JP4527898B2 - High corrosion resistance plated stranded steel wire and method for producing the same - Google Patents
High corrosion resistance plated stranded steel wire and method for producing the same Download PDFInfo
- Publication number
- JP4527898B2 JP4527898B2 JP2001111879A JP2001111879A JP4527898B2 JP 4527898 B2 JP4527898 B2 JP 4527898B2 JP 2001111879 A JP2001111879 A JP 2001111879A JP 2001111879 A JP2001111879 A JP 2001111879A JP 4527898 B2 JP4527898 B2 JP 4527898B2
- Authority
- JP
- Japan
- Prior art keywords
- wire
- steel wire
- stranded
- plated
- high corrosion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Landscapes
- Metal Extraction Processes (AREA)
- Coating With Molten Metal (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、熱間圧延された線材を伸線加工によって、より細い線径に加工し、これらを複数本を撚って製造される、溶融亜鉛めっき線、ロープ、ＡＣＳＲ線、ＰＣ鋼撚り線などの撚り鋼線に関するものである。
【０００２】
【従来の技術】
ＰＣ鋼線は、通常、ＪＩＳ Ｇ３５０２に規定されるピアノ線材にパテンティングを行った後伸線し、その後３００〜４００℃の温度範囲でホットストレッチングを施す方法で製造されている。
ＰＣ鋼線は、その使用環境であるコンクリートがアルカリ環境であるため、従来、耐食性に関してはほとんど問題にされてなかった。しかし、近年、コンクリートの骨材である川砂や山砂が不足し、代わって海砂が使用されるようになってきたため、ＰＣ鋼線にも耐食性が要求される場合が増加しつつある。また、ＰＣ撚り線そのものがコンクリートの中ではなく外ケーブルとして使用される場合が増加し耐食性の向上が期待されている。
【０００３】
このため、特開昭５９−１７９７５５号公報には鋼組成を制御すること、具体的にはＣｕ，Ｎｉ，Ｗを添加し、Ｓｉ含有量を低減することにより、塩分環境におけるＰＣ鋼線の腐食を抑制することが記載されている。しかし、Ｓｉ含有量を低く抑えることは、ＰＣ鋼線の高強度化およびリラクゼーション値の低下と反することになる。
【０００４】
一方、ＰＣ鋼線にめっき等の被覆を施すことはあまり行われていない。これは、溶融Ｚｎめっきを行った場合、鋼線温度は約４５０℃に昇温し、リラクセーション値が増加するためである。また、溶融Ｚｎめっき後伸線する方法（いわゆるアフタードロー）は強度特性上は好ましいが、溶融Ｚｎめっき鋼線のＺｎ−Ｆｅ合金層は脆いため伸線中にめっき層にクラックが発生する。また、伸線加工されたＺｎ層は伸線加工により相対的に厚みが薄くなるので、十分な耐食性を兼ね備えるためには伸線前に厚めっきする必要がある。しかし、めっき厚みが厚くなると伸線加工が著しく難しくなる問題点がある。
【０００５】
一方、鋼線の耐食性を向上させるために、従来のＺｎめっきに代わり、各種のＺｎ−Ａｌ合金めっきが開発されている。例えば、特公昭５５−２６７０２号公報にはＺｎ−Ａｌ、特公昭５４−３３２２３号公報にはＺｎ−Ａｌ−Ｍｇ、特開昭５７−５００４７５号公報には、Ｚｎ−Ａｌ−ミッシュメタル、特開昭５６−１１２４５２号公報にはＺｎ−Ａｌ−Ｎａなどが記載されている。これらは、いずれも従来の溶融Ｚｎめっき法と同様、溶融状態（約４５０℃）の合金めっき浴中に鋼線を浸漬する方法でめっきするため、上記の溶融Ｚｎめっきと同様の問題が存在する。電気亜鉛めっき方はコスト高となり、また、水素の侵入による遅れ破壊の危険があるため実施されていない。
【０００６】
【発明が解決しようとする課題】
このように、従来の技術では耐食性に優れた高耐食性めっき撚り鋼線を製造することは不可能であった。本発明の目的は、上記従来法の問題点を解決し、従来より高強度かつ高耐食性を備えためっき撚り鋼線とその製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
本発明は、上記課題を解決するためになされたもので、その要旨は次のとおりである。
（１）鋼線からなる撚り線であって、より線の表面のうち１本１本の素線の向かいあった部分がＺｎめっきであって、その外側に位置して前記向かいあった部分以外の前記表面にＺｎを主成分とする合金めっきが施されていることを特徴とする高耐食性めっき撚り鋼線。
