃｏ−Ｐ金属間化合物は、比較例１８においては析出しておらず、比較例１９においては５００ｎｍ以下の大きさで均一析出していた。
【０１１７】
（４）仕上げ冷間圧延：実施例５と同様に行った。
【０１１８】
（５）低温焼鈍：実施例５と同様に行った。
【０１１９】
（比較例２０、２１）
（１）合金鋳塊の溶製・連続鋳造：表５の比較例２０、２１に示される合金について、実施例５と同様に行った。
【０１２０】
（２）均質化焼鈍：実施例５と同様に行った。
【０１２１】
（３）冷間圧延・中間焼鈍
実施例５と同様に行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの比較例においても３μｍであり、しかもＣｏ−Ｐ金属間化合物は２０ｎｍ以下の大きさで均一微細に析出していた。
【０１２２】
（４）仕上げ冷間圧延：実施例５と同様に行った。
【０１２３】
（５）低温焼鈍
この連続焼鈍炉にて窒素雰囲気中、比較例２０は２８０℃の低温焼鈍処理を、比較例２１は４８０℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【０１２４】
（従来例５、６）
表５の従来例５、６に示される組成からなる合金を、各々大気溶解炉で溶製した。次に、この合金鋳塊を９５０℃で加熱し、厚さ１５ｍｍまで熱間圧延した後、常温の水中に浸漬して急冷した。急冷した熱間圧延物の表面を面削して厚さ１３ｍｍとした後、冷間圧延して厚さ０．６３ｍｍの板材となし、連続焼鈍処理を施した。連続焼鈍処理は、板材を窒素雰囲気中で６００℃に保持した加熱炉中を８ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。この連続焼鈍で得られた板材（合金条）の再結晶粒径は、いずれの従来例においても３μｍであり、しかもＣｏ−Ｐ金属間化合物は５０ｎｍ以下の大きさで不均一に析出していた。次に、この連続焼鈍した板材に圧延率６０％の冷間圧延を施し、連続焼鈍炉にて窒素雰囲気中、４００℃の低温焼鈍処理を１０ｍ／ｍｉｎで走行させ、炉から出てくる板材に冷却水を噴射して行った。
【０１２５】
このようにして得られた材料について、引張強さ、導電率、ばね限界値を測定値を測定するとともに、曲げ加工性、応力緩和性を調査した。結果を表６に示す。
【０１２６】
【表５】

