JP2000119805A - Steel wire rod excellent in wire drawability - Google Patents

Steel wire rod excellent in wire drawability

Info

Publication number
JP2000119805A
JP2000119805A JP26982298A JP26982298A JP2000119805A JP 2000119805 A JP2000119805 A JP 2000119805A JP 26982298 A JP26982298 A JP 26982298A JP 26982298 A JP26982298 A JP 26982298A JP 2000119805 A JP2000119805 A JP 2000119805A
Authority
JP
Japan
Prior art keywords
wire
less
content
steel
steel wire
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.)
Granted
Application number
JP26982298A
Other languages
Japanese (ja)
Other versions
JP3536684B2 (en
Inventor
Yoshihiro Ofuji
善弘 大藤
Takanari Hamada
貴成 浜田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sumitomo Metal Industries Ltd filed Critical Sumitomo Metal Industries Ltd
Priority to JP26982298A priority Critical patent/JP3536684B2/en
Publication of JP2000119805A publication Critical patent/JP2000119805A/en
Application granted granted Critical
Publication of JP3536684B2 publication Critical patent/JP3536684B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a high carbon steel wire rod excellent in wire drawability and causing no breaking of wire even in the case of wire drawing to >2.60 amount of true strain and suitably used for wire rope, PC steel bar, bead wire, steel cord, or the like. SOLUTION: In the cross section of a steel wire rod having a composition consisting of, by weight, 0.7-1.1% C, 0.1-1.5% Si, 0.2-1.0% Mn, <=1.0% Cr, <=0.05% Al, <=0.006% N, <=1.0% Cu, <=2.0% Ni, <=0.5% Mo, <=0.5% W, <=4.0% Co, <=0.4% V, <=0.1% Nb, <=0.1% Ti, <=0.1% Zr, <=0.005% B, <=0.05% P, <=0.05% S, <=0.10% rare earth elements, <=0.01% Ca, <=0.01% Mg, and the balance Fe with impurities, the average value of C content in the region from the outside periphery to the position at a depth one-fiftieth the radius of the above steel wire rod is regulated to (0.6 to 0.9)×C% (where C means C content in the wire rod).

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、伸線加工性に優れ
た鋼線材に関する。より詳しくは、例えば、ワイヤロー
プ、PC鋼線、ビードワイヤー、スチールコードなどの
用途に好適な伸線加工性に優れた鋼線材に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel wire rod excellent in wire drawability. More specifically, for example, the present invention relates to a steel wire rod excellent in drawability suitable for applications such as wire rope, PC steel wire, bead wire, and steel cord.

【0002】[0002]

【従来の技術】ワイヤロープ、PC鋼線は、一般に、熱
間圧延して得た鋼線材(以下、「鋼線材」を単に「線
材」という)に伸線加工を施し、更に、焼入れ焼戻しの
調質処理、あるいはブルーイング処理を施して製造され
る。又、自動車のラジアルタイアの補強材として用いら
れるスチールコード用極細鋼線は、以下に示すような工
程で製造されている。すなわち、熱間圧延後調整冷却し
た線径が約5.5mmの線材を、1次伸線加工して直径
を3mm前後にし、次いで、パテンティング処理を行
い、更に2次伸線加工して1.5mm前後の直径にす
る。この後、最終パテンティング処理を行い、次いで、
ブラスメッキを施し、更に最終湿式伸線加工を施して直
径0.2〜0.4mmにする。このようにして得られた
極細鋼線を、更に撚り加工で複数本撚り合わせて撚鋼線
とすることでスチールコードが製造される。
2. Description of the Related Art Generally, a wire rope and a PC steel wire are subjected to wire drawing to a steel wire obtained by hot rolling (hereinafter, "steel wire" is simply referred to as "wire") and further subjected to quenching and tempering. It is manufactured by subjecting it to a tempering treatment or a bluing treatment. An ultrafine steel wire for a steel cord used as a reinforcing material for a radial tire of an automobile is manufactured by the following process. That is, a wire rod having a diameter of about 5.5 mm adjusted and cooled after hot rolling is subjected to primary drawing to a diameter of about 3 mm, then subjected to patenting, and further subjected to secondary drawing to obtain 1 mm. The diameter is about 0.5 mm. After this, a final patenting process is performed, and then
Brass plating is performed, and final wet drawing is performed to a diameter of 0.2 to 0.4 mm. A steel cord is manufactured by twisting a plurality of the extra-fine steel wires obtained in this manner by twisting to obtain a twisted steel wire.

【0003】一般に、線材を鋼線に加工する際に断線が
生ずると、生産性と歩留りが大きく低下してしまう。し
たがって、上記技術分野に属する線材は、伸線加工時、
特にスチールコードを製造する場合は強度の冷間加工が
行われる湿式伸線加工時に、断線しないことが強く要求
される。
In general, when a wire is broken into a steel wire, breakage occurs, and productivity and yield are greatly reduced. Therefore, the wire rod belonging to the above technical field, at the time of wire drawing,
Particularly, in the case of manufacturing a steel cord, it is strongly required not to break the wire at the time of wet drawing in which strong cold working is performed.

【0004】更に、スチールコードの製造の場合、熱間
圧延した直径5.5mmの線材を直径が約1.5mmの
鋼線にするのに多くの中間処理工程を要し、製造コスト
の上昇を招いている。したがって、最終製品の性能を低
下させることなく、製造工程を簡略化したいとする産業
界からの要望が大きくなっている。このため、C含有量
が0.7%未満の比較的強度の低い炭素鋼線材などで
は、中間処理を省略して、例えば直径5.5mmから
1.5mmまで直接に伸線する技術が開発されている。
なお、前記伸線における真歪量は2.60である。ここ
で、真歪(ε)は線材の直径(d0 )と伸線後の鋼線の
直径(d)を用いて下記の(i)式で表されるものであ
る。
Further, in the case of manufacturing a steel cord, many intermediate processing steps are required to convert a hot-rolled wire having a diameter of 5.5 mm into a steel wire having a diameter of about 1.5 mm, which increases the manufacturing cost. Inviting. Therefore, there is an increasing demand from the industry to simplify the manufacturing process without deteriorating the performance of the final product. For this reason, in the case of a relatively low-strength carbon steel wire having a C content of less than 0.7%, a technique of directly drawing a wire from 5.5 mm to 1.5 mm in diameter without intermediate treatment has been developed. ing.
Note that the true strain amount in the wire drawing is 2.60. Here, the true strain (ε) is represented by the following equation (i) using the diameter (d 0 ) of the wire and the diameter (d) of the drawn steel wire.

【0005】ε=2loge(d0/d)・・・(i) 一方では、近年、種々の目的からスチールコードなどを
軽量化する動きが高まってきた。このため、前記の各種
製品に対して高強度が要求されるようになり、上記のC
含有量が0.7%未満の炭素鋼線材などでは、所望の高
強度が得られなくなっている。このため、C含有量が高
くて鋼線に高い強度を確保させることができ、しかも前
記の中間処理を省略できるような伸線加工性に優れた線
材に対する要求が極めて大きくなっている。
Ε = 2log e (d 0 / d) (i) On the other hand, in recent years, there has been an increasing movement to reduce the weight of steel cords and the like for various purposes. For this reason, high strength is required for the various products described above, and the above C
With a carbon steel wire having a content of less than 0.7%, a desired high strength cannot be obtained. For this reason, there is an extremely large demand for a wire rod which has a high C content and can secure a high strength to a steel wire, and which has excellent drawability such that the intermediate treatment can be omitted.