（２）鋼線よりなる撚り線であって、撚り線の中心に芯線あるい-は芯となる撚り線が存在し、その外側に存在する素線の表面のうち前記芯線あるいは芯となる撚り線と向かいあった部分がＺｎめっきであって、その外側に位置して前記向かいあった部分以外の前記表面にＺｎを主成分とする合金めっきが施されていることを特徴とする高耐食性めっき撚り鋼線。
（３）前記Ｚｎを主成分とする合金めっきがＡｌを０．１〜２０％含むＺｎ合金であることを特徴とする請求項１または２記載の高耐食性めっき撚り鋼線。
（４）前記Ｚｎを主成分とする合金めっき層の外側に、有機被膜塗装、無機被膜塗装、有機物被覆のいずれか１つ以上を施したことを特徴とする請求項１〜３の高耐食性めっき撚り鋼線。
（５）前記鋼線が、質量％で、
Ｃ：０．４〜１．３％、
Ｓｉ：０．１〜２．０％、
Ｍｎ：０．１〜２．０％、
を含有する鋼線を用いることを特徴とする請求項１または２記載の高耐食性めっき撚り鋼線。
（６）前記鋼線が、質量％で、さらに、Ｃｒ：０．０５〜１．５％，Ｎｉ：０．０５〜１．５％，Ｖ：０．００５〜１．０％，Ｎｂ：０．００５〜１．０％，Ｍｏ：０．００５〜１．０％の一種以上を添加することを特徴とする請求項５記載の高耐食性めっき撚り鋼線。
（７）前記鋼線が、質量％で、さらに、Ｃｕ：０．０５〜１．５％を添加することを特徴とする請求項５または６記載の高耐食性めっき撚り鋼線。
（８）前記鋼線が、重量％で、さらに、Ａｌ：０．００１〜０．１％，Ｂ：０．０００５〜０．１％を添加することを特徴とする請求項５〜７のいずれかの項に記載の高耐食性めっき撚り鋼線。
（９）前記鋼線が、重量％で、さらに、Ｐ：０．０２％以下、Ｓ：０．０２％以下を添加することを特徴とする請求項５〜８のいずれかの項に記載の高耐食性めっき撚り鋼線。
（１０）請求項５〜９のいずれかの項に記載の高耐食性めっき撚り鋼線の製造方法であって、請求項５〜９のいずれかに記載の鋼組成を有するＺｎめっきされた線材に、伸線加工してより細い径のワイヤとし、その何本かを組み合わせて撚り合わせた後、１％以上７％以下のストレッチングを行い、さらにＺｎを主成分とする合金めっきを施すことにより請求項１または２記載のめっき撚り線とすることを特徴とする高耐食性めっき撚り鋼線の製造方法。
（１１）請求項５〜９のいずれかの項に記載の高耐食性めっき撚り鋼線の製造方法であって、請求項５〜９のいずれかに記載の鋼組成を有するＺｎめっきされた線材に、伸線加工してより細い径のワイヤとし、その何本かを組み合わせ撚り合わせた後、１％以上７％以下のストレッチングを行い、さらにＺｎを主成分とする合金めっきを施すことにより請求項１または２記載のめっき撚り線とした後、樹脂被覆を付与することを特徴とする高耐食性めっき撚り鋼線の製造方法。
【０００８】
【発明の実施の形態】
まず、鋼組成の限定理由について説明する。成分は全て質量％である。
Ｃは、強化に有効な元素であり高強度の鋼線を得るためにはＣ量を０．７％以上とすることが必要であるが、高すぎると初析セメンタイトが析出しやすいため、延性が低下し、かつ伸線性が劣化するのでその上限は１．３％とする。
【０００９】
Ｓｉは、鋼の脱酸のために必要な元素であり、その含有量があまりに少ないと脱酸効果が不十分になるので０．１％以上添加する。また、Ｓｉは熱処理後に形成されるパーライト中のフェライト相に固溶しパテンティング後の強度を上げるが、反面、熱処理性を阻害するので２．０％以下とする。
Ｍｎは、鋼の焼き入れ性を確保するために０．１％以上のＭｎを添加する。しかし、多量のＭｎの添加は、パテンティングの際の変態時間を長くしすぎるので２．０％以下とする。
【００１０】
Ｃｒは、鋼の強度を高める効果を有するので、その効果の発揮される０．０５％以上添加するが、上限は鋼線の延性を引き起こすことのない１．５％以下とする。
Ｎｉは、鋼の強度を上げる効果がある。Ｎｉを添加する場合にはその添加効果のある０．０５％以上添加する。しかし、多量の添加は延性を低下するので１．５％以下とする。
【００１１】
Ｖは、鋼の強度を上げる効果がある。Ｖを添加する場合にはその添加効果のある０．００５％以上添加する。しかし、多量の添加は延性を低下するので上限を１．０％とする。
Ｎｂは、鋼の強度を上げる効果がある。Ｎｂを添加する場合には、その添加効果のある０．００５％以上添加する。しかし、多量の添加は延性を低下するので上限を１．０％とする。
【００１２】
Ｃｕは、耐食性、腐食疲労特性を向上するために添加する。Ｃｕを添加する場合には、その添加効果のある０．０５％添加する。しかし、多量に添加をすると熱間圧延の際に脆化しやすくなるので上限を１．５％とする。
Ａｌは、オーステナイト化したときのγ粒径を微細にパテンティング後の絞りを向上する。Ａｌを添加する場合はその効果が発揮される０．００１％以上添加する。しかし、多量の添加は介在物の量を増加するため上限を０．１％とする。
【００１３】
Ｂもオーステナイト化した際のγ粒径を細粒化する効果がある。この効果により絞りなどの延性を向上する。このため、Ｂを添加する場合にはその効果のある、０．０００５％以上添加する。しかし、０．１％を越えて添加すると熱処理によって変態させる際の変態時間が長くなり過ぎるため上限を０．１％とする。
なお、Ｐ，Ｓについては、従来の極細鋼線と同様に延性を確保するためＳの含有量を０．０２％以下とし、ＰもＳと同様に線材の延性を害するのでその含有量を０．０２％以下とするのが望ましい。