【０１２７】
【表６】

【０１２８】
【発明の効果】
本発明の方法は、材料作製中に表面酸化スケールの発生、粗大な金属間化合物の析出等の問題となる熱間圧延工程を省略し、特性の優れた端子用銅基合金条およびその製造方法を提供するもので、熱間圧延時の材料を高温に加熱するためのエネルギーとそれに伴う設備投資を必要とせず、歩留まりを向上し、生産コストを低減できる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a copper-based alloy strip for terminals used for automobile connector terminals and the like, and a method for producing the same.
[0002]
[Prior art]
With the recent development of electronics, terminals such as automobile connector terminals are required to have higher density, smaller size, lighter weight, and improved reliability. Further, as the temperature in the engine room rises due to higher performance of the engine, terminals used in the engine room are required to have higher reliability and higher heat resistance.
[0003]
In order to improve the reliability of terminals such as connector terminals of automobiles, specifically, it is necessary to have excellent strength, spring characteristics, conductivity, stress relaxation resistance, and corrosion resistance. For example, if both conductivity and stress relaxation resistance are not provided, there is a possibility that oxidation due to self-heating of the terminal, plating peeling, stress relaxation, circuit voltage drop, and softening or deformation of the housing may occur.
[0004]
Conventionally, brass that has been used as a copper-based alloy for terminals is inexpensive, but has a low electrical conductivity, for example, 27% IACS at C2600, which also has problems with corrosion resistance and stress relaxation resistance. Phosphor bronze is excellent in strength but low in electrical conductivity. For example, C5210 is about 12% IACS, has a problem in stress relaxation resistance, and is expensive and not economical.
[0005]
Cu-Ni-Sn-P based alloys have been developed to compensate for the disadvantages of these two alloys. Japanese Patent Publication No. 8-9745 and Japanese Patent Application Laid-Open No. 4-154944 disclose a copper-based alloy for terminals after hot rolling a Cu—Ni—Sn—P alloy ingot, followed by cold rolling and heat treatment. A method of manufacturing the strip is described.
[0006]
However, the copper-based alloy strip of, for example, Cu-1.0Ni-0.9Sn-0.05P (numerical value is% by weight) manufactured in this way is excellent in strength and stress relaxation resistance. The electrical conductivity is as low as 38% IACS, and the bending workability is not sufficient.
[0007]
Moreover, since this copper-based alloy strip precipitates a Ni-P compound, it requires hot rolling that also serves as a solution heat treatment, and it is necessary to solve the problems associated with the capital investment and the production. This significantly reduces the performance and contributes to the high cost. In particular,
(1) Since high temperature heating in the atmosphere is required during hot rolling, oxide scale is likely to be generated on the surface of the material, and a large amount of grinding is required to remove it. Internal defects are likely to occur due to internal oxidation of the steel and the involvement of oxide scale during rolling.
[0008]
(2) In the hot rolling process, it is difficult to manage the temperature change during the process, and it corresponds to the work precipitation process. That is, a precipitate may be generated due to a temperature change during the hot rolling process, and the precipitate is easily coarsened. Therefore, the precipitation generated in this step tends to have a great influence on the precipitation phenomenon and the final characteristics in the subsequent steps.
[0009]
(3) Since the material is heated to a high temperature during hot rolling, a large amount of energy and accompanying equipment investment are required, which leads to an increase in production cost.
[0010]
[Problems to be solved by the invention]
An object of this invention is to provide the manufacturing method of the copper base alloy strip for terminals which abbreviate | omitted the hot rolling used as the generation source of the said various problems in view of the said situation at low cost. Furthermore, an object of the present invention is to provide a copper-based alloy strip for a terminal having conductivity and bending workability superior to those of a conventional Cu-Ni-Sn-P alloy and further having stress relaxation resistance.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present inventors have made extensive studies on the above problems, and as a result, Cu-Ni-Sn-P alloys, Cu-Mn-Sn-P alloys or Cu-Co-Sn-P alloys. Thus, the inventors have found that excellent strength, spring limit value, electrical conductivity, stress relaxation resistance, and bending workability can be obtained by selecting the optimum conditions without hot rolling.
[0012]
1st aspect of the copper base alloy strip for terminals of this invention is weight%, Ni: 0.2-3.0%, Sn: 2.0% or less, P: 0.005-2.0% And the balance is Cu and inevitable impurities, the tensile strength is 550 MPa or more, the spring limit value is 450 Mpa or more, the conductivity is 40% IACS or more, the minimum bending radius ratio is 1 or less, and the stress relaxation rate is 10%. It is as follows.
[0013]
The 2nd aspect of the copper-based alloy strip for terminals of this invention is weight%, Mn: 0.2-3.0%, Sn: 2.0% or less, P: 0.005-2.0% And the balance is Cu and inevitable impurities, the tensile strength is 550 MPa or more, the spring limit value is 450 Mpa or more, the conductivity is 40% IACS or more, the minimum bending radius ratio is 1 or less, and the stress relaxation rate is 10%. It is as follows.
[0014]
In the third aspect of the copper-based alloy strip for terminals of the present invention, Co: 0.1 to 1.0%, Sn: 2.0% or less, and P: 0.005 to 1.0% by weight. And the balance is Cu and inevitable impurities, the tensile strength is 600 MPa or more, the spring limit value is 500 Mpa or more, the conductivity is 50% IACS or more, the minimum bending radius ratio is 1 or less, and the stress relaxation rate is 10%. It is as follows.
[0015]