【0006】又、ワイヤロープ、PC鋼線など太径の製
品においては、熱間圧延線材を最終製品径にまで伸線加
工する。したがって、伸線加工性を高めて冷間加工度を
大きくできれば、これまでよりも強度の高い製品を得る
ことが可能となるので、軽量化が期待できる。このた
め、太径の製品においても、冷間での伸線加工性に優れ
た線材に対する要求が大きくなっている。
In the case of products having a large diameter such as a wire rope and a PC steel wire, a hot-rolled wire is drawn to a final product diameter. Therefore, if the degree of cold working can be increased by increasing the wire drawing workability, it is possible to obtain a product having higher strength than before, and thus a reduction in weight can be expected. For this reason, even for products having a large diameter, there is an increasing demand for a wire rod having excellent cold-drawability.

【0007】上記した近年の産業界からの要望に対し
て、偏析やミクロ組織を制御して線材の伸線加工性を高
める技術が提案されている。
[0007] In response to the above-mentioned demands from the industry in recent years, there has been proposed a technique for controlling segregation and microstructure to enhance the wire drawing workability of a wire.

【0008】例えば、特公平7−11060号公報に
は、線材のMnの偏析を制御する「伸線加工性のすぐれ
た高強度鋼線材」が開示されている。しかし、この公報
で提案された技術は、線材におけるMnの偏析ピーク幅
を小さくするために、鋳片サイズを大きくとって圧減
比を高める、中心偏析を改善するために鋳造時の溶鋼
過熱度を低めとする、鋳型内電磁撹拌を行う、凝固
末期に鋳片に圧下をかける、鋳片を均熱炉中で加熱し
偏析元素を拡散させる、などの特殊な処理を必要とす
る。このため、線材の製造工程や製造設備が異なる場合
には、必ずしも適用できないものであるし、たとえ適用
できたとしても製造コストが嵩むものであった。更に、
Mnの偏析を制御しても、熱間圧延した線材の絞りの向
上には寄与するが、前記した中間処理としてのパテンテ
ィングを省略するには不十分であった。
For example, Japanese Patent Publication No. 7-11060 discloses a "high-strength steel wire excellent in wire drawing workability" for controlling segregation of Mn in a wire. However, the technology proposed in this publication is to increase the pressure reduction ratio by increasing the slab size in order to reduce the Mn segregation peak width in the wire, and to improve the center segregation in order to improve center segregation. Special treatments such as lowering the temperature, performing electromagnetic stirring in the mold, applying pressure to the slab at the end of solidification, and heating the slab in a soaking furnace to diffuse the segregated elements are required. For this reason, when the manufacturing process or manufacturing equipment of a wire is different, it cannot always be applied, and even if it can be applied, the manufacturing cost increases. Furthermore,
Controlling the segregation of Mn also contributes to the improvement of the drawing of the hot-rolled wire rod, but is insufficient to omit the patenting as the intermediate treatment described above.

【0009】特開平6−73502号公報には、2段変
態により得られた上部ベイナイト組織が面積率で80%
である「伸線加工性に優れた高炭素鋼線材または鋼線」
が開示されている。しかし、2段変態により上部ベイナ
イト組織を得るためには、熱間圧延後に線材を直接溶融
塩に浸漬して冷却することが必要で、この処理のための
特殊な設備を設ける必要があり、設備コストの上昇を招
く。更に、上記のような溶融塩を媒体とした冷却を行う
と、それが線材の表面に付着し、付着した塩を除去する
工程が必要になり、製造コストの一層の上昇をきたす。
Japanese Patent Application Laid-Open No. Hei 6-73502 discloses that the upper bainite structure obtained by the two-stage transformation has an area ratio of 80%.
"High-carbon steel wire or steel wire with excellent wire drawability"
Is disclosed. However, in order to obtain the upper bainite structure by two-stage transformation, it is necessary to immerse the wire directly in molten salt and cool it after hot rolling, and it is necessary to provide special equipment for this treatment. This leads to higher costs. Further, when the above-described cooling is performed using the molten salt as a medium, the molten salt adheres to the surface of the wire, and a step of removing the adhered salt is required, which further increases the production cost.

【0010】特公平7−11060号公報や特開平6−
73502号公報で提案された技術によれば、一応は伸
線加工性に優れた線材を得ることができる。しかし、既
に述べたように、設備コストや製造コストが嵩むという
大きな問題があった。
[0010] Japanese Patent Publication No. Hei 7-11060 and Japanese Unexamined Patent Publication No.
According to the technique proposed in Japanese Patent No. 73502, a wire rod excellent in drawability can be obtained. However, as described above, there is a major problem that equipment costs and manufacturing costs increase.

【0011】[0011]

【発明が解決しようとする課題】本発明は、上記現状に
鑑みなされたもので、その目的は、ワイヤロープ、PC
鋼線、ビードワイヤー、スチールコードなどの用途に好
適な伸線加工性に優れた高炭素鋼線材、なかでも前記し
た真歪量で2.60を超えて伸線加工しても断線を生ず
ることがない高炭素鋼線材を廉価に提供することであ
る。
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object the object of the present invention to provide a wire rope, a PC,
High carbon steel wire with excellent drawability suitable for applications such as steel wire, bead wire, and steel cord. Above all, the wire may break even if it is drawn with a true strain of more than 2.60. The aim is to provide a low-carbon steel wire rod without any cost.

【0012】[0012]

【課題を解決するための手段】本発明の要旨は、下記
(1)及び(2)に示す伸線加工性に優れた線材にあ
る。
SUMMARY OF THE INVENTION The gist of the present invention is a wire excellent in wire drawing work shown in the following (1) and (2).

【0013】(1)重量%で、C:0.7〜1.1%、
Si:0.1〜1.5%、Mn:0.2〜1.0%、C
r:1.0%以下、Al:0.05%以下、N:0.0
06%以下、Cu:1.0%以下、Ni:2.0%以
下、Mo:0.5%以下、Co:4.0%以下、V:
0.4%以下、Nb:0.1%以下、Ti:0.1%以
下、B:0.005%以下、P:0.05%以下、S:
0.05%以下、希土類元素:0.10%以下、Ca:
0.01%以下、Mg:0.01%以下を含有し、残部
はFe及び不可避不純物からなる線材の横断面におい
て、外周から前記線材の半径の1/50の深さの位置ま
での領域におけるC含有量の平均値が0.6〜0.9×
C%(但し、Cは線材のC含有量)であることを特徴と
する伸線加工性に優れた線材。
(1) By weight%, C: 0.7-1.1%,
Si: 0.1 to 1.5%, Mn: 0.2 to 1.0%, C
r: 1.0% or less, Al: 0.05% or less, N: 0.0
06% or less, Cu: 1.0% or less, Ni: 2.0% or less, Mo: 0.5% or less, Co: 4.0% or less, V:
0.4% or less, Nb: 0.1% or less, Ti: 0.1% or less, B: 0.005% or less, P: 0.05% or less, S:
0.05% or less, rare earth element: 0.10% or less, Ca:
0.01% or less, Mg: 0.01% or less, the balance being in a region from the outer periphery to a position at a depth of 1/50 of the radius of the wire in the cross section of the wire made of Fe and unavoidable impurities. The average value of the C content is 0.6 to 0.9 ×
A wire having excellent drawability, characterized by C% (where C is the C content of the wire).