【００１４】
Ｚｎ−１０％Ａｌなどの合金めっきはＺｎと比較して耐食性に優れている。しかし、鋼線にＺｎ−１０％Ａｌ合金などを施して伸線加工した場合には、伸線加工により付着量が相対的に低下する。また、伸線後に合金めっき等を行えば、付着量を保つことができるが、軟質のめっき層を持つ鋼線を撚り合わせるため、撚り線加工後のストランドのリラクゼーション特性が低下する。そこで、本発明者らは２浴法めっきに着目して、始めにＺｎめっきを行い、伸線加工して撚り合わせ、ストレッチングを行い、その後、Ｚｎを主成分とするめっきを行う方法を創出した。
【００１５】
最初にＺｎめっきを行うのは、Ｚｎめっきは比較的簡単に行えるためである。ここで、Ｚｎめっきには３％以下のＡｌ，Ｓｉ，Ｔｉ，Ｍｎ，Ｍｇ，ＲＥＭなどを含むものを用いることができる。次に、伸線加工はＺｎめっきが剥離しない程度に伸線可能な範囲であればどのような加工量でも良い。更に、伸線加工されたワイヤを目的に応じて撚り線加工を行い撚り線とする。この撚り線にストレッチングを行う。ストレッチングを行わずに溶融されたＺｎ合金めっきに撚り線を浸漬すると、撚り線が加熱されリラクゼーション特性が低下する。
【００１６】
このリラクゼーション特性の劣化を抑えるため、ひずみ時効硬化を利用する。このため予めストレッチングを行う。ストレッチングが１％未満ではひずみ時効硬化が小さく、７％を越えてストレッチングを行っても降伏強度の上昇量が飽和するので７％以下とする。その後に行われるＺｎ合金めっきは、４５０℃以上の温度と一般的な時効温度（ブルーイング温度）より高い温度であるが、めっき処理に要する時間が１０秒以下と短い時間で行えるので強度の低下が大きくならないように調整する。
【００１７】
また、伸線加工前にＺｎめっきを施しているため、撚り合わせた後、特に前処理を必要とせずに合金めっきを施すことが可能となる。この結果、得られるめっき撚り線は図１のようにめっき鋼線がより合わさった部分がＺｎ主体のめっきとなり、その外周がＺｎ合金めっきとなる。また、Ｚｎ合金めっきとしては、Ａｌを０．１〜２０％含む亜鉛合金を始めとして特願平１１−３０２６８５号公報に開示されているようなＡｌ以外にさらに耐食性を上げるためＭｇ，Ｓｉ，Ｓｎ，ＲＥＭの１種類以上が添加しても良い。
【００１８】
本発明はストレッチングとブルーイングを組み合わせたが、めっき浴中でのヒートストレッチングを行っても同様の効果が得られる。
また、合金めっきしたＰＣストランドにヒートストレッチングを施した後に、樹脂被覆を行うことでより耐食性をさらに向上できる。樹脂被覆はポリエチレン、エポキシ、ポリウレタン、ポリプロピレン、有機塗料、無機塗料のいずれでも良く、必要とされる環境によって使い分ける必要がある。
【００１９】
【実施例】
以下に実施例に基づいて本発明の効果を記す。表１に試作に用いた供試鋼の化学成分を示す。供試鋼Ａ−１からＡ−４はいずれも本発明法の鋼の化学成分である。
本発明法１〜４は、Ａ−１〜Ａ−４の鋼を連続鋳造で鋳造した後、熱間圧延でビレットとした。このビレットを再加熱後、線材圧延のより直径１１mmの線材とし、直接溶融塩に浸漬してパテンティング処理行った。この線材を酸洗した後、薄く溶融亜鉛めっき処理を施した。その後、１１mmから４．２mmまでの伸線加工を行った。この後、より線加工を行い、直径１２．７mmの７本撚りのＰＣ鋼撚り線とした。さらに、２〜６％のストレッチングを行った後、Ｚｎ−１０％ＡｌのＺｎ合金浴を用いて合金めっき処理を行った。
【００２０】
比較法１は、Ａ−１の鋼を連続鋳造で鋳造した後、熱間圧延でビレットとした。このビレットを再加熱後、線材圧延のより直径１１mmの線材とし、直接溶融塩に浸漬してパテンティング処理を行った。この線材を酸洗した後、１１mmから４．２mmまでの伸線加工を行った。この後、二浴法によるＺｎ−１０％Ａｌ合金めっきを施した。この後、ホットストレッチングを行った。
【００２１】
比較法２は、Ａ−１の鋼を連続鋳造で鋳造した後、熱間圧延でビレットとした。このビレットを再加熱後、線材圧延のより直径１１mmの線材とし、直接溶融塩に浸漬してパテンティング処理を行った。この線材を酸洗した後、伸線加工を行い７mmの径とし、その後二浴法によるＺｎ−１０％Ａｌ合金めっきを施した。その後、７mmから４．２mmまでの伸線加工を行った。この後、ホットストレッチングを行った。
【００２２】
これらの撚り線を用いて、めっき付着量、塩水噴霧５００hr後の腐食減量、リラクゼーション値の測定を行った。この際、ＪＩＳ Ｇ ３５３６に従ってリラクゼーション特性を調査し、ＪＩＳ Ｚ ２３７１に従って５００時間の塩水噴霧試験を行い腐食減量を調査した。
本発明法はめっきの付着量が多く取れるため耐食性が優れ、リラクゼーション特性も優れる結果となっている。一方、比較法１は付着量は多いもののリラクゼーション特性が低下している。比較法２は本発明法と比較するとリラクゼーション特性もおとり、めっきの付着量も少ない結果となっている。
【００２３】
【表１】
【表２】
【発明の効果】
本発明を用いることで、高耐食性と優れたリラクゼーション特性を有するめっき撚り線を得ることができる。
【図面の簡単な説明】
【図１】本発明による一実施例のめっきより線の断面図（２本撚り）。