The 1st aspect of the manufacturing method of the copper base alloy strip for terminals of this invention is weight%, Ni: 0.2-3.0%, Sn: 2.0% or less, P: 0.005-2. A first step of continuously casting a copper base alloy containing 0% and the balance being Cu and inevitable impurities, a second step of homogenizing annealing at a heat treatment temperature of 500 to 950 ° C. in a non-oxidizing atmosphere, After the intermediate rolling, the intermediate annealing is performed one or more times at an annealing temperature of 450 to 650 ° C. in a non-oxidizing atmosphere, and the rolling ratio before the final intermediate annealing is 85% or more, and the rolling ratio is 30. It consists of a fourth step of finish cold rolling as ˜90% and a fifth step of low temperature annealing at an annealing temperature of 250 to 400 ° C.
[0016]
The intermediate annealed product obtained in the third step has a recrystallized grain size of 5 μm or less, and a part of Ni and P becomes a Ni-P intermetallic compound of 20 nm or less and precipitates uniformly and finely in the matrix. Have an organization.
[0017]
The 2nd aspect of the manufacturing method of the copper base alloy strip for terminals of this invention is weight%, Mn: 0.2-3.0%, Sn: 2.0% or less, P: 0.005-2. A first step of continuously casting a copper base alloy containing 0% and the balance being Cu and inevitable impurities, a second step of homogenizing annealing at a heat treatment temperature of 500 to 950 ° C. in a non-oxidizing atmosphere, After the intermediate rolling, the intermediate annealing is performed one or more times at an annealing temperature of 450 to 650 ° C. in a non-oxidizing atmosphere, and the rolling ratio before the final intermediate annealing is 85% or more, and the rolling ratio is 30. It consists of a fourth step of finish cold rolling as ˜90% and a fifth step of low temperature annealing at an annealing temperature of 250 to 400 ° C.
[0018]
The intermediate annealed product obtained in the third step has a recrystallized grain size of 5 μm or less, and a part of Mn and P becomes a Mn-P intermetallic compound of 20 nm or less and precipitates uniformly and finely in the matrix. Have an organization.
[0019]
The third aspect of the method for producing a copper-based alloy strip for terminals of the present invention is, by weight, Co: 0.1 to 1.0%, Sn: 2.0% or less, P: 0.005 to 1. A first step of continuously casting a copper base alloy containing 0% and the balance being Cu and inevitable impurities, a second step of homogenizing annealing at a heat treatment temperature of 500 to 980 ° C. in a non-oxidizing atmosphere, After the intermediate rolling, the intermediate annealing is performed one or more times at an annealing temperature of 450 to 650 ° C. in a non-oxidizing atmosphere, and the rolling ratio before the final intermediate annealing is 85% or more, and the rolling ratio is 30. It consists of a fourth step of finish cold rolling as ˜90% and a fifth step of low temperature annealing at an annealing temperature of 300 to 450 ° C.
[0020]
The intermediate annealed product obtained in the third step has a recrystallized grain size of 5 μm or less, and a part of Co and P becomes a Co—P intermetallic compound of 20 nm or less and precipitates uniformly and finely in the matrix. Have an organization.
[0021]
The copper-based alloy strips for terminals according to the first to third aspects are each manufactured by the manufacturing method according to the first to third aspects.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
(1) Alloy element The additive element in the copper-based alloy of the present invention and the additive element in melting the copper-based alloy ingot in the first step of the method for producing the copper-based alloy strip of the present invention are Has an effect.
[0023]
(A) Ni, Mn, Co
Ni (or Mn, Co) dissolves in the Cu matrix to improve strength / spring characteristics and stress relaxation resistance. The coexisting P and the formed Ni—P intermetallic compound (Ni ₃ P) (or Mn—P intermetallic compound (Mn ₃ P), Co—P intermetallic compound (Co ₂ P)) It is dispersed and deposited uniformly and finely in the matrix to improve conductivity and further improve strength, spring characteristics and stress relaxation resistance.
[0024]
The effect of Ni (or Mn, Co) cannot be sufficiently obtained when Ni and Mn are less than 0.2% by weight and Co is less than 0.1% by weight, and Ni and Mn are 3.0% by weight, If Co exceeds 1.0% by weight, it will be saturated. Therefore, Ni and Mn are desirably 0.2% by weight or more and 3.0% by weight or less, and Co is desirably 0.1% by weight or more and 1.0% by weight or less.
[0025]
(B) Sn
Sn is dissolved in the Cu matrix to improve strength and spring characteristics.
[0026]
The effect of Sn is saturated when the Sn component exceeds 2.0% by weight. Therefore, the Sn component is desirably 2.0% by weight or less.
[0027]
(C) P
P is not only solid-solved in the Cu matrix but also dispersed and precipitated Ni—P intermetallic compound (Ni ₃ P) (or Mn—P intermetallic compound (Mn ₃ P), Co—P system It is formed with Ni (or Mn, Co) in which an intermetallic compound (Co ₂ P)) coexists. Thereby, strength, conductivity, spring characteristics, and stress relaxation resistance are improved.
[0028]
The effect of the P cannot be sufficiently obtained when the P component is less than 0.005% by weight, and the P component is 2.0% by weight in the case of Cu—Ni (Mn) —Sn—P alloy, Cu—Co. In the case of -Sn-P alloy, when it exceeds 1.0% by weight, it is saturated. Therefore, the P component needs to be 0.005% by weight or more, 2.0% by weight or less for Cu—Ni (Mn) —Sn—P alloy, 1.0% by weight for Cu—Co—Sn—P alloy. The following is desirable.
[0029]