【0014】(2)重量%で、C:0.7〜1.1%、
Si:0.1〜1.5%、Mn:0.2〜1.0%、C
r:1.0%以下、Al:0.05%以下、N:0.0
06%以下、Cu:1.0%以下、Ni:2.0%以
下、Mo:0.5%以下、W:0.5%以下、Co:
4.0%以下、V:0.4%以下、Nb:0.1%以
下、Ti:0.1%以下、Zr:0.1%以下、B:
0.005%以下、P:0.05%以下、S:0.05
%以下、希土類元素:0.10%以下、Ca:0.01
%以下、Mg:0.01%以下を含有し、残部はFe及
び不可避不純物からなる線材の横断面において、外周か
ら前記線材の半径の1/50の深さの位置までの領域に
おけるC含有量の平均値が0.6〜0.9×C%(但
し、Cは線材のC含有量)であることを特徴とする伸線
加工性に優れた線材。
(2) C: 0.7 to 1.1% by weight,
Si: 0.1 to 1.5%, Mn: 0.2 to 1.0%, C
r: 1.0% or less, Al: 0.05% or less, N: 0.0
06% or less, Cu: 1.0% or less, Ni: 2.0% or less, Mo: 0.5% or less, W: 0.5% or less, Co:
4.0% or less, V: 0.4% or less, Nb: 0.1% or less, Ti: 0.1% or less, Zr: 0.1% or less, B:
0.005% or less, P: 0.05% or less, S: 0.05
% Or less, rare earth element: 0.10% or less, Ca: 0.01
%, Mg: 0.01% or less, the balance being the C content in the region from the outer periphery to a position at a depth of 1/50 of the radius of the wire in the cross section of the wire made of Fe and unavoidable impurities. Is an average of 0.6 to 0.9 × C% (where C is the C content of the wire).

【0015】なお、本発明でいう線材の「横断面」と
は、線材の圧延方向に垂直に切断した面をいう。又、
「線材の最外層から前記線材の半径の1/50の深さの
位置までの領域におけるC含有量の平均値」とは、例え
ば波長分散型の電子線マイクロアナライザーを用いて線
材外周部(表層部近傍)のC含有量の線分析を行った場
合の、外周から半径の4/250、3/250、2/2
50及び1/250の深さの位置におけるC含有量の平
均値を指す。
The "cross-section" of the wire in the present invention means a surface cut perpendicular to the rolling direction of the wire. or,
The “average value of the C content in a region from the outermost layer of the wire to a position at a depth of 1/50 of the radius of the wire” means, for example, the outer peripheral portion of the wire (surface layer) using a wavelength-dispersive electron beam microanalyzer. Of the radius from the outer circumference when a line analysis of the C content was performed.
It refers to the average value of the C content at 50 and 1/250 depth positions.

【0016】本発明者らは、熱間圧延した高炭素鋼線材
の組織、なかでも表層部組織が伸線加工性に及ぼす影響
について調査・研究を重ね、その結果、下記の知見を得
た。
The present inventors have repeatedly conducted studies and studies on the structure of a hot-rolled high-carbon steel wire rod, particularly the effect of the surface layer structure on drawability. As a result, the following findings were obtained.

【0017】(a)曲げ加工や鍛造の場合と異なり冷間
での伸線加工は多段、且つ、大きな加工度で行われるた
め、表層部に軟質なフェライト組織が存在すれば却って
加工性が低下し、伸線加工中に断線を生じ易い。つま
り、鋼材の表層部に軟質なフェライト組織を存在させる
ことにより、冷間での曲げ加工性や鍛造性を高めようと
する特開昭56−55520号公報や特開平8−109
437号公報で提案されている技術は、これを伸線加工
に適用しても、伸線加工性を高めることはできない。し
かし、線材の表層部(外周近傍)の硬度を、母材部硬度
(以下、中心部の硬度という)より低くすれば冷間での
伸線加工時の変形抵抗が減少するので、伸線加工性を高
めることができる。
(A) Unlike the case of bending or forging, cold drawing is performed in multiple steps and with a large degree of work, so that if a soft ferrite structure exists in the surface layer, workability is rather deteriorated. However, the wire is easily broken during the wire drawing. That is, JP-A-56-55520 and JP-A-8-109 attempt to enhance cold workability and forgeability by having a soft ferrite structure in the surface layer of a steel material.
The technique proposed in Japanese Patent No. 437 cannot improve the wire drawing workability even if it is applied to wire drawing. However, if the hardness of the surface layer portion (near the outer periphery) of the wire is lower than the hardness of the base material portion (hereinafter referred to as the hardness of the central portion), the deformation resistance during cold wire drawing decreases, so that the wire drawing is performed. Can be enhanced.

【0018】(b)線材の外周近傍の硬度を中心部の硬
度より下げるためには、外周近傍の炭素含有量を低下さ
せれば良い。
(B) In order to lower the hardness near the outer periphery of the wire than the hardness at the center, the carbon content near the outer periphery may be reduced.

【0019】(c)外周近傍の炭素含有量の平均値を
0.6重量%以上にすれば、組織中に初析フェライトが
析出することがないので、冷間伸線時の限界加工度を高
めることができる。
(C) If the average value of the carbon content in the vicinity of the outer periphery is set to 0.6% by weight or more, proeutectoid ferrite does not precipitate in the structure. Can be enhanced.

【0020】(d)上記(a)〜(c)から、外周近傍
の炭素含有量が適正な範囲にあれば、伸線加工性を高め
ることが可能である。そして、これによって冷間伸線に
用いるダイス寿命を向上させることもできる。
(D) From the above (a) to (c), if the carbon content in the vicinity of the outer periphery is within an appropriate range, it is possible to enhance the drawability. Thus, the life of a die used for cold drawing can be improved.

【0021】本発明は、上記の知見に基づいて完成され
たものである。
The present invention has been completed based on the above findings.

【0022】[0022]

【発明の実施の形態】以下、本発明について詳しく説明
する。なお、化学成分の含有量の「%」は「重量%」を
意味する。
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In addition, “%” of the content of the chemical component means “% by weight”.

【0023】(A)線材の化学組成 C:0.7〜1.1% Cは、強度を確保するのに有効な元素である。しかし、
その含有量が0.7%未満の場合にはワイヤロープ、P
C鋼線、ビードワイヤー、スチールコードなどの最終製
品に安定して高い強度を付与させることが困難である。
一方、Cの含有量が多すぎると鋼材が硬質化して冷間加
工性の低下を招く。特に、C含有量が1.1%を超える
と、線材が硬質化するばかりでなく、初析セメンタイト
(つまり、旧オーステナイト粒界に沿うセメンタイト)
の生成防止が困難になって伸線加工性が低下する。この
ため、外周近傍の炭素含有量を後述する範囲に制御して
も、真歪量で2.60を超えるような大きな加工度で伸
線すれば断線が多発する。したがって、Cの含有量を
0.7〜1.1%とした。
(A) Chemical composition of wire rod C: 0.7 to 1.1% C is an element effective for securing strength. But,
If the content is less than 0.7%, wire rope, P
It is difficult to stably impart high strength to final products such as C steel wire, bead wire, and steel cord.
On the other hand, if the content of C is too large, the steel material becomes hard and causes a reduction in cold workability. In particular, when the C content exceeds 1.1%, not only the wire becomes hardened, but also proeutectoid cementite (that is, cementite along the prior austenite grain boundary).
It is difficult to prevent the formation of manganese, and the wire drawing workability is reduced. For this reason, even if the carbon content in the vicinity of the outer periphery is controlled to a range described later, disconnection occurs frequently if the wire is drawn with a large working degree exceeding 2.60 in true strain. Therefore, the content of C is set to 0.7 to 1.1%.