【図２】本発明による一実施例のめっきより線の断面図（７本撚り）。[0001]
BACKGROUND OF THE INVENTION
In the present invention, hot-rolled wire rods are processed into a finer wire diameter by wire drawing, and are manufactured by twisting a plurality of these, hot-dip galvanized wire, rope, ACSR wire, PC steel stranded wire It relates to stranded steel wires.
[0002]
[Prior art]
PC steel wire is usually manufactured by a method in which a piano wire specified in JIS G3502 is subjected to patenting and then drawn, followed by hot stretching in a temperature range of 300 to 400 ° C.
Since PC steel wire is an environment in which the concrete used is PC, the corrosion resistance of the PC steel wire has been hardly raised. However, in recent years, river sand and mountain sand, which are aggregates of concrete, have been lacking, and sea sand has been used instead. Therefore, the case where corrosion resistance is also required for PC steel wires is increasing. In addition, the number of cases where the PC stranded wire itself is used as an external cable instead of in concrete is expected to improve the corrosion resistance.
[0003]
For this reason, JP-A-59-179755 discloses corrosion of PC steel wires in a salt environment by controlling the steel composition, specifically by adding Cu, Ni, W and reducing the Si content. It is described that suppresses. However, keeping the Si content low is contrary to increasing the strength of the PC steel wire and lowering the relaxation value.
[0004]
On the other hand, coating such as plating on PC steel wire has not been performed so much. This is because when hot-dip Zn plating is performed, the steel wire temperature rises to about 450 ° C., and the relaxation value increases. In addition, the method of drawing after hot-dip Zn plating (so-called after-draw) is preferable in terms of strength characteristics, but since the Zn-Fe alloy layer of hot-dip Zn-plated steel wire is brittle, cracks occur in the plated layer during drawing. Further, since the drawn Zn layer is relatively thinned by the drawing process, it is necessary to carry out thick plating before drawing in order to have sufficient corrosion resistance. However, when the plating thickness is increased, there is a problem that the wire drawing process becomes extremely difficult.