(2) Homogenization annealing Homogenization annealing is performed to eliminate segregation of solid solution elements and to sufficiently dissolve Ni (or Mn, Co) and P. From this solid solution state, aging precipitation is performed as a Ni ₃ P compound (or Mn ₃ P compound or Co ₂ P compound) in a subsequent step. When the heat treatment temperature is less than 500 ° C., the temperature is low, segregation of elements cannot be sufficiently removed, and a single phase (supersaturated solid solution) in which Ni (or Mn, Co) and P are dissolved is not formed. On the other hand, when the temperature is higher than 950 ° C. for the Cu—Ni (Mn) —Sn—P alloy and higher than 980 ° C. for the Cu—Co—Sn—P alloy, the temperature is close to the melting point and the bending workability is sufficiently high It becomes impossible to improve. This is because the crystal grain size becomes coarse and the recrystallized grain size (used for finish rolling) in the subsequent cold rolling and intermediate annealing cannot be adjusted to 5 μm or less.
[0030]
Moreover, the reason why the homogenization annealing treatment is performed in a non-oxidizing atmosphere is to suppress oxidation and internal oxidation of the material surface.
[0031]
At this time, in order to obtain a single-phase (supersaturated) structure at room temperature, the homogenized and annealed ingot is rapidly cooled. This rapid cooling may be performed by water cooling, air cooling, oil cooling or the like that is usually performed.
[0032]
(3) Cold rolling and intermediate annealing The coil obtained by the above rapid cooling is subjected to intermediate annealing at an annealing temperature of 450 to 650 ° C after cold rolling. This cold rolling / intermediate annealing may be performed once, but may be performed a plurality of times in order to perform cold rolling efficiently. In the case of finishing once, after cold rolling with a rolling rate of 85% or more, intermediate annealing is performed at an annealing temperature of 450 to 650 ° C. In the case of performing a plurality of times, cold rolling is performed, and then an annealing temperature is set to 450 to 650 ° C., followed by intermediate annealing, and then a series of operations for cold rolling and intermediate annealing are repeated. The previous cold rolling rate must be 85% or more. The reason why the rolling rate of the cold rolling rate is set to 85% or more is to make the recrystallized grain size 5 μm or less. The particle size of the Ni ₃ P compound (or Mn ₃ P compound or Co ₂ P compound) that is aging-precipitated is as fine as 20 nm or less, although it depends on the composition of Ni (or Mn, Co) and P. If recrystallization does not proceed sufficiently in cold rolling and intermediate annealing, or if the recrystallized grain size exceeds 5 μm, it becomes impossible to sufficiently improve the bending workability.
[0033]
When the rolling rate is less than 85%, it is difficult to adjust the recrystallized grain size to be used for the finish rolling in the subsequent process to 5 μm or less. Further, if the intermediate annealing temperature is less than 450 ° C., the recrystallization does not proceed sufficiently. On the other hand, if the temperature exceeds 650 ° C., the recrystallized grain size becomes coarser than 5 μm.
[0034]
(4) Finish cold rolling The rolling rate of finish cold rolling is 30 to 90%. If it is less than 30%, the strength and stress relaxation resistance are lowered, whereas if it exceeds 90%, bending workability is lowered.
[0035]
(5) To sufficiently precipitate low-temperature annealed Ni ₃ P compound (or Mn ₃ P compound, Co ₂ P compound), and at the same time, remove strain without proceeding recrystallization to give sufficient bending workability To do. Therefore, the low-temperature annealing temperature is set to 250 to 400 ° C. for the Cu—Ni (Mn) —Sn—P based alloy and 300 to 450 ° C. for the Cu—Co—Sn—P based alloy. If it is less than this minimum temperature, the said reaction does not occur and bending workability falls. On the other hand, when the temperature exceeds the maximum temperature, the strain can be removed but the recrystallization proceeds and the strength and stress relaxation resistance are lowered.
[0036]
(6) Measurement of characteristics The tensile strength, conductivity, and spring limit value were measured in accordance with JISH2241, JISH0505, and JISH3130. The bending workability was evaluated by a 90 ° W bending work test. The test was performed according to CES-M0002-6, 90 ° W bending was performed with a jig having a bending radius of 0.1 to 2.0, and the state of the central mountain surface was examined. The bending axis was a direction parallel to the rolling direction (Bad Way). Then, a value obtained by dividing the minimum bending radius R at which cracks and wrinkles do not occur by the thickness t, that is, the minimum bending radius ratio R / t was obtained. The smaller the minimum bending radius ratio, the better the bending workability. In the stress relaxation test, arch bending is performed so that the stress at the center of the test piece becomes 80% of the proof stress, and the specimen is held at a temperature of 150 ° C. for 1000 hours. Calculated. In the following equation, L ₀ is the length of the jig (mm), L ₁ is the horizontal distance (mm) between the sample ends before bending, and L ₂ is between the sample ends after bending. Horizontal distance (mm).
[0037]
Stress relaxation rate (%) = (L ₁ −L ₂ ) / (L ₁ −L ₀ ) × 100
[0038]
(Example)
The present invention will be described below with reference to Examples 1 and 2, Comparative Examples 1 to 7, and Conventional Examples 1 and 2. The alloy compositions in these examples, comparative examples, and conventional examples are shown in Table 1, and the main production conditions are also shown.
[0039]
(Examples 1 and 2)
(1) Melting and continuous casting of alloy ingots Alloys having the compositions shown in Examples 1 and 2 in Table 1 were cast to a thickness of 17 mm and a width of 600 mm, respectively, by the horizontal continuous casting method. Both sides were cut by 1 mm.
[0040]
(2) The homogenized annealed alloy ingot was homogenized and annealed at 850 ° C. for 2 hours in a non-oxidizing atmosphere, and then air-cooled.
[0041]