【0024】Si:0.1〜1.5% Siは、強度を高めるのに有効な元素である。更に、脱
酸剤として必要な元素でもある。しかし、その含有量が
0.1%未満では添加効果に乏しく、一方、1.5%を
超えると伸線加工での限界加工度が低下し、真歪量で
2.60を超えるような大きな加工度で伸線すれば断線
が多発する。したがって、Si含有量を0.1〜1.5
%とした。
Si: 0.1-1.5% Si is an effective element for increasing the strength. Further, it is an element necessary as a deoxidizing agent. However, if the content is less than 0.1%, the effect of addition is poor. On the other hand, if the content exceeds 1.5%, the critical workability in wire drawing decreases, and the true strain exceeds 2.60. If the wire is drawn at the degree of processing, disconnection frequently occurs. Therefore, the Si content is set to 0.1 to 1.5.
%.

【0025】Mn:0.2〜1.0% Mnは、強度を高める作用に加えて、鋼中のSをMnS
として固定して熱間脆性を防止する作用を有する。しか
し、その含有量が0.2%未満では前記の効果が得難
い。一方、Mnは偏析しやすい元素であり、1.0%を
超えると特に線材の中心部に偏析し、その偏析部にはマ
ルテンサイトやベイナイトが生成するので、伸線加工性
が低下してしまう。したがって、Mn含有量を0.2〜
1.0%とした。
Mn: 0.2-1.0% In addition to the effect of increasing the strength, Mn can reduce S in steel to MnS
And has the effect of preventing hot brittleness. However, if the content is less than 0.2%, it is difficult to obtain the above effects. On the other hand, Mn is an element that is easily segregated. If it exceeds 1.0%, Mn is segregated particularly at the center of the wire, and martensite and bainite are generated at the segregated portion, so that the wire drawing workability is reduced. . Therefore, the Mn content is 0.2 to
1.0%.

【0026】Cr:1.0%以下 Crは添加しなくても良い。添加すれば、パーライトの
ラメラ間隔を小さくして圧延後及びパテンティング後の
強度を高める作用を有する。又、伸線加工を初めとする
冷間加工時の加工硬化率を高める働きがあるので、Cr
の添加によって比較的低い加工率でも高強度を得ること
ができる。こうした効果を確実に得るには、Crは0.
1%以上の含有量とすることが好ましい。一方、Crを
過剰に添加するとパーライト変態が終了するまでの時間
が長くなり、熱間圧延後の線材の中心部にマルテンサイ
トやベイナイトが生成するため、伸線加工中の断線頻度
が増加する。特に、Cr含有量が1.0%を超えると、
真歪量で2.60を超えるような大きな加工度で伸線す
れば断線が多発する。したがって、Crの含有量を1.
0%以下とした。
Cr: 1.0% or less Cr need not be added. If added, it has the effect of reducing the lamella spacing of pearlite and increasing the strength after rolling and after patenting. In addition, since it has the function of increasing the work hardening rate during cold working such as wire drawing,
High strength can be obtained even at a relatively low processing rate by adding. To ensure such an effect, Cr should be contained in an amount of 0.
The content is preferably 1% or more. On the other hand, if Cr is added excessively, the time until the pearlite transformation ends is increased, and martensite and bainite are generated at the center of the wire after hot rolling, so that the frequency of breakage during wire drawing increases. In particular, when the Cr content exceeds 1.0%,
If the wire is drawn with a large working degree such that the true strain exceeds 2.60, disconnection frequently occurs. Therefore, if the content of Cr is 1.
0% or less.

【0027】Al:0.05%以下 Alは、脱酸材として有効な元素である。しかし、Al
の含有量が0.05%を超えると、Al23を主成分と
する酸化物系介在物が粗大になり、伸線加工中に断線が
多発する。したがって、Alの含有量は0.050%以
下とする必要がある。なお、最終製品の線径が直径で
0.5mm以下の場合は、Al23を主成分とする酸化
物系介在物が微細であっても、最終伸線時に断線する原
因となる。このため、上記サイズの最終製品の素材とし
て用いる場合には、線材のAl含有量を0.003%以
下にすることが好ましい。
Al: 0.05% or less Al is an element effective as a deoxidizing material. However, Al
When the content exceeds 0.05%, oxide inclusions mainly composed of Al 2 O 3 become coarse, and wire breakage frequently occurs during wire drawing. Therefore, the content of Al needs to be 0.050% or less. If the wire diameter of the final product is 0.5 mm or less in diameter, even if the oxide-based inclusions mainly composed of Al 2 O 3 are fine, they may cause breakage during the final drawing. Therefore, when used as a material for a final product of the above size, the Al content of the wire is preferably set to 0.003% or less.

【0028】N:0.006%以下 Nは、冷間での伸線加工中に転位に固着し、鋼線の強度
を上昇させる一方、伸線加工性を低下させてしまう。し
かし、このNの悪影響はその含有量を0.006%以下
にすることで防止できる。したがって、N含有量を0.
006%以下とした。
N: 0.006% or less N adheres to dislocations during cold drawing, and increases the strength of the steel wire, but decreases the drawability. However, this adverse effect of N can be prevented by setting the content to 0.006% or less. Therefore, the N content is set to 0.1.
006% or less.

【0029】Cu:1.0%以下 Cuは添加しなくてもよい。添加すれば耐食性を高める
作用がある。この効果を確実に得るには、Cuは0.0
5%以上の含有量とすることが好ましい。しかし、その
含有量が1.0%を超えると結晶粒界に偏析して鋼塊の
分塊圧延や線材の熱間圧延など熱間加工時における割れ
や疵の発生が顕著になる。したがって、Cuの含有量を
1.0%以下とした。
Cu: 1.0% or less Cu need not be added. If added, it has the effect of increasing corrosion resistance. To ensure this effect, Cu must be 0.0
Preferably, the content is 5% or more. However, if the content exceeds 1.0%, segregation occurs at the crystal grain boundaries, and cracks and flaws become noticeable during hot working such as bulk rolling of steel ingots and hot rolling of wire rods. Therefore, the content of Cu is set to 1.0% or less.

【0030】Ni:2.0%以下 Niは添加しなくてもよい。添加すれば、フェライト中
に固溶してフェライトの靭性を向上させる効果を発揮す
る。この効果を確実に得るには、Niは0.2%以上の
含有量とすることが好ましい。しかし、その含有量が
2.0%を超えると、焼入れ性が高くなり過ぎてマルテ
ンサイトが生成し易くなり伸線加工性が劣化する。した
がって、Niの含有量を2.0%以下とした。
Ni: 2.0% or less Ni may not be added. If added, it has the effect of forming a solid solution in the ferrite and improving the toughness of the ferrite. In order to ensure this effect, it is preferable that the content of Ni be 0.2% or more. However, when the content exceeds 2.0%, the hardenability becomes too high, so that martensite is easily generated and the wire drawing workability deteriorates. Therefore, the content of Ni is set to 2.0% or less.

【0031】Mo:0.5%以下 Moは添加しなくてもよい。添加すれば、熱処理で微細
な炭化物として析出し強度と疲労特性を高める作用があ
る。この効果を確実に得るには、Moは0.05%以上
の含有量とすることが好ましい。一方、0.5%を超え
て含有させても前記の効果は飽和し、コストが嵩むばか
りである。したがって、Moの含有量を0.5%以下と
した。
Mo: 0.5% or less Mo may not be added. If added, it precipitates as fine carbides by heat treatment and has the effect of increasing strength and fatigue properties. To ensure this effect, it is preferable that the content of Mo be 0.05% or more. On the other hand, if the content exceeds 0.5%, the above effect is saturated and the cost is increased. Therefore, the content of Mo is set to 0.5% or less.

【0032】W:0.5%以下 Wは添加しなくてもよい。添加すれば、熱処理で微細な
炭化物として析出し強度を高める効果がある。又、Wは
耐食性の向上にも有効に作用する。これらの効果を確実
に得るには、Wは0.05%以上の含有量とすることが
好ましい。一方、0.5%を超えて含有させても前記の
効果は飽和し、コストが嵩むばかりである。したがっ
て、Wの含有量を0.5%以下とした。
W: 0.5% or less W may not be added. If added, it has the effect of increasing the strength by precipitation as fine carbides by heat treatment. W also effectively acts to improve corrosion resistance. In order to surely obtain these effects, the content of W is preferably set to 0.05% or more. On the other hand, if the content exceeds 0.5%, the above effect is saturated and the cost is increased. Therefore, the content of W is set to 0.5% or less.

【0033】Co:4.0%以下 Coは添加しなくても良い。添加すれば、初析セメンタ
イトの析出を防止し、更にパーライトを微細化して強度
を高める作用を有する。この効果を確実に得るには、C
oは0.2%以上の含有量とすることが好ましい。しか
し、4.0%を超えて含有させても前記の効果は飽和
し、コストが嵩むばかりである。したがって、Coの含
有量を4.0%以下とした。
Co: 4.0% or less Co may not be added. When added, it has the effect of preventing precipitation of proeutectoid cementite and further increasing the strength by refining pearlite. To ensure this effect, C
It is preferable that the content of o is 0.2% or more. However, even if the content exceeds 4.0%, the above effect is saturated and the cost is increased. Therefore, the content of Co is set to 4.0% or less.

【0034】V:0.4%以下 Vは添加しなくてもよい。添加すれば、オーステナイト
結晶粒を微細化させ、延性及び靭性を高める作用を有す
る。この効果を確実に得るには、Vは0.05%以上の
含有量とすることが好ましい。しかし、0.4%を超え
て含有させても前記の効果は飽和し、コストが嵩むばか
りである。したがって、Vの含有量を0.4以下とし
た。
V: 0.4% or less V may not be added. If added, it has the effect of refining austenite crystal grains and increasing ductility and toughness. In order to ensure this effect, it is preferable that the content of V is 0.05% or more. However, even if the content exceeds 0.4%, the above effect is saturated and the cost is increased. Therefore, the content of V is set to 0.4 or less.

【0035】Nb:0.1%以下 Nbは添加しなくてもよい。添加すれば、オーステナイ
ト結晶粒を微細化させ、延性及び靭性を高める作用を有
する。この効果を確実に得るには、Nbは0.001%
以上の含有量とすることが好ましい。しかし、0.1%
を超えて含有させても前記の効果は飽和し、コストが嵩
むばかりである。したがって、Nbの含有量を0.1%
以下とした。
Nb: 0.1% or less Nb may not be added. If added, it has the effect of refining austenite crystal grains and increasing ductility and toughness. To ensure this effect, Nb is 0.001%
It is preferable to set the content as described above. But 0.1%
If the content exceeds the above value, the above effect is saturated and the cost is increased. Therefore, the content of Nb is 0.1%
It was as follows.

【0036】Ti:0.1%以下 Tiは添加しなくてもよい。添加すれば、オーステナイ
ト結晶粒を微細化させ、延性及び靭性を高める作用を有
する。この効果を確実に得るには、Tiは0.01%以
上の含有量とすることが好ましい。しかし、0.1%を
超えて含有させても前記の効果は飽和し、コストが嵩む
ばかりである。したがって、Tiの含有量を0.1%以
下とした。
Ti: 0.1% or less Ti need not be added. If added, it has the effect of refining austenite crystal grains and increasing ductility and toughness. To ensure this effect, it is preferable that the content of Ti be 0.01% or more. However, even if the content exceeds 0.1%, the above effect is saturated and the cost is increased. Therefore, the content of Ti is set to 0.1% or less.

【0037】Zr:0.1%以下 Zrは添加しなくてもよい。添加すれば、オーステナイ
ト結晶粒を微細化させ、延性及び靭性を高める作用を有
する。この効果を確実に得るには、Zrは0.01%以
上の含有量とすることが好ましい。しかし、0.1%を
超えて含有させても前記の効果は飽和し、コストが嵩む
ばかりである。したがって、Zrの含有量を0.1%以
下とした。
Zr: 0.1% or less Zr may not be added. If added, it has the effect of refining austenite crystal grains and increasing ductility and toughness. In order to surely obtain this effect, the content of Zr is preferably set to 0.01% or more. However, even if the content exceeds 0.1%, the above effect is saturated and the cost is increased. Therefore, the content of Zr is set to 0.1% or less.

【0038】B:0.005%以下 Bは添加しなくてもよい。添加すれば、パーライト中の
セメンタイトの成長を促進させて線材の延性を高める作
用を有する。この効果を確実に得るには、Bは0.00
03%以上の含有量とすることが好ましい。しかし、そ
の含有量が0.005%を超えると、熱間や温間での加
工時に割れが生じ易くなる。したがって、Bの含有量を
0.005%以下とした。
B: 0.005% or less B may not be added. If added, it has the effect of promoting the growth of cementite in pearlite and increasing the ductility of the wire. To ensure this effect, B should be 0.00
The content is preferably at least 03%. However, if the content exceeds 0.005%, cracks are likely to occur during hot or warm working. Therefore, the content of B is set to 0.005% or less.

【0039】P:0.05%以下 Pは伸線加工性を低下させてしまう。特にその含有量が
0.05%を超えると伸線加工性の低下が著しくなる。
したがって、Pの含有量を0.05%以下とした。
P: 0.05% or less P decreases the drawability. In particular, when the content exceeds 0.05%, the wire drawing workability is significantly reduced.
Therefore, the content of P is set to 0.05% or less.

【0040】S:0.05%以下 Sは伸線加工性を低下させてしまう。特にその含有量が
0.05%を超えると伸線加工性の低下が著しくなる。
したがって、Sの含有量を0.05%以下とした。
S: 0.05% or less S reduces the drawability. In particular, when the content exceeds 0.05%, the wire drawing workability is significantly reduced.
Therefore, the content of S is set to 0.05% or less.

【0041】希土類元素:0.10%以下 希土類元素は添加しなくてもよい。添加すれば、熱間加
工性を高める作用を有する。この効果を確実に得るに
は、希土類元素は0.002%以上の含有量とすること
が好ましい。しかし、希土類元素を0.10%を超えて
含有させても前記の効果は飽和し、コストが嵩むばかり
である。したがって、希土類元素の含有量を0.10%
以下とした。なお、本発明でいう「希土類元素の含有
量」は、「希土類元素の合計の含有量」を指す。
Rare earth element: 0.10% or less Rare earth element need not be added. If added, it has the effect of increasing hot workability. To ensure this effect, the content of the rare earth element is preferably 0.002% or more. However, even if the rare earth element is contained in an amount exceeding 0.10%, the above effect is saturated and the cost is increased. Therefore, the content of the rare earth element is 0.10%
It was as follows. The “content of the rare earth element” in the present invention indicates “the total content of the rare earth element”.

【0042】Ca:0.01%以下 Caは添加しなくてもよい。添加すれば、熱間加工性を
高める作用を有する。この効果を確実に得るには、Ca
は0.0005%以上の含有量とすることが好ましい。
しかし、Caを0.01%を超えて含有させても前記の
効果は飽和し、コストが嵩むばかりである。したがっ
て、Caの含有量を0.01%以下とした。
Ca: 0.01% or less Ca may not be added. If added, it has the effect of increasing hot workability. To ensure this effect, Ca
Is preferably 0.0005% or more.
However, even if Ca is contained in an amount exceeding 0.01%, the above-mentioned effect is saturated, and the cost is increased. Therefore, the content of Ca is set to 0.01% or less.

【0043】Mg:0.01%以下 Mgは添加しなくてもよい。添加すれば、熱間加工性を
高める作用を有する。この効果を確実に得るには、Mg
は0.0005%以上の含有量とすることが好ましい。
しかし、Mgを0.01%を超えて含有させても前記の
効果は飽和し、コストが嵩むばかりである。したがっ
て、Mgの含有量を0.01%以下とした。
Mg: 0.01% or less Mg need not be added. If added, it has the effect of increasing hot workability. To ensure this effect, use Mg
Is preferably 0.0005% or more.
However, even if Mg is contained in an amount exceeding 0.01%, the above effect is saturated and the cost is increased. Therefore, the content of Mg is set to 0.01% or less.

【0044】(B)線材の横断面における炭素含有量分
布 本発明においては、線材の外周から前記線材の半径の1
/50の深さの位置までの領域におけるC含有量の平均
値を0.6〜0.9×C%に規定する。これは、下記の
理由による。
(B) Carbon Content Distribution in the Cross Section of the Wire In the present invention, the radius of the wire from the outer periphery of the wire is 1
The average value of the C content in the region up to the position of the depth of / 50 is defined as 0.6 to 0.9 × C%. This is for the following reason.

【0045】線材を冷間で伸線加工する際の変形は、外
周部つまり表層部に近い方が大きく、特に横断面におい
て、外周から半径の1/50の深さの領域での変形が大
きい。本発明は、前記の領域の硬度を中心部の硬度より
低くして冷間での伸線加工時の変形抵抗を減少させ、伸
線加工性を高めることを大きな特徴とする。この場合、
前記領域におけるC含有量の平均値が0.9×C%を超
えれば、冷間伸線加工時の変形抵抗の減少は小さく、伸
線加工性を高めることができない。なお、「C」が「線
材のC含有量」を指すことは既に述べたとおりであり、
例えば、とりべ分析値を意味する。一方、前記領域にお
けるC含有量の平均値が0.6%未満であれば、初析フ
ェライトが析出し、伸線加工時にこの軟質な初析フェラ
イトに変形応力が集中するため限界加工度が低下するの
で、真歪量で2.60を超えるような大きな加工度で伸
線すれば断線が多発する。したがって、線材の外周から
前記線材の半径の1/50の深さの位置までの領域にお
けるC含有量の平均値を0.6〜0.9×C%とした。
The deformation at the time of cold drawing of the wire is large near the outer peripheral portion, that is, near the surface layer portion. In particular, in a cross section, the deformation is large in a region at a depth of 1/50 of the radius from the outer periphery. . The present invention is characterized in that the hardness of the above-mentioned region is made lower than the hardness of the central portion to reduce the deformation resistance at the time of cold drawing, and to enhance the drawability. in this case,
If the average value of the C content in the region exceeds 0.9 × C%, the decrease in deformation resistance during cold drawing is small, and the drawing workability cannot be improved. It is to be noted that “C” indicates “C content of wire” as already described,
For example, it means a ladle analysis value. On the other hand, if the average value of the C content in the region is less than 0.6%, pro-eutectoid ferrite precipitates and the deformation stress concentrates on this soft pro-eutectoid ferrite at the time of wire drawing. Therefore, if the wire is drawn with a large working degree such that the true strain exceeds 2.60, disconnection frequently occurs. Therefore, the average value of the C content in the region from the outer periphery of the wire to a position at a depth of 1/50 of the radius of the wire is set to 0.6 to 0.9 × C%.

【0046】なお、「線材の最外層から前記線材の半径
の1/50の深さの位置までの領域におけるC含有量の
平均値」が、例えば波長分散型の電子線マイクロアナラ
イザーを用いて線材外周部(表層部近傍)のC含有量の
線分析を行った場合の、外周から半径の4/250、3
/250、2/250及び1/250の深さの位置にお
けるC含有量の平均値を指すことは既に述べたとおりで
ある。
The "average value of the C content in the region from the outermost layer of the wire to a position at a depth of 1/50 of the radius of the wire" is calculated, for example, using a wavelength-dispersive electron beam microanalyzer. When a line analysis of the C content in the outer peripheral portion (near the surface layer portion) was performed, 4/250, 3
As described above, it indicates the average value of the C content at the depths of / 250, 2/250, and 1/250.

【0047】線材の外周から前記線材の半径の1/50
の深さの位置までの領域におけるC含有量の平均値を
0.6〜0.9×C%とするには、例えば脱炭層がほと
んどないビレットを天然ガス(主成分はメタン(CH
4 ))を燃料とする加熱炉で加熱する場合、1050〜
1100℃の温度に保持した炉内に前記のビレットを装
入して30〜40分保持し、圧延仕上げ温度を830〜
870℃として熱間圧延した後、5〜10℃/秒の冷却
速度で500℃以下の温度まで冷却すれば良い。又、ビ
レットに脱炭層がある場合には、その度合いに応じて炉
の温度と在炉時間を変更すれば良い。
1/50 of the radius of the wire from the outer circumference of the wire
In order to make the average value of the C content in the region up to the position of the depth of 0.6 to 0.9 × C%, for example, a billet having almost no decarburized layer is converted into natural gas (main component is methane (CH 2
4 ) When heating with a heating furnace using fuel,
The billet was charged into a furnace maintained at a temperature of 1100 ° C. and maintained for 30 to 40 minutes.
After hot rolling at 870 ° C., it may be cooled to a temperature of 500 ° C. or lower at a cooling rate of 5 to 10 ° C./sec. If the billet has a decarburized layer, the furnace temperature and the furnace time may be changed according to the degree of the decarburized layer.

【0048】前記(A)項に記載の化学組成と本(B)
項に記載の炭素含有量の分布を有する線材は、通常の方
法で伸線加工が施され、次いで、調質処理やブルーイン
グ処理が施されてワイヤロープ、PC鋼線などの最終製
品に仕上げられる。あるいは、通常の方法で伸線加工が
施され、次いで、最終熱処理と最終伸線が施されてビー
ドワイヤーやスチールコード用の鋼線に仕上げられる。
The chemical composition described in the above (A) and the present (B)
The wire rod having the carbon content distribution described in the section is subjected to wire drawing in the usual way, then tempering treatment and bluing treatment to finish it into final products such as wire rope and PC steel wire. Can be Alternatively, wire drawing is performed in a usual manner, and then final heat treatment and final wire drawing are performed to finish a bead wire or a steel wire for a steel cord.

【0049】以下、実施例により本発明を詳しく説明す
る。
Hereinafter, the present invention will be described in detail with reference to examples.

【0050】[0050]

【実施例】表1に示す化学組成を有する鋼A〜Mを15
0kg真空炉を用いて溶製した。表1における鋼A〜
C、E、G、I、L及びMは化学組成が本発明で規定す
る含有量の範囲内にある本発明例である。一方、鋼D、
F、H、J及びKは成分のいずれかが本発明で規定する
含有量の範囲から外れた比較例である。
EXAMPLE Steels A to M having the chemical compositions shown in Table 1 were used for 15 samples.
It was melted using a 0 kg vacuum furnace. Steel A to Table 1
C, E, G, I, L, and M are examples of the present invention in which the chemical composition is within the range defined by the present invention. On the other hand, steel D,
F, H, J and K are comparative examples in which any one of the components is out of the range of the content specified in the present invention.

【0051】[0051]

【表1】 [Table 1]

【0052】次いで、これらの鋼を通常の方法で熱間鍛
造して直径60mmの丸棒にし、次いで、直径50mm
まで機械研削して脱炭層を完全に除去した。この後、上
記の直径50mmの丸棒を6等分し、加熱炉中の雰囲気
を制御しながら1050℃で30分間加熱し、通常の方
法で熱間圧延し、直径5.5mm又は10mmの線材に
した。なお、熱間圧延した各線材はパーライト組織を主
とするものであった。
Next, these steels were hot-forged in a usual manner into round bars having a diameter of 60 mm,
The decarburized layer was completely removed by mechanical grinding. Thereafter, the above-mentioned round bar having a diameter of 50 mm is divided into six equal parts, heated at 1050 ° C. for 30 minutes while controlling the atmosphere in a heating furnace, and hot-rolled by a usual method to obtain a wire rod having a diameter of 5.5 mm or 10 mm. I made it. Each of the hot-rolled wires mainly had a pearlite structure.

【0053】なお、熱間圧延前の加熱には電気炉を用
い、炉中雰囲気はCO、H2、N2及びCO2で構成し、
(COの分圧)2/(CO2 の分圧)を変えることで、
外周部のC含有量を調整した。
An electric furnace was used for heating before hot rolling, and the atmosphere in the furnace was composed of CO, H 2 , N 2 and CO 2 .
By changing (partial pressure of CO) 2 / (partial pressure of CO 2 ),
The C content in the outer peripheral portion was adjusted.

【0054】熱間圧延線材から横断サンプルを採取し、
その外周部(表層部近傍)のC含有量を測定した。すな
わち、波長分散型の電子線マイクロアナライザーを用い
て、C量の線分析を行い、外周から半径の4/250、
3/250、2/250及び1/250の深さの位置で
のC含有量を測定チャートから読み取り、この4点の平
均値を求めることで、外周から半径の1/50の深さの
位置までの領域におけるC含有量の平均値を得た。図1
に、外周部(表層部近傍)のC含有量の一例として、後
述の表2の試験番号8における測定結果を示す。なお、
この図でA=0.65%としたのが上記のC含有量の平
均値である。
A transverse sample was taken from the hot rolled wire rod,
The C content in the outer peripheral portion (near the surface layer portion) was measured. That is, using a wavelength-dispersion type electron beam microanalyzer, a line analysis of the amount of C was performed, and 4/250 of the radius from the outer periphery was obtained.
The C content at the depths of 3/250, 2/250, and 1/250 is read from the measurement chart, and the average value of these four points is obtained, whereby the position at a depth of 1/50 of the radius from the outer circumference is obtained. The average value of the C content in the region up to was obtained. FIG.
Table 2 shows the measurement results of Test No. 8 in Table 2 described below as an example of the C content in the outer peripheral portion (near the surface layer portion). In addition,
In this figure, A = 0.65% is the average value of the above-mentioned C content.

【0055】前記のようにして得た熱間圧延線材を通常
の方法で酸洗し、潤滑剤を塗布した後、各ダイスでの減
面率が平均で20%となるパススケジュールで、断線す
るまで伸線加工を行った。この際、真歪で2.60以上
の伸線加工を行っても断線しない場合に、伸線加工性が
良好であると評価した。
The hot-rolled wire obtained as described above is pickled by a usual method, coated with a lubricant, and then cut by a pass schedule in which the area reduction rate in each die is 20% on average. Wire drawing was carried out. At this time, when the wire was not broken even when the wire was drawn at a true strain of 2.60 or more, the wire drawing was evaluated to be good.

【0056】表2及び表3に、加熱炉雰囲気条件、熱間
圧延した線材のサイズ及び前記の各調査結果をまとめて
示す。なお、表2及び表3において、加熱炉の雰囲気条
件は条件1から5の順に、(COの分圧)2/(CO2
分圧)が120、60、30、15、5であることを示
す。
Tables 2 and 3 collectively show the atmosphere conditions of the heating furnace, the size of the hot-rolled wire, and the results of the above-mentioned investigations. In Tables 2 and 3, the atmosphere conditions of the heating furnace should be (partial pressure of CO) 2 / (partial pressure of CO 2 ) of 120, 60, 30, 15, and 5 in the order of conditions 1 to 5. Is shown.

【0057】[0057]

【表2】 [Table 2]

【0058】[0058]

【表3】 [Table 3]

【0059】表2及び表3から明らかなように、比較例
の鋼D、F、H、J及びKを用いた試験番号の場合、つ
まり、C含有量が1.1%を超える試験番号16〜2
0、Si含有量が1.5%を超える試験番号26〜3
0、Mn含有量が1.0%を超える試験番号36〜4
0、Cr含有量が1.0%を超える試験番号46〜5
0、N含有量が0.006%を超える試験番号51〜5
5は、伸線加工性が低く、真歪量2.60に達せずに断
線を生じた。上記のうち試験番号16、26、36、4
6、47及び51は、外周から半径の1/50の深さの
位置までの領域におけるC含有量の平均値が0.9×C
%を超えるため、伸線加工性は極めて劣る。又、試験番
号20、30、40及び55は、外周から半径の1/5
0の深さの位置までの領域におけるC含有量の平均値が
0.6%を下回るため、線材表層部に初析フェライトが
生成し、伸線加工性は極めて劣る。
As is clear from Tables 2 and 3, in the case of the test numbers using the steels D, F, H, J and K of the comparative examples, that is, test number 16 in which the C content exceeds 1.1%. ~ 2
0, Test No. 26-3 with Si content exceeding 1.5%
0, Test No. 36-4 with Mn content exceeding 1.0%
0, Test No. 46 to 5 with Cr content exceeding 1.0%
Test Nos. 51 to 5 with 0, N content exceeding 0.006%
In No. 5, the wire drawing workability was low, and the true strain amount did not reach 2.60, and the wire was broken. Test numbers 16, 26, 36, 4
6, 47 and 51 have an average C content of 0.9 × C in a region from the outer circumference to a position at a depth of 1/50 of the radius.
%, The drawability is extremely poor. Test numbers 20, 30, 40, and 55 are 1/5 of the radius from the outer circumference.
Since the average value of the C content in the region up to the position of the depth of 0 is less than 0.6%, proeutectoid ferrite is generated in the surface layer portion of the wire, and the drawability is extremely poor.

【0060】化学組成が本発明で規定する含有量の範囲
内にある鋼であっても、試験番号1、6、7、11、2
1、31、41、42、56、57及び61は、外周か
ら半径の1/50の深さの位置までの領域におけるC含
有量の平均値が0.9×C%を超えるため、伸線加工性
が低く、真歪量2.60に達せずに断線を生じた。
Even if the steel has a chemical composition within the range specified in the present invention, test numbers 1, 6, 7, 11, 2
1, 31, 41, 42, 56, 57, and 61 are drawn since the average value of the C content in the region from the outer periphery to a position at a depth of 1/50 of the radius exceeds 0.9 × C%. The workability was low, and the disconnection occurred without reaching the true strain of 2.60.

【0061】又、化学組成が本発明で規定する含有量の
範囲内にある鋼であっても、試験番号4、5、10、1
4、15、25、34、35、60及び65は、外周か
ら半径の1/50の深さの位置までの領域におけるC含
有量の平均値が0.6%を下回るため、線材表層部に初
析フェライトが生成し、したがって、伸線加工性が低
く、真歪量2.60に達せずに断線を生じた。
In addition, even if the steel has a chemical composition within the range specified in the present invention, test numbers 4, 5, 10, 1
Nos. 4, 15, 25, 34, 35, 60 and 65 show that the average value of the C content in the region from the outer periphery to a position at a depth of 1/50 of the radius is less than 0.6%, Proeutectoid ferrite was formed, and therefore, the wire drawing workability was low, and the wire was broken without reaching the true strain of 2.60.

【0062】上記の比較例に対し、本発明で規定する条
件を満たす本発明例の場合には、伸線加工性が良好であ
り、真歪量で2.60を超えて伸線加工しても断線を生
じなかった。
In contrast to the above comparative example, in the case of the present invention which satisfies the conditions defined in the present invention, the wire drawing workability was good, and the true strain exceeded 2.60. No disconnection occurred.

【0063】[0063]

【発明の効果】本発明の線材は伸線加工性に優れるの
で、この線材を素材としてワイヤロープ、ばね、PC鋼
線、ビードワイヤー、スチールコードなどを高い生産性
の下に歩留り良く提供することができる。この線材は通
常の設備によって比較的容易に製造でき、特別な設備を
必要としないので、その製造コストは低い。
Since the wire of the present invention is excellent in wire drawing workability, it is possible to provide a wire rope, a spring, a PC steel wire, a bead wire, a steel cord, and the like with high yield with high productivity by using the wire as a material. Can be. This wire is relatively easy to manufacture with ordinary equipment and does not require special equipment, so its manufacturing cost is low.

【図面の簡単な説明】[Brief description of the drawings]

【図1】波長分散型電子線マイクロアナライザーによる
線材横断面のC含有量の測定結果の一例を示す図であ
る。
FIG. 1 is a view showing an example of a measurement result of a C content in a cross section of a wire rod by a wavelength dispersion type electron beam microanalyzer.

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】重量%で、C:0.7〜1.1%、Si:
0.1〜1.5%、Mn:0.2〜1.0%、Cr:
1.0%以下、Al:0.05%以下、N:0.006
%以下、Cu:1.0%以下、Ni:2.0%以下、M
o:0.5%以下、Co:4.0%以下、V:0.4%
以下、Nb:0.1%以下、Ti:0.1%以下、B:
0.005%以下、P:0.05%以下、S:0.05
%以下、希土類元素:0.10%以下、Ca:0.01
%以下、Mg:0.01%以下を含有し、残部はFe及
び不可避不純物からなる鋼線材の横断面において、外周
から前記鋼線材の半径の1/50の深さの位置までの領
域におけるC含有量の平均値が0.6〜0.9×C%
(但し、Cは鋼線材のC含有量)であることを特徴とす
る伸線加工性に優れた鋼線材。
(1) C: 0.7 to 1.1% by weight, Si:
0.1-1.5%, Mn: 0.2-1.0%, Cr:
1.0% or less, Al: 0.05% or less, N: 0.006
% Or less, Cu: 1.0% or less, Ni: 2.0% or less, M
o: 0.5% or less, Co: 4.0% or less, V: 0.4%
Hereinafter, Nb: 0.1% or less, Ti: 0.1% or less, B:
0.005% or less, P: 0.05% or less, S: 0.05
% Or less, rare earth element: 0.10% or less, Ca: 0.01
%, Mg: 0.01% or less, with the balance being C in the region from the outer periphery to a position at a depth of 1/50 of the radius of the steel wire in the cross section of the steel wire made of Fe and unavoidable impurities. The average value of the content is 0.6 to 0.9 × C%
(Where C is the C content of the steel wire), wherein the steel wire is excellent in wire drawing workability.
【請求項2】重量%で、C:0.7〜1.1%、Si:
0.1〜1.5%、Mn:0.2〜1.0%、Cr:
1.0%以下、Al:0.05%以下、N:0.006
%以下、Cu:1.0%以下、Ni:2.0%以下、M
o:0.5%以下、W:0.5%以下、Co:4.0%
以下、V:0.4%以下、Nb:0.1%以下、Ti:
0.1%以下、Zr:0.1%以下、B:0.005%
以下、P:0.05%以下、S:0.05%以下、希土
類元素:0.10%以下、Ca:0.01%以下、M
g:0.01%以下を含有し、残部はFe及び不可避不
純物からなる鋼線材の横断面において、外周から前記鋼
線材の半径の1/50の深さの位置までの領域における
C含有量の平均値が0.6〜0.9×C%(但し、Cは
鋼線材のC含有量)であることを特徴とする伸線加工性
に優れた鋼線材。
2. C .: 0.7 to 1.1% by weight, Si:
0.1-1.5%, Mn: 0.2-1.0%, Cr:
1.0% or less, Al: 0.05% or less, N: 0.006
% Or less, Cu: 1.0% or less, Ni: 2.0% or less, M
o: 0.5% or less, W: 0.5% or less, Co: 4.0%
Hereinafter, V: 0.4% or less, Nb: 0.1% or less, Ti:
0.1% or less, Zr: 0.1% or less, B: 0.005%
Hereinafter, P: 0.05% or less, S: 0.05% or less, rare earth element: 0.10% or less, Ca: 0.01% or less, M
g: 0.01% or less, with the balance being the C content in the region from the outer circumference to a position at a depth of 1/50 of the radius of the steel wire in the cross section of the steel wire made of Fe and unavoidable impurities. A steel wire excellent in wire drawability, wherein the average value is 0.6 to 0.9 × C% (where C is the C content of the steel wire).
JP26982298A 1998-08-12 1998-09-24 Steel wire with excellent wire drawing workability Expired - Fee Related JP3536684B2 (en)

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JP10-227872 1998-08-12
JP22787298 1998-08-12
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