[0005]
On the other hand, in order to improve the corrosion resistance of steel wires, various Zn—Al alloy platings have been developed in place of conventional Zn plating. For example, JP-B 55-26702 discloses Zn-Al, JP-B 54-33223 discloses Zn-Al-Mg, JP-A 57-500475 discloses Zn-Al-Misch metal, JP Japanese Laid-Open Patent Publication No. 56-112252 discloses Zn—Al—Na and the like. Since these are plated by a method in which a steel wire is immersed in an alloy plating bath in a molten state (about 450 ° C.) as in the conventional hot dip Zn plating method, the same problems as the hot dip Zn plating described above exist. . The electrogalvanizing method is not carried out because it is expensive and there is a risk of delayed destruction due to hydrogen intrusion.
[0006]
[Problems to be solved by the invention]
As described above, it has been impossible to produce a highly corrosion-resistant plated stranded steel wire excellent in corrosion resistance by conventional techniques. An object of the present invention is to solve the above-mentioned problems of the conventional method, and to provide a plated stranded steel wire having higher strength and higher corrosion resistance than before and a method for manufacturing the same.
[0007]
[Means for Solving the Problems]
The present invention has been made to solve the above-described problems, and the gist thereof is as follows.
(1) It is a stranded wire made of steel wire, and the portion of the surface of the stranded wire that faces each of the strands is Zn plating, other than the portion that is located on the outside of the strand A high corrosion resistance plated stranded steel wire, characterized in that an alloy plating containing Zn as a main component is applied to the surface .
(2) A stranded wire made of steel wire, in which a core wire or a stranded wire serving as a core exists in the center of the stranded wire, and the core wire or the twist serving as the core out of the surface of the strand existing outside The portion facing the wire is Zn plating, and the surface of the surface other than the portion facing the wire is coated with alloy plating mainly composed of Zn on the surface, and is highly corrosion resistant. Stranded steel wire.
(3) The high corrosion resistance plated stranded steel wire according to claim 1 or 2, wherein the alloy plating containing Zn as a main component is a Zn alloy containing 0.1 to 20% of Al.
(4) The highly corrosion-resistant plating according to any one of claims 1 to 3, wherein any one or more of organic coating, inorganic coating, and organic coating is applied to the outside of the alloy plating layer containing Zn as a main component. Stranded steel wire.
(5) The steel wire is mass%,
C: 0.4 to 1.3%
Si: 0.1 to 2.0%,
Mn: 0.1 to 2.0%,
A high corrosion resistance plated stranded steel wire according to claim 1 or 2, characterized in that a steel wire containing bismuth is used.
(6) The said steel wire is the mass%, and also Cr: 0.05-1.5%, Ni: 0.05-1.5%, V: 0.005-1.0%, Nb: 0 One or more of 0.005 to 1.0% and Mo: 0.005 to 1.0% are added. The high corrosion resistance plated stranded steel wire according to claim 5.
(7) The high corrosion resistance plated stranded steel wire according to claim 5 or 6, wherein the steel wire is added by mass% and Cu: 0.05 to 1.5% is further added.
(8) The steel wire according to any one of claims 5 to 7, wherein the steel wire is added by weight%, and further Al: 0.001 to 0.1% and B: 0.0005 to 0.1% are added. High corrosion resistance plated stranded steel wire according to any of the above items.
(9) The steel wire according to any one of claims 5 to 8, wherein the steel wire is further added by weight%, and P: 0.02% or less and S: 0.02% or less. High corrosion resistance plated stranded steel wire.
(10) A method for producing a highly corrosion-resistant plated stranded steel wire according to any one of claims 5 to 9, wherein the Zn-plated wire having the steel composition according to any one of claims 5 to 9 is used. By wire-drawing to make a wire with a thinner diameter, combining several of them and twisting them together, stretching 1% or more and 7% or less, and further applying alloy plating mainly composed of Zn A method of producing a highly corrosion-resistant plated stranded steel wire, characterized in that the stranded wire according to claim 1 or 2 is used.
(11) A method for producing a highly corrosion-resistant plated stranded steel wire according to any one of claims 5 to 9, wherein the Zn-plated wire having the steel composition according to any one of claims 5 to 9 , Wire drawing to make a wire with a thinner diameter, several of which are combined and twisted, then stretched by 1% or more and 7% or less, and further subjected to alloy plating mainly composed of Zn Item 3. A method for producing a highly corrosion-resistant plated stranded steel wire, which is provided with a resin coating after the plated stranded wire according to item 1 or 2.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
First, the reason for limiting the steel composition will be described. All components are in weight percent.