(3) Cold rolling / intermediate annealing The air-cooled homogenized annealing product was cold-rolled to form a 0.63 mm thick plate (rolling rate 96%), and this plate was subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the examples, and the Ni—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less. .
[0042]
(4) Cold rolling with a rolling reduction rate of 60% was performed on the plate material that was subjected to finish cold rolling continuous annealing.
[0043]
(5) Low-temperature annealing Low-temperature annealing treatment at 350 ° C. was run at 10 m / min in a nitrogen atmosphere in this continuous annealing furnace, and cooling water was injected onto the plate material coming out of the furnace.
[0044]
(Comparative Examples 1 and 2)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 1 and 2 in Table 1 were produced in the same manner as in Example 1.
[0045]
(2) The homogenized annealing alloy ingot was subjected to homogenization annealing at 450 ° C. for 5 hours and Comparative Example 2 at 980 ° C. for 2 hours in a non-oxidizing atmosphere, and then air-cooled.
[0046]
(3) Cold rolling / intermediate annealing. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in Comparative Example 1 and 15 μm in Comparative Example 2. Further, the Ni—P intermetallic compound was non-uniformly deposited with a size of 1 μm or less in Comparative Example 1, and was uniformly and finely deposited with a size of 20 nm or less in Comparative Example 2.
[0047]
(4) Finish cold rolling: performed in the same manner as in Example 1.
[0048]
(5) Low temperature annealing: performed in the same manner as in Example 1.
[0049]
(Comparative Example 3)
(1) Melting and continuous casting of alloy ingot: The alloy shown in Comparative Example 3 in Table 1 was produced in the same manner as in Example 1.
[0050]
(2) Homogenization annealing: The same as in Example 1.
[0051]
(3) Cold Rolling / Intermediate Annealing Air-cooled homogenized annealed product was cold rolled to a rolling rate of 78% to form a plate material having a thickness of 3.0 mm, and this plate was subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. Next, this continuous annealed product was cold rolled again at a rolling rate of 78% to form a plate material having a thickness of 0.65 mm, and the same continuous annealing treatment was performed. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 10 μm, and the Ni—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less.
[0052]
(4) Finish cold rolling: performed in the same manner as in Example 1.
[0053]
(5) Low temperature annealing: performed in the same manner as in Example 1.
[0054]
(Comparative Examples 4 and 5)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 4 and 5 in Table 1 were produced in the same manner as in Example 1.
[0055]
(2) Homogenization annealing: The same as in Example 1.
[0056]
(3) Cold rolling / intermediate annealing The air-cooled homogenized annealing product was cold-rolled to form a 0.63 mm thick plate (rolling rate 96%), and this plate was subjected to a continuous annealing treatment. In the continuous annealing treatment, the plate material was run at 8 m / min in a heating furnace maintained at 400 ° C. in Comparative Example 4 at 700 ° C. in Comparative Example 4 at 700 ° C., and cooling water was injected onto the plate material coming out of the furnace I went there. The recrystallized structure of the plate material (alloy strip) obtained by this continuous annealing was a partial recrystallized structure in Comparative Example 4, and was completely recrystallized with a crystal grain size of 10 μm in Comparative Example 5. Further, the Ni—P intermetallic compound was not precipitated in Comparative Example 4, and was uniformly precipitated in a size of 50 nm or less in Comparative Example 5.
[0057]
(4) Finish cold rolling: performed in the same manner as in Example 1.
[0058]
(5) Low temperature annealing: performed in the same manner as in Example 1.
[0059]
(Comparative Examples 6 and 7)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 6 and 7 in Table 1 were produced in the same manner as in Example 1.
[0060]
(2) Homogenization annealing: The same as in Example 1.
[0061]
(3) Cold rolling / intermediate annealing. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the comparative examples, and the Ni—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less. .
[0062]
(4) Finish cold rolling: performed in the same manner as in Example 1.
[0063]
(5) Low-temperature annealing In this continuous annealing furnace, in a nitrogen atmosphere, Comparative Example 6 runs a low-temperature annealing treatment at 230 ° C., and Comparative Example 7 runs a low-temperature annealing treatment at 430 ° C. at 10 m / min. The cooling water was jetted onto the plate material.
[0064]
(Conventional examples 1 and 2)
Alloys having the compositions shown in Conventional Examples 1 and 2 in Table 1 were melted in an atmospheric melting furnace. Next, the alloy ingot was heated at 850 ° C., hot-rolled to a thickness of 17 mm, and then immersed in water at room temperature to be rapidly cooled. The surface of the quenched hot-rolled product was chamfered to a thickness of 15 mm, and then cold-rolled to form a plate material having a thickness of 0.63 mm, and subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the conventional examples, and the Ni—P intermetallic compound was deposited in a non-uniform manner with a size of 50 nm or less. . Next, this continuously annealed plate material is subjected to cold rolling with a rolling rate of 60%, and a low temperature annealing treatment at 350 ° C. is run at 10 m / min in a nitrogen atmosphere in a continuous annealing furnace, and the plate material coming out of the furnace is The cooling water was injected.
[0065]
The plate materials (alloy strips) thus obtained were measured for tensile strength, electrical conductivity, and spring limit values, and examined for bending workability and stress relaxation properties. The results are shown in Table 2.
[0066]
[Table 1]

[0067]
[Table 2]

[0068]
The present invention will be described below with reference to Examples 3 and 4, Comparative Examples 8 to 14, and Conventional Examples 3 and 4. The alloy compositions in these examples, comparative examples, and conventional examples are shown in Table 3, and the main production conditions are also shown.
[0069]
(Examples 3 and 4)
(1) Melting and continuous casting of alloy ingots Alloys having the compositions shown in Examples 3 and 4 of Table 3 were cast to a thickness of 15 mm and a width of 600 mm, respectively, by the horizontal continuous casting method. Both sides were cut by 1 mm.
[0070]
(2) The homogenized annealed alloy ingot was homogenized and annealed at 850 ° C. for 2 hours in a non-oxidizing atmosphere, and then air-cooled.
[0071]
(3) Cold rolling / intermediate annealing The air-cooled homogenized annealing product was cold-rolled to form a 0.63 mm thick plate (rolling rate 96%), and this plate was subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the examples, and the Mn—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less. .
[0072]
(4) Cold rolling with a rolling reduction rate of 60% was performed on the plate material that was subjected to finish cold rolling continuous annealing.
[0073]
(5) Low-temperature annealing Low-temperature annealing treatment at 350 ° C. was run at 10 m / min in a nitrogen atmosphere in this continuous annealing furnace, and cooling water was injected onto the plate material coming out of the furnace.
[0074]
(Comparative Examples 8 and 9)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 8 and 9 in Table 3 were performed in the same manner as in Example 3.
[0075]
(2) In a non-oxidizing atmosphere, the homogenized annealing alloy ingot was subjected to homogenization annealing at 450 ° C. for 5 hours and Comparative Example 9 at 980 ° C. for 2 hours, and then air-cooled.
[0076]
(3) Cold rolling / intermediate annealing. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in Comparative Example 8 and 15 μm in Comparative Example 9. Further, the Mn—P intermetallic compound was non-uniformly deposited with a size of 1 μm or less in Comparative Example 8, and was uniformly and finely deposited with a size of 20 nm or less in Comparative Example 9.
[0077]
(4) Finish cold rolling: performed in the same manner as in Example 3.
[0078]
(5) Low temperature annealing: performed in the same manner as in Example 3.
[0079]
(Comparative Example 10)
(1) Melting and continuous casting of alloy ingot: The alloy shown in Comparative Example 10 in Table 3 was prepared in the same manner as in Example 3.
[0080]
(2) Homogenization annealing: The same as in Example 3.
[0081]
(3) Cold Rolling / Intermediate Annealing Air-cooled homogenized annealed product was cold rolled to a rolling rate of 78% to form a plate material having a thickness of 3.0 mm, and this plate was subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. Next, this continuously annealed plate material was cold rolled again to a rolling rate of 78% to obtain a 0.65 mm thick plate material, and subjected to the same continuous annealing treatment. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 10 μm, and the Mn—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less.
[0082]
(4) Finish cold rolling: performed in the same manner as in Example 3.
[0083]
(5) Low temperature annealing: performed in the same manner as in Example 3.
[0084]
(Comparative Examples 11 and 12)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 11 and 12 in Table 3 were performed in the same manner as in Example 3.
[0085]
(2) Homogenization annealing: The same as in Example 3.
[0086]
(3) Cold rolling / intermediate annealing The air-cooled homogenized annealing product was cold-rolled to form a 0.63 mm thick plate (rolling rate 96%), and this plate was subjected to a continuous annealing treatment. In the continuous annealing treatment, the plate material was run in a heating furnace maintained at 400 ° C. in Comparative Example 11 at 700 ° C. and at 700 ° C. in Comparative Example 12 at 8 m / min, and cooling water was injected onto the plate material coming out of the furnace I went there. The recrystallized structure of the plate material (alloy strip) obtained by this continuous annealing was a partially recrystallized structure in Comparative Example 11, and was completely recrystallized with a crystal grain size of 10 μm in Comparative Example 12. In addition, the Mn—P intermetallic compound was not precipitated in Comparative Example 11, but was uniformly precipitated with a size of 50 nm or less in Comparative Example 12.
[0087]
(4) Finish cold rolling: performed in the same manner as in Example 3.
[0088]
(5) Low temperature annealing: performed in the same manner as in Example 3.
[0089]
(Comparative Examples 13 and 14)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 13 and 14 in Table 3 were performed in the same manner as in Example 3.
[0090]
(2) Homogenization annealing: The same as in Example 3.
[0091]
(3) Cold rolling / intermediate annealing. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the comparative examples, and the Mn—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less. .
[0092]
(4) Finish cold rolling: performed in the same manner as in Example 3.
[0093]
(5) Low-temperature annealing In a nitrogen atmosphere in this continuous annealing furnace, Comparative Example 13 runs a low-temperature annealing treatment at 230 ° C., and Comparative Example 14 runs a low-temperature annealing treatment at 430 ° C. at 10 m / min and comes out of the furnace. The cooling water was jetted onto the plate material.
[0094]
(Conventional examples 3 and 4)
Alloys having the compositions shown in Conventional Examples 3 and 4 in Table 3 were melted in an atmospheric melting furnace. Next, this alloy ingot was heated at 850 ° C., hot-rolled to a thickness of 15 mm, and then immersed in water at room temperature to be rapidly cooled. The surface of the rapidly cooled hot-rolled product was chamfered to a thickness of 13 mm, and then cold-rolled to form a plate material having a thickness of 0.63 mm, followed by continuous annealing. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any conventional example, and the Mn—P intermetallic compound was deposited nonuniformly in a size of 50 nm or less. . Next, this continuously annealed plate material is subjected to cold rolling with a rolling rate of 60%, and a low temperature annealing treatment at 350 ° C. is run at 10 m / min in a nitrogen atmosphere in a continuous annealing furnace, and the plate material coming out of the furnace is The cooling water was injected.
[0095]
The plate materials (alloy strips) thus obtained were measured for tensile strength, electrical conductivity, and spring limit values, and examined for bending workability and stress relaxation properties. The results are shown in Table 4.
[0096]
[Table 3]

[0097]
[Table 4]

[0098]
The present invention will be described below with reference to Examples 5 and 6, Comparative Examples 15 to 21, and Conventional Examples 5 and 6. The alloy compositions in these examples, comparative examples, and conventional examples are shown in Table 5, and the main production conditions are also shown.
[0099]
(Examples 5 and 6)
(1) Melting and continuous casting of alloy ingots Alloys having the compositions shown in Examples 5 and 6 of Table 5 were cast to a thickness of 15 mm and a width of 600 mm, respectively, by the horizontal continuous casting method. Both sides were cut by 1 mm.
[0100]
(2) The homogenized annealing alloy ingot was homogenized and annealed at 950 ° C. for 2 hours in a non-oxidizing atmosphere, and then air-cooled.
[0101]
(3) Cold rolling / intermediate annealing The air-cooled homogenized annealing product was cold-rolled to form a 0.63 mm thick plate (rolling rate 96%), and this plate was subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the examples, and the Co—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less. .
[0102]
(4) Cold rolling with a rolling reduction rate of 60% was performed on the plate material that was subjected to finish cold rolling continuous annealing.
[0103]
(5) Low-temperature annealing A low-temperature annealing treatment at 400 ° C. was run at 10 m / min in a nitrogen atmosphere in this continuous annealing furnace, and cooling water was injected onto the plate material coming out of the furnace.
[0104]
(Comparative Examples 15 and 16)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 15 and 16 in Table 5 were performed in the same manner as in Example 5.
[0105]
(2) The homogenized annealing alloy ingot was subjected to homogenization annealing at 450 ° C. for 5 hours and Comparative Example 16 at 1000 ° C. for 2 hours in a non-oxidizing atmosphere, and then air-cooled.
[0106]
(3) Cold rolling / intermediate annealing. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in Comparative Example 15 and 15 μm in Comparative Example 16. Further, the Co—P intermetallic compound was deposited nonuniformly in a size of 1 μm or less in Comparative Example 15, and was uniformly finely deposited in a size of 20 nm or less in Comparative Example 16.
[0107]
(4) Finish cold rolling: performed in the same manner as in Example 5.
[0108]
(5) Low temperature annealing: performed in the same manner as in Example 5.
[0109]
(Comparative Example 17)
(1) Melting and continuous casting of alloy ingot: The alloy shown in Comparative Example 17 in Table 5 was prepared in the same manner as in Example 5.
[0110]
(2) Homogenization annealing: The same as in Example 5.
[0111]
(3) Cold Rolling / Intermediate Annealing Air-cooled homogenized annealed product was cold rolled to a rolling rate of 78% to form a plate material having a thickness of 3.0 mm, and this plate was subjected to a continuous annealing treatment. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. Next, this continuously annealed plate material was cold rolled again to a rolling rate of 78% to obtain a 0.65 mm thick plate material, and subjected to the same continuous annealing treatment. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 10 μm, and the Co—P intermetallic compound was precipitated in a uniform fine manner with a size of 20 nm or less.
[0112]
(4) Finish cold rolling: performed in the same manner as in Example 5.
[0113]
(5) Low temperature annealing: performed in the same manner as in Example 5.
[0114]
(Comparative Examples 18 and 19)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 18 and 19 in Table 5 were performed in the same manner as in Example 5.
[0115]
(2) Homogenization annealing: The same as in Example 5.
[0116]
(3) Cold rolling / intermediate annealing The air-cooled homogenized annealing product was cold-rolled to form a 0.63 mm thick plate (rolling rate 96%), and this plate was subjected to a continuous annealing treatment. In the continuous annealing treatment, the plate material was run at 8 m / min in a heating furnace maintained at 400 ° C. in Comparative Example 18 and 700 ° C. in Comparative Example 18 in a nitrogen atmosphere, and cooling water was jetted onto the plate material coming out of the furnace. I went there. The recrystallized structure of the plate material (alloy strip) obtained by this continuous annealing was a partial recrystallized structure in Comparative Example 18, and a complete recrystallization with a crystal grain size of 10 μm in Comparative Example 19. In addition, the Co—P intermetallic compound was not precipitated in Comparative Example 18, but was uniformly precipitated with a size of 500 nm or less in Comparative Example 19.
[0117]
(4) Finish cold rolling: performed in the same manner as in Example 5.
[0118]
(5) Low temperature annealing: performed in the same manner as in Example 5.
[0119]
(Comparative Examples 20 and 21)
(1) Melting and continuous casting of alloy ingot: The alloys shown in Comparative Examples 20 and 21 in Table 5 were performed in the same manner as in Example 5.
[0120]
(2) Homogenization annealing: The same as in Example 5.
[0121]
(3) Cold rolling / intermediate annealing. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the comparative examples, and the Co—P intermetallic compound was uniformly and finely precipitated with a size of 20 nm or less. .
[0122]
(4) Finish cold rolling: performed in the same manner as in Example 5.
[0123]
(5) Low-temperature annealing In a nitrogen atmosphere in this continuous annealing furnace, Comparative Example 20 runs a low-temperature annealing treatment at 280 ° C., and Comparative Example 21 runs a low-temperature annealing treatment at 480 ° C. at 10 m / min and comes out of the furnace. The cooling water was jetted onto the plate material.
[0124]
(Conventional examples 5 and 6)
Alloys having the compositions shown in Conventional Examples 5 and 6 in Table 5 were melted in an atmospheric melting furnace. Next, this alloy ingot was heated at 950 ° C., hot-rolled to a thickness of 15 mm, and then immersed in water at room temperature to be rapidly cooled. The surface of the rapidly cooled hot-rolled product was chamfered to a thickness of 13 mm, and then cold-rolled to form a plate material having a thickness of 0.63 mm, followed by continuous annealing. The continuous annealing treatment was performed by running the plate material at 8 m / min in a heating furnace maintained at 600 ° C. in a nitrogen atmosphere, and injecting cooling water onto the plate material coming out of the furnace. The recrystallized grain size of the plate material (alloy strip) obtained by this continuous annealing was 3 μm in any of the conventional examples, and the Co—P intermetallic compound was deposited nonuniformly in a size of 50 nm or less. . Next, this continuously annealed plate material is subjected to cold rolling at a rolling rate of 60%, and a low temperature annealing process at 400 ° C. is run at 10 m / min in a nitrogen atmosphere in a continuous annealing furnace, and the plate material coming out of the furnace is The cooling water was injected.
[0125]
The materials thus obtained were measured for tensile strength, electrical conductivity, and spring limit values, and examined for bending workability and stress relaxation properties. The results are shown in Table 6.
[0126]
[Table 5]