C is an element effective for strengthening, and in order to obtain a high-strength steel wire, the C content needs to be 0.7% or more, but if it is too high, proeutectoid cementite is likely to be precipitated. And the drawability deteriorates, so the upper limit is made 1.3%.
[0009]
Si is an element necessary for deoxidation of steel, and if its content is too small, the deoxidation effect becomes insufficient, so 0.1% or more is added. Si is dissolved in the ferrite phase in the pearlite formed after the heat treatment to increase the strength after patenting.
Mn is added in an amount of 0.1% or more in order to ensure the hardenability of the steel. However, the addition of a large amount of Mn makes the transformation time during patenting too long, so it is made 2.0% or less.
[0010]
Since Cr has the effect of increasing the strength of the steel, it is added at 0.05% or more where the effect is exhibited, but the upper limit is 1.5% or less which does not cause the ductility of the steel wire.
Ni has the effect of increasing the strength of the steel. In the case of adding Ni, 0.05% or more having the effect of addition is added. However, a large amount of addition lowers the ductility, so it is made 1.5% or less.
[0011]
V has the effect of increasing the strength of the steel. When V is added, 0.005% or more which has the effect of adding V is added. However, the addition of a large amount lowers the ductility, so the upper limit is made 1.0%.
Nb has the effect of increasing the strength of the steel. When Nb is added, 0.005% or more which has the effect of adding Nb is added. However, the addition of a large amount lowers the ductility, so the upper limit is made 1.0%.
[0012]
Cu is added to improve corrosion resistance and corrosion fatigue characteristics. In the case of adding Cu, 0.05% with an effect of the addition is added. However, if it is added in a large amount, it tends to become brittle during hot rolling, so the upper limit is made 1.5%.
Al improves the aperture after patenting finely the γ grain size when austenitized. When Al is added, 0.001% or more is added so that the effect is exhibited. However, the addition of a large amount increases the amount of inclusions, so the upper limit is made 0.1%.
[0013]
B also has the effect of reducing the γ grain size when austenitized. This effect improves the ductility of the aperture. For this reason, when B is added, 0.0005% or more, which is effective, is added. However, if added over 0.1%, the transformation time for transformation by heat treatment becomes too long, so the upper limit is made 0.1%.
In addition, about P and S, in order to ensure ductility similarly to the conventional ultrafine steel wire, the content of S is set to 0.02% or less, and P also harms the ductility of the wire similarly to S, so the content is 0. 0.02% or less is desirable.
[0014]
Alloy plating such as Zn-10% Al is superior in corrosion resistance compared to Zn. However, when the steel wire is drawn by applying a Zn-10% Al alloy or the like, the amount of adhesion is relatively reduced by the drawing. Moreover, if alloy plating etc. are performed after wire drawing, the amount of adhesion can be maintained, but since the steel wire with a soft plating layer is twisted together, the relaxation characteristics of the strand after stranded wire processing are reduced. Therefore, the inventors focused on two-bath plating and created a method of first performing Zn plating, wire drawing, twisting, stretching, and then performing plating mainly composed of Zn. did.
[0015]
The reason why Zn plating is performed first is that Zn plating can be performed relatively easily. Here, as the Zn plating, one containing 3% or less of Al, Si, Ti, Mn, Mg, REM and the like can be used. Next, the wire drawing may be performed in any amount as long as the wire can be drawn to such an extent that the Zn plating does not peel off. Further, the drawn wire is subjected to stranded wire processing according to the purpose to obtain a stranded wire. Stretching is performed on this stranded wire. When a stranded wire is immersed in the molten Zn alloy plating without stretching, the stranded wire is heated and the relaxation characteristics are lowered.
[0016]
In order to suppress the deterioration of the relaxation properties, strain age hardening is used. For this reason, stretching is performed in advance. If the stretching is less than 1%, the strain age hardening is small, and even if stretching exceeds 7%, the increase in yield strength is saturated. The subsequent Zn alloy plating is at a temperature of 450 ° C. or higher and a temperature higher than a general aging temperature (bluing temperature), but the time required for the plating process can be as short as 10 seconds or less, resulting in a decrease in strength. Adjust so that does not increase.
[0017]
Further, since the Zn plating is performed before the wire drawing process, the alloy plating can be performed without any special pretreatment after twisting. As a result, as for the obtained plated stranded wire, as shown in FIG. 1, the portion where the plated steel wires are more combined becomes the Zn-based plating, and the outer periphery thereof becomes the Zn alloy plating. Further, as Zn alloy plating, in addition to Al as disclosed in Japanese Patent Application No. 11-302585 including a zinc alloy containing 0.1 to 20% of Al, Mg, Si, Sn are used to further increase corrosion resistance. , One or more types of REM may be added.
[0018]
Although the present invention combines stretching and bluing, the same effect can be obtained even if heat stretching is performed in a plating bath.
Moreover, after heat-stretching the alloy-plated PC strand, the corrosion resistance can be further improved by performing resin coating. The resin coating may be any of polyethylene, epoxy, polyurethane, polypropylene, organic paint, and inorganic paint, and it is necessary to use properly depending on the required environment.
[0019]
【Example】
The effects of the present invention will be described below based on examples. Table 1 shows the chemical composition of the test steel used in the trial production. Test steels A-1 to A-4 are all chemical components of the steel of the present invention.
In the inventive methods 1 to 4, steels of A-1 to A-4 were cast by continuous casting, and then billeted by hot rolling. The billet was reheated, and the wire was rolled into a wire having a diameter of 11 mm and directly immersed in molten salt for patenting. The wire was pickled and then thinly galvanized. Thereafter, wire drawing from 11 mm to 4.2 mm was performed. After that, twisting was performed to obtain a 7-strand PC steel stranded wire having a diameter of 12.7 mm. Further, after stretching 2 to 6%, alloy plating treatment was performed using a Zn-10% Al Zn alloy bath.
[0020]
In Comparative Method 1, A-1 steel was cast by continuous casting, and then billeted by hot rolling. The billet was reheated, and then a wire rod having a diameter of 11 mm was formed by wire rolling, and was directly immersed in molten salt for patenting. After this wire was pickled, wire drawing from 11 mm to 4.2 mm was performed. Thereafter, Zn-10% Al alloy plating was performed by a two-bath method. Thereafter, hot stretching was performed.
[0021]
In Comparative Method 2, the steel of A-1 was cast by continuous casting, and then billeted by hot rolling. The billet was reheated, and then a wire rod having a diameter of 11 mm was formed by wire rolling, and was directly immersed in molten salt for patenting. After this wire was pickled, it was drawn to a diameter of 7 mm and then plated with Zn-10% Al alloy by a two-bath method. Thereafter, wire drawing from 7 mm to 4.2 mm was performed. Thereafter, hot stretching was performed.
[0022]
Using these stranded wires, the amount of plating adhered, the corrosion weight loss after 500 hours of salt spray, and the relaxation value were measured. At this time, relaxation characteristics were investigated according to JIS G 3536, and a salt spray test for 500 hours was conducted according to JIS Z 2371 to investigate corrosion weight loss.
The method of the present invention is excellent in corrosion resistance because of the large amount of adhesion of plating, resulting in excellent relaxation characteristics. On the other hand, although the comparative method 1 has a large adhesion amount, the relaxation property is lowered. Compared with the method of the present invention, Comparative Method 2 has a relaxation property and results in a smaller amount of plating.
[0023]
[Table 1]
[Table 2]
【The invention's effect】
By using the present invention, a plated stranded wire having high corrosion resistance and excellent relaxation characteristics can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a stranded wire of one embodiment according to the present invention (twist twist).
FIG. 2 is a cross-sectional view of a stranded wire of one embodiment according to the present invention (7 strands).