[0127]
[Table 6]

[0128]
【The invention's effect】
The method of the present invention eliminates the hot rolling step that causes problems such as generation of surface oxide scale and precipitation of coarse intermetallic compounds during material production, and has excellent characteristics for a copper-based alloy strip for terminals and a method for producing the same Therefore, it is possible to improve the yield and reduce the production cost without requiring energy for heating the material at the time of hot rolling to a high temperature and the accompanying capital investment.

Claims

Copper-based alloy containing Ni: 0.2-3.0%, Sn: 2.0% or less, P: 0.005-2.0% with the balance being Cu and inevitable impurities The first step of continuous casting, the second step of homogenizing annealing at a heat treatment temperature of 500 to 950 ° C. in a non-oxidizing atmosphere, and the intermediate annealing temperature of 450 to 650 ° C. in a non-oxidizing atmosphere after cold rolling Annealing is performed at least once, the third step of making the rolling rate before the final intermediate annealing 85% or more, the fourth step of finish cold rolling with the rolling rate of 30 to 90%, and the annealing temperature of 250 to A method for producing a copper-based alloy strip for terminals comprising a fifth step of low-temperature annealing at 400 ° C.

The method for producing a copper-based alloy strip for terminals according to claim 1 , wherein the intermediate annealed product obtained in the third step has a recrystallized grain size of 5 µm or less.

The terminal according to claim 1 , wherein the intermediate annealed product obtained in the third step has a structure in which a part of Ni and P becomes a Ni-P intermetallic compound having a thickness of 20 nm or less and is uniformly and finely precipitated in the matrix. Manufacturing method for copper-based alloy.

Copper based alloy containing, by weight%, Mn: 0.2 to 3.0%, Sn: 2.0% or less, P: 0.005 to 2.0% , the balance being Cu and inevitable impurities The first step of continuous casting, the second step of homogenizing annealing at a heat treatment temperature of 500 to 950 ° C. in a non-oxidizing atmosphere, and the intermediate annealing temperature of 450 to 650 ° C. in a non-oxidizing atmosphere after cold rolling Annealing is performed at least once, the third step of making the rolling rate before the final intermediate annealing 85% or more, the fourth step of finish cold rolling with the rolling rate of 30 to 90%, and the annealing temperature of 250 to A method for producing a copper-based alloy strip for terminals comprising a fifth step of low-temperature annealing at 400 ° C.

The method for producing a copper-based alloy strip for a terminal according to claim 4 , wherein the intermediate annealed product obtained in the third step has a recrystallized grain size of 5 µm or less.

The terminal according to claim 4 , wherein the intermediate annealed product obtained in the third step has a structure in which a part of Mn and P becomes a Mn-P intermetallic compound having a size of 20 nm or less and is uniformly and finely precipitated in the matrix. For producing copper-based alloy strips.

Copper-based alloy containing Co: 0.1 to 1.0%, Sn: 2.0% or less, P: 0.005 to 1.0%, the balance being Cu and inevitable impurities The first step of continuous casting, the second step of homogenizing annealing at a heat treatment temperature of 500 to 980 ° C. in a non-oxidizing atmosphere, and the intermediate temperature of 450 to 650 ° C. in the non-oxidizing atmosphere after cold rolling Annealing is performed at least once, the third step for setting the rolling rate before the final intermediate annealing to 85% or more, the fourth step for finish cold rolling at a rolling rate of 30 to 90%, and the annealing temperature for 300 to 300%. The manufacturing method of the copper base alloy strip for terminals which consists of the 5th process annealed at 450 degreeC low temperature.

The method for producing a copper-based alloy strip for a terminal according to claim 7 , wherein the intermediate annealed product obtained in the third step has a recrystallized grain size of 5 µm or less.

The terminal according to claim 7 , wherein the intermediate annealed product obtained in the third step has a structure in which a part of Co and P becomes a Co—P intermetallic compound having a thickness of 20 nm or less and is uniformly and finely precipitated in the matrix. For producing copper-based alloy strips.