Claims (11)
Ｃ：０．４〜１．３％、
Ｓｉ：０．１〜２．０％、
Ｍｎ：０．１〜２．０％、
を含有する鋼線を用いることを特徴とする請求項１または２記載の高耐食性めっき撚り鋼線。The steel wire is mass%,
C: 0.4 to 1.3%
Si: 0.1 to 2.0%,
Mn: 0.1 to 2.0%,
A high corrosion resistance plated stranded steel wire according to claim 1 or 2, characterized in that a steel wire containing bismuth is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001111879A JP4527898B2 (en) | 2000-04-10 | 2001-04-10 | High corrosion resistance plated stranded steel wire and method for producing the same |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000108585 | 2000-04-10 | ||
| JP2000-108585 | 2000-04-10 | ||
| JP2001111879A JP4527898B2 (en) | 2000-04-10 | 2001-04-10 | High corrosion resistance plated stranded steel wire and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001355056A JP2001355056A (en) | 2001-12-25 |
| JP4527898B2 true JP4527898B2 (en) | 2010-08-18 |
Family
ID=26589811
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001111879A Expired - Fee Related JP4527898B2 (en) | 2000-04-10 | 2001-04-10 | High corrosion resistance plated stranded steel wire and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4527898B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59193892U (en) * | 1983-06-06 | 1984-12-22 | 西矢製鋼株式会社 | wire rope |
| JPH05230782A (en) * | 1991-12-27 | 1993-09-07 | Nippon Cable Syst Inc | Rope for operation |
| JPH06293979A (en) * | 1993-04-08 | 1994-10-21 | Kawatetsu Techno Wire Kk | High fatigue strength and low relaxation galvanized pc steel-stranded wire and its production |
| JPH0853737A (en) * | 1994-08-11 | 1996-02-27 | Kobe Steel Ltd | High strength and high toughness hot-dip plated steel wire and its production |
| JP2000080442A (en) * | 1998-07-06 | 2000-03-21 | Sumitomo Metal Ind Ltd | Steel wire rod, extra fine steel wire and stranded steel wire |
-
2001
- 2001-04-10 JP JP2001111879A patent/JP4527898B2/en not_active Expired - Fee Related
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59193892U (en) * | 1983-06-06 | 1984-12-22 | 西矢製鋼株式会社 | wire rope |
| JPH05230782A (en) * | 1991-12-27 | 1993-09-07 | Nippon Cable Syst Inc | Rope for operation |
| JPH06293979A (en) * | 1993-04-08 | 1994-10-21 | Kawatetsu Techno Wire Kk | High fatigue strength and low relaxation galvanized pc steel-stranded wire and its production |
| JPH0853737A (en) * | 1994-08-11 | 1996-02-27 | Kobe Steel Ltd | High strength and high toughness hot-dip plated steel wire and its production |
| JP2000080442A (en) * | 1998-07-06 | 2000-03-21 | Sumitomo Metal Ind Ltd | Steel wire rod, extra fine steel wire and stranded steel wire |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001355056A (en) | 2001-12-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4842408B2 (en) | Wire, steel wire, and method for manufacturing wire | |
| JP4782246B2 (en) | High-strength Zn-Al plated steel wire for bridges with excellent corrosion resistance and fatigue characteristics and method for producing the same | |
| JP5169839B2 (en) | PWS plated steel wire with excellent twisting characteristics and manufacturing method thereof | |
| CN108239735A (en) | High tough, permanent seal cooling bridge cable 1960MPa grades of Zn-Al Alloy Coated Steel Wires of major diameter | |
| JP2921978B2 (en) | Manufacturing method of high strength and high ductility ultrafine steel wire | |
| EP1069199B1 (en) | High-fatigue-strength steel wire and production method therefor | |
| JP4331915B2 (en) | High strength and high ductility hot dip galvanized steel sheet excellent in fatigue durability and corrosion resistance and method for producing the same | |
| JP2000309824A (en) | Cold rolled steel sheet, hot dip plated steel sheet and their production | |
| JPH0853737A (en) | High strength and high toughness hot-dip plated steel wire and its production | |
| JP3965010B2 (en) | High-strength direct patenting wire and method for producing the same | |
| JP2002317388A (en) | Plated strand steel wire having high corrosion resistance and method for producing the same | |
| JP3725576B2 (en) | Manufacturing method of high strength galvanized steel wire | |
| JP4527898B2 (en) | High corrosion resistance plated stranded steel wire and method for producing the same | |
| JP3176226B2 (en) | Manufacturing method of high strength and high toughness hot-dip coated steel wire | |
| JP3984393B2 (en) | High-strength steel wire without delamination and method for producing the same | |
| JP3057372B2 (en) | Method for producing Zn-Al alloy-plated steel wire excellent in corrosion resistance and fatigue resistance | |
| JP2000309847A (en) | Hot rolled steel sheet, hot-dip metal coated hot rolled steel sheet, and their manufacture | |
| JP2002146475A (en) | Galvannealed steel sheet | |
| JP2500947B2 (en) | Manufacturing method of high strength steel wire for suspension structure | |
| JP3370368B2 (en) | Manufacturing method of high strength steel wire for suspended structure | |
| JP3330233B2 (en) | Manufacturing method of hot-dip Zn-Al plated steel wire | |
| JP2769843B2 (en) | Manufacturing method of alloy plated steel wire | |
| JP2003328077A (en) | High-strength rolled and plated pc steel bar, and manufacturing method therefor | |
| JP2502022B2 (en) | Plated steel wire with excellent corrosion resistance and method for producing the same | |
| JP3298686B2 (en) | Method for producing high-strength galvanized steel wire for ACSR with excellent corrosion resistance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20070903 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100224 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100302 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20100506 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100525 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100604 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130611 Year of fee payment: 3 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 4527898 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130611 Year of fee payment: 3 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130611 Year of fee payment: 3 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |