JPS6157891B2 - - Google Patents
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- Publication number
- JPS6157891B2 JPS6157891B2 JP19196581A JP19196581A JPS6157891B2 JP S6157891 B2 JPS6157891 B2 JP S6157891B2 JP 19196581 A JP19196581 A JP 19196581A JP 19196581 A JP19196581 A JP 19196581A JP S6157891 B2 JPS6157891 B2 JP S6157891B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- wire drawing
- steel
- wire
- less
- 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
Links
- 238000000034 method Methods 0.000 claims description 43
- 239000000463 material Substances 0.000 claims description 34
- 229910000831 Steel Inorganic materials 0.000 claims description 30
- 239000010959 steel Substances 0.000 claims description 30
- 238000013000 roll bending Methods 0.000 claims description 19
- 238000004804 winding Methods 0.000 claims description 8
- 229910052799 carbon Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 229910000851 Alloy steel Inorganic materials 0.000 claims description 5
- 238000005491 wire drawing Methods 0.000 description 48
- 206010037660 Pyrexia Diseases 0.000 description 30
- 238000010438 heat treatment Methods 0.000 description 28
- 230000008569 process Effects 0.000 description 23
- 238000000137 annealing Methods 0.000 description 13
- 238000005461 lubrication Methods 0.000 description 11
- 238000005452 bending Methods 0.000 description 10
- 238000005554 pickling Methods 0.000 description 10
- 230000000694 effects Effects 0.000 description 7
- 150000001247 metal acetylides Chemical class 0.000 description 5
- 239000002994 raw material Substances 0.000 description 5
- 238000007796 conventional method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 102200082816 rs34868397 Human genes 0.000 description 4
- 238000005482 strain hardening Methods 0.000 description 3
- 238000010273 cold forging Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000005485 electric heating Methods 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Description
〔産業上の利用分野〕
ボルト、自動車用機械部品等に用いられる冷間
鍛造用鋼棒鋼線は、冷間鍛造性の向上を図るた
め、鋼中炭化物の球状化処理を施すことが多い。
具体的にはJISG4051〜G4052、G4102〜4108、
G4202、G4805、G4403、G4805、G4301等に規定
される炭素量が1.5%以下の中・低合金鋼の棒材
線材が球状化処理の対象となつている。本発明
は、このような球状化処理の対象となる炭素量
1.5%以下の中・低合金鋼からなる鋼棒鋼線用素
材の、鋼中炭化物の球状化処理の改良に関する。
〔従来の技術〕
この球状化処理は従来、次の方法によつて行わ
れていた。第1図は従来の球状化処理方法の一例
を示した説明図で、1は素材コイル、2は酸洗装
置、3は潤滑処理装置、4はダイス伸線装置、5
は球状化焼鈍炉である。
素材コイル1は酸洗装置でデスケール及び脱炭
防止処理を施された後、潤滑処理装置に搬送さ
れ、潤滑処理を施された後、アンコイラー6で巻
戻しされダイス7で所望の寸法(径)に伸線され
ると共に球状化性の向上が図られ、コイラー8に
巻取られた後、球状化焼鈍炉5に搬送され、球状
化焼鈍処理を施される。この従来方法は、各工程
毎にコイル単位で処理されるいわゆるバツチ式で
あり、次の〜の欠点がある。
〔発明が解決しようとする問題点〕
工程が複数であるため生産性が低く、従つて
コスト高となる。
工程中の仕掛品が多く、管理に手間がかかる
うえに、運搬などでの疵発生のトラブルが起こ
り易い。
球状化焼鈍には数時間乃至20数時間の極めて
長時間を要し、多大のコストがかかる。
酸洗による公害対策を要する。
一方、前記従来方法の他に、高度の冷間鍛造性
を要求されない用途向に対して、潤滑、ダイス伸
線の工程を省略して、酸洗した素材コストを直ち
に焼鈍処理する簡単な方法もあるが、この方法で
は圧延素材径により製品径が制約される欠点が加
わるばかりでなく、上記の欠点は何等解消され
ない。また酸洗に代えてメカニカルデスケーラー
を用い、メカニカルデスケーラー→潤滑→ダイス
伸線の工程をインラインで連続的に処理する方法
が開発されているが、球状化焼鈍による上記の
欠点は依然残る。
本発明は、従来方法の上記4つの欠点をすべて
解消すべくなされたもので、従来方法における酸
洗、潤滑の両工程を省略するとともに、ダイスに
よる伸縮ををロールベンデイング装置にかえて、
前処理工程を含めた球状化処理工程全体を簡略化
するとともに、インラインで連続的に球状化処理
して処理時間を大幅に短縮させ、コストの低減を
図ることを目的とする。
〔問題点を解決するための手段〕
本発明者らは、球状化処理に関して種々実験研
究の結果、鋼にA3変態点以下の温度域で塑性変
形を加えると、鋼中炭化物の30〜50%が球状化
し、さらにその温度に短時間保持することにより
炭化物のほとんど全部が球状化するという新事実
の知見を得、この知見に基づいて球状化処理時間
の短縮を図るとともに、処理工程全体をインライ
ンで連続化した本発明方法を完成するに至つたも
のである。
すなわち本発明は、
(1) 鋼棒鋼線用素材を、350℃以上850℃以下の温
度に加熱してその温度域でロールベンデイング
装置により伸び率5%以上の伸びを与え、ひき
つづきコイラーに巻取り前または巻取り後に
450℃以上750℃以下の温度で2分以上保持する
処理を連続して実施する鋼棒鋼線の連続球状化
処理方法。
(2) 鋼棒鋼線用素材を予め冷間でロールベンデイ
ング装置により適当な伸びを与え、さらに350
℃以上850℃以下の温度に加熱してその温度域
でロールベンデイング装置により伸び率5%以
上の伸びを与え、ひきつづきコイラーに巻取り
前または巻取り後に450℃以上750℃以下の温度
で2分以上保持する処理を連続して実施する鋼
棒鋼線の連続球状化処理方法。
を骨子とするものである。
以下図面に基づいて、本発明を詳細に説明す
る。
第2図は本発明方法を施する鋼線の球状化処理
ラインの説明図である。本発明方法ではアンコイ
ラー11から連続的に送り出される鋼線素材10
は、冷間伸線工程12を経てまたは経ないでアン
コイラー11から直接、加熱工程13、温間伸線
工程14、保温処理工程15を順次通過して球状
化処理を施された後コイラー16に巻取られる。
まず冷間伸線工程12について説明する。
一般に焼鈍前に予め素材を冷間伸線すること
は、球状化焼鈍処理をより一層高めるために有効
とされており、従来はダイス伸線が行われていた
が、ダイス伸線は前処理として素材の酸洗潤滑を
要し、コスト高となるとともにインライン化が困
難であつた。そこで本発明の冷間伸線工程12に
は複数個のロール17をライン上に配列したロー
ルベンデイング装置による伸線を用いた。ロール
ベンデイング装置の伸線には、上記如き素材の潤
滑処理を必要とせずまた伸線と同時にデスケーリ
ングが可能であるため、酸洗等の前処理を要しな
いで熱延素材をそのまま伸線できる利点があつて
コストを大幅に低減できる。また伸線径がロール
の圧下量で変えられるため、インラインあるいは
走間にて線径の変更が可能であり、伸線のインラ
イン連続処理に最も適している。
この冷間伸線工程12における伸び率は、球状
化焼鈍効果を向上させる観点から5%以上が適当
であり、この範囲内で伸びが大きい程、球状化の
効果があるが、現実には鋼線素材の変形能や加工
硬化能に当然制約される。すなわち、一般に冷間
伸線工程ではロールベンデイング装置と引抜き駆
動装置の1セツトの組合わせからなる1ユニツト
あたりの伸び率付与の最大値は、素材の変形能や
加工硬化能による制約から、炭素量1.5%以下の
中・低合金鋼の場合で75%であり、この1セツト
の組合わせからなるユニツトを複数タンデムにラ
インに組み込んだとしても95%の伸びが限界とな
り、現実にはこの95%が伸び率の上限となる。
なお、この冷間伸線工程12は、特に高度の球
状化を要しない用途向で実用可能な程度の鋼線を
得ようとする場合には、省略しても差し支えな
い。
加熱工程13においては、素材を350℃以上850
℃以下、好ましくは500℃以上750℃以下、の温度
に加熱する。加熱温度を上記の如く限定したの
は、上記温度域で伸線が行われる次の温間伸線工
程において、成分がC0.1〜0.55%の主要な冷間鍛
造用素材の場合に、850℃を越えるとA3変態点を
越えてしまい、鋼中炭化物が固溶するため球状化
作用が期待できなくなり、また350℃未満では鋼
中炭素の拡散速度が遅くなり、短時間の球状化が
不可能になるからである。加熱の方法はライン速
度が低い場合には、トンネル炉による雰囲気加熱
が使用可能であるが、ライン速度が高速の場合
は、高周波誘導加熱または直接通電加熱が適して
いる。直接通電加熱の場合は、予め表面スケール
を除去しておく必要があるので、デスケーリング
工程との組合わせを要する。
温間伸線工程14における素材の伸線は、前述
した冷間伸線におけると同様に、ロールベンデイ
ング装置によつて行われる。加熱工程で上記温度
に加熱された素材10は、直ちにロールベンデイ
ング装置に通し、上記温度域の高温状態で伸線さ
れる。この温間伸線によつて、高中炭化物の30〜
50%が球状化される。この温間伸線における伸び
率を5%以上と限定したのは、5%未満では素材
のデスケーリングが不十分であり、且つ、伸線に
よる球状化促進の効果が不十分であるからであ
る。また最大値は冷間伸線工程で述べたと同様
に、素材の変形能や加工硬化能に制約される範囲
内で大きい程、好ましいが現実には95%の伸び率
が上限となる。また温間伸線工程14にロールベ
ンデイング装置を採用したのは、高温下では潤滑
処理が困難であるため、ダイス伸線は採用できな
いが、ロールベンデイング装置の場合は無潤滑で
伸線加工が可能であるからである。
保温処理工程15においては、上記温間伸線工
程14で一部球状化された素材の鋼中炭化物を、
保温によつてさらに球状化の促進を図るものであ
る。保温処理装置は、内部の熱放散を防止するよ
う、周囲を断熱材料で囲んだ通常の保熱炉が用い
られ、炉内に装入された高温素材の自己保有熱で
所要温度に保温するものであるが、インラインで
保温する場合で、保温終了温度が低下するおそれ
がある場合は、補助加熱源(図示せず)の使用が
望ましい。
素材の保温処理は、450℃以上750℃以下、好ま
しくは600℃以上720℃以下の温度で2分以上、好
ましくは7分以上、保持して行われる。実際の素
材の保温開始温度は、温間伸線工程14の出口温
度であるが、前記温度が低い場合でも保温終了温
度を450℃以上とすればよい。
保温温度を上記の如く限定したのは、素材が高
温で加熱状態にあるときには、750℃を越えると
鋼中炭化物の溶解が迫り、球状化が行われなくな
り、また450℃未満では、鋼中炭素の拡散速度が
遅くなり、短時間の球状化が不可能になるからで
ある。また上記温度域での保持時間を2分以上限
定したのは、2分未満では球状化の進行が不十分
であるからである。また冷間伸線工程12のない
場合は、球状化の速度が若干遅くなるので7分以
上の保持時間が望ましい。保持時間の上限につい
ては、通常の焼鈍では10時間以上100時間以下の
加熱保持が行われるが、本発明では上述のように
短時間で効果的な焼鈍が行われ、10時間を超える
加熱保持は熱経済的に好ましくない。
保温の方法には2種類あつて、一つは図示例の
ようにコイラー16に巻取り前にインラインの保
熱炉15内を所要時間かけて通過させる方法と他
の一つはコイラーに巻取り後の素材コイルを保熱
炉内に装入して所要時間保持する方法であるが、
いずれも保温による球状化促進の効果は同じであ
る。
〔実施例〕
次に実施例を揚げて本発明法の効果を説明す
る。
試験例 1
材質がS45C、線径11.0mmφの線材の熱延素材
を、高周波加熱装置を通して加熱した後、直ちに
ロールベンデイング装置を通してベンデイング伸
線を行い、ひきつづいて保熱炉内のコイラーに巻
取つて保熱する球状化処理を行つた。この処理に
おける加熱、伸線、保熱の条件は次の通りであ
る。
1 高周波加熱
加熱温度:300℃〜900℃
2 温間ベンデイング伸線
ロール径:90mmφ、ピツチ:130mm
ロール数:水平方向5個、垂直方向5個
入口線温:700℃、出口線温:680℃
付与伸び率:5%〜55%
3 保熱炉
炉内温度:700℃、コイラー径:800mmφ
保熱時間:コイラー巻取り後2分〜120分
雰囲気ガス:N2ガス
試験例 2
材質がS45C、線径11.0mmφの線材の熱延素材
を、高周波加熱装置を通して加熱した後、直ちに
ロールベンデイング装置を通してベンデイング伸
線を行い、ひきつづいてトンネル炉内を通して保
熱した後、炉外でコイラーに巻取る球状化処理を
行つた。この処理における加熱、伸線、保熱の条
件は次の通りである。
1 高周波加熱
加熱温度:700℃
2 温間ベンデイング伸線
ロール径:90mmφ、ピツチ:130mm
ロール数:水平方向5個、垂直方向5個
入口線温:700℃、出口線温:680℃
付与伸び率:55%
3 保熱炉
炉内温度:700℃
通過時間:7分
雰囲気ガス:N2ガス
試験例 3
材質がSCM435、SCr435、線径12.7mmφの線材
の熱延素材を、冷間でロールベンデイング装置を
通してデスケーリングした後、通電加熱装置で加
熱し、直ちにロールベンデイング装置を通して温
間ベンデイング伸線を行い、ひきつづいて保熱炉
内のコイラーに巻取つて保熱する球状化処理を行
つた。この処理における加熱、伸線保熱の条件は
次の通りである。
1 冷間ベンデイング伸線
付与伸び率:25%
2 通電加熱
加熱温度:700℃
3 温間ベンデイング伸線
ロール径:90mmφ、ピツチ:130mm
ロール数:水平方向5個、垂直方向5個
入口線温:700℃、出口線温:680℃
付与伸び率:55%
4 保熱炉
炉内温度:690℃、コイラー径:800mmφ
保熱時間:コイラー巻取り後15分
雰囲気ガス:N2ガス
試験例 4
材質がS45C、線径12.7mmφの線材の熱延素材
を、冷間でロールベンデイング装置を通してデス
ケーリングした後、通電加熱装置で加熱し、直ち
にロールベンデイング装置を通して温間ベンデイ
ング伸線を行い、ひきつづいてトンネル炉内を通
して保熱した後、炉外でコイラーに巻取る球状化
処理を行つた。この処理における加熱、伸線、保
熱の条件は次の通りである。
1 冷間ベンデイング伸線、
付与伸び率:25%
2 通電加熱
加熱温度:700℃
3 温間ベンデイング伸線
ロール径:90mmφ、ピツチ:130mm
ロール数:水平方向5個、垂直方向5個
入口線温:700℃、出口線温:680℃
付与伸び率:55%
4 保熱炉
炉内温度:690℃
保熱時間:7分
雰囲気ガス:N2ガス
上記試験例1乃至試験例4による各条件で、イ
ンラインで連続的に各種の線材の熱延素材に球状
化処理を施して27例の試験材を製造した。また比
較のため、材質がS45C、線径90mmφの線材の熱
延素材を酸洗、潤滑の両工程を経て、ダイスによ
る7.37mmφとした後、750℃まで3.75時間昇温、
750℃で3時間保持、ひきつづいて10℃/Hで550
℃に降温、以後放冷の、所要時間26.65時間の球
状化焼鈍する通常の方法による球状化処理を行い
従来例とした。
[Industrial Application Fields] Steel bars and wires for cold forging used for bolts, automobile machine parts, etc. are often treated to make the carbides in the steel spheroidized in order to improve cold forgeability.
Specifically, JISG4051~G4052, G4102~4108,
Medium- and low-alloy steel rods and wire rods with a carbon content of 1.5% or less as specified by G4202, G4805, G4403, G4805, G4301, etc. are subject to spheroidization treatment. The present invention aims at reducing the amount of carbon to be subjected to such spheroidization treatment.
This paper relates to improvements in the spheroidization treatment of carbides in steel for steel bars and wires made of medium- to low-alloy steel with a content of 1.5% or less. [Prior Art] Conventionally, this spheroidizing treatment has been carried out by the following method. FIG. 1 is an explanatory diagram showing an example of a conventional spheroidization treatment method, in which 1 is a raw material coil, 2 is a pickling device, 3 is a lubrication treatment device, 4 is a die wire drawing device, and 5
is a spheroidizing annealing furnace. The raw material coil 1 is descaled and decarburized in a pickling device, then transported to a lubrication device, where it is lubricated, unwound in an uncoiler 6, and cut into a desired size (diameter) by a die 7. The wire is drawn to improve its spheroidizing properties, and after being wound around a coiler 8, it is transported to a spheroidizing annealing furnace 5, where it is subjected to a spheroidizing annealing process. This conventional method is a so-called batch method in which each coil is processed in each step, and has the following drawbacks. [Problems to be solved by the invention] Since there are multiple steps, productivity is low and costs are therefore high. There are many work-in-progress items in the process, which requires time and effort to manage, and problems such as defects during transportation are likely to occur. Spheroidizing annealing takes an extremely long time, ranging from several hours to over 20 hours, and is costly. Pollution countermeasures by pickling are required. On the other hand, in addition to the above-mentioned conventional method, for applications that do not require a high level of cold forgeability, there is also a simple method in which the pickled material cost is immediately annealed, omitting the lubrication and die wire drawing steps. However, this method not only has the disadvantage that the product diameter is limited by the diameter of the rolled material, but also does not solve the above-mentioned disadvantages in any way. In addition, a method has been developed in which a mechanical descaler is used instead of pickling and the steps of mechanical descaler → lubrication → die wire drawing are performed continuously in-line, but the above-mentioned drawbacks due to spheroidizing annealing still remain. The present invention was made to eliminate all of the above-mentioned four drawbacks of the conventional method, and it eliminates both the pickling and lubrication steps in the conventional method, and replaces the expansion and contraction using a die with a roll bending device.
The purpose is to simplify the entire spheroidization process including the pretreatment process, and to significantly shorten processing time and reduce costs by performing continuous spheroidization processing in-line. [Means for Solving the Problem] As a result of various experimental studies regarding spheroidization treatment, the present inventors found that when plastic deformation is applied to steel in a temperature range below the A3 transformation point, 30 to 50% of the carbides in the steel are % of the carbide becomes spheroidized, and by holding it at that temperature for a short time, almost all of the carbide becomes spheroidized. Based on this knowledge, we aim to shorten the spheroidization treatment time and improve the overall processing process. This has led to the completion of the in-line continuous method of the present invention. That is, the present invention provides the following features: (1) The material for steel bars and wires is heated to a temperature of 350°C or higher and 850°C or lower, elongated to an elongation rate of 5% or more using a roll bending device in that temperature range, and then wound on a coiler. Before or after winding
A method for continuous spheroidization of steel bars and wires, in which a process is continuously carried out at a temperature of 450°C or higher and 750°C or lower for 2 minutes or more. (2) The material for steel rods and wires is given an appropriate elongation in advance by cold roll bending equipment, and further
Heat to a temperature of ℃ to 850℃, elongate the elongation rate to 5% or more using a roll bending device in that temperature range, and then apply it to a coiler at a temperature of 450℃ to 750℃ before or after winding. A method for continuous spheroidization of steel bars and wires, in which a process is continuously carried out to hold the steel wire for more than 1 minute. The main points are as follows. The present invention will be explained in detail below based on the drawings. FIG. 2 is an explanatory diagram of a steel wire spheroidization treatment line in which the method of the present invention is applied. In the method of the present invention, the steel wire material 10 is continuously fed out from the uncoiler 11.
The wire is directly sent from the uncoiler 11 with or without passing through the cold wire drawing step 12, passed through a heating step 13, a warm wire drawing step 14, and a heat retention treatment step 15 in order to undergo a spheroidization treatment, and then transferred to a coiler 16. It is wound up. First, the cold wire drawing step 12 will be explained. Generally, cold wire drawing of the material before annealing is considered effective for further enhancing the spheroidizing annealing process, and conventionally die wire drawing was performed, but die wire drawing is used as a pretreatment. It required pickling and lubrication of the material, which increased costs and made it difficult to implement in-line. Therefore, in the cold wire drawing step 12 of the present invention, wire drawing using a roll bending device in which a plurality of rolls 17 are arranged on a line is used. Wire drawing using roll bending equipment does not require the above-mentioned lubrication treatment of the material, and descaling can be performed at the same time as wire drawing, so hot-rolled material can be drawn as is without the need for pretreatment such as pickling. This has the advantage of being able to significantly reduce costs. Furthermore, since the wire drawing diameter can be changed by the amount of reduction of the rolls, the wire diameter can be changed in-line or between runs, making it most suitable for in-line continuous wire drawing processing. The elongation rate in this cold wire drawing step 12 is suitably 5% or more from the viewpoint of improving the spheroidizing annealing effect, and within this range, the larger the elongation, the more spheroidizing effect. Naturally, this is limited by the deformability and work hardening ability of the wire material. In other words, in general, in the cold wire drawing process, the maximum elongation rate per unit consisting of a combination of a roll bending device and a drawing drive device is limited by the deformability and work hardening ability of the material. In the case of medium and low alloy steel with a content of 1.5% or less, the elongation is 75%, and even if multiple units consisting of this one set are installed in a line in tandem, the limit is 95% elongation, and in reality, this 95% % is the upper limit of the growth rate. Note that this cold wire drawing step 12 may be omitted especially when attempting to obtain a practically usable steel wire for applications that do not require a high degree of spheroidization. In heating step 13, the material is heated to 350°C or higher at 850°C.
It is heated to a temperature of 500°C or higher and 750°C or lower, preferably 500°C or higher and 750°C or lower. The reason why the heating temperature is limited as above is that in the next warm wire drawing process where wire drawing is performed in the above temperature range, 850 If the temperature exceeds 350°C, the A3 transformation point will be exceeded, and the carbides in the steel will form a solid solution, so no spheroidizing effect can be expected.If the temperature is below 350°C, the diffusion rate of carbon in the steel will slow down, resulting in short-term spheroidization. Because it becomes impossible. As for the heating method, when the line speed is low, atmospheric heating using a tunnel furnace can be used, but when the line speed is high, high frequency induction heating or direct current heating is suitable. In the case of direct current heating, it is necessary to remove surface scale in advance, so it must be combined with a descaling process. The wire drawing of the raw material in the warm wire drawing step 14 is performed by a roll bending device as in the cold wire drawing described above. The raw material 10 heated to the above temperature in the heating process is immediately passed through a roll bending device and drawn at a high temperature in the above temperature range. Through this warm wire drawing, high to medium carbide
50% spheroidized. The elongation rate in this warm wire drawing was limited to 5% or more because if it is less than 5%, the descaling of the material is insufficient and the effect of promoting spheroidization by wire drawing is insufficient. . Further, as described in the cold wire drawing process, the larger the maximum value is, the better within the range limited by the deformability and work hardening ability of the material, but in reality, the upper limit is 95% elongation. In addition, a roll bending device was used in the warm wire drawing process 14 because it is difficult to lubricate at high temperatures, so die wire drawing cannot be used, but in the case of a roll bending device, wire drawing can be performed without lubrication. This is because it is possible. In the heat retention treatment step 15, carbide in steel, which is a material partially spheroidized in the warm wire drawing step 14, is
The purpose is to further promote spheroidization by keeping warm. Heat retention treatment equipment uses a regular heat retention furnace surrounded by insulating material to prevent internal heat dissipation, and uses the self-retained heat of the high-temperature material charged in the furnace to maintain the temperature at the required temperature. However, in the case of in-line heat retention, if there is a risk that the end temperature of the heat retention may decrease, it is desirable to use an auxiliary heating source (not shown). The heat retention treatment of the material is carried out by holding the material at a temperature of 450° C. or higher and 750° C. or lower, preferably 600° C. or higher and 720° C. or lower, for 2 minutes or more, preferably 7 minutes or more. The actual heat retention start temperature of the material is the exit temperature of the warm wire drawing step 14, but even if the temperature is low, the heat retention end temperature may be set to 450° C. or higher. The reason why the heat retention temperature is limited as above is that when the material is heated at a high temperature, if the temperature exceeds 750℃, the carbides in the steel will melt and spheroidization will not occur, and if the temperature is lower than 450℃, the carbon in the steel will melt. This is because the diffusion rate of the particles decreases, making short-term spheroidization impossible. Further, the reason why the holding time in the above temperature range was limited to 2 minutes or more is because if it is less than 2 minutes, the progress of spheroidization is insufficient. Furthermore, if the cold wire drawing step 12 is not performed, the speed of spheroidization will be slightly slower, so a holding time of 7 minutes or more is desirable. Regarding the upper limit of the holding time, in normal annealing, heating and holding is performed for 10 hours to 100 hours, but in the present invention, effective annealing is performed in a short time as described above, and heating and holding for more than 10 hours is not possible. Thermoeconomically unfavorable. There are two types of heat retention methods; one is to pass through an in-line heat retention furnace 15 for a required period of time before being wound around a coiler 16, as shown in the example shown, and the other is to wind the winding around a coiler. This method involves placing the subsequent raw material coil in a heat retention furnace and holding it for the required time.
In either case, the effect of promoting spheroidization by heat retention is the same. [Example] Next, the effects of the method of the present invention will be explained with reference to Examples. Test Example 1 A hot-rolled wire material made of S45C and a wire diameter of 11.0 mmφ was heated through a high-frequency heating device, then immediately subjected to bending drawing through a roll bending device, and then wound around a coiler in a heat retention furnace. A spheroidization process was performed to retain heat. The conditions for heating, wire drawing, and heat retention in this treatment are as follows. 1 High frequency heating Heating temperature: 300℃ - 900℃ 2 Warm bending wire drawing Roll diameter: 90mmφ, pitch: 130mm Number of rolls: 5 horizontally, 5 vertically Inlet wire temperature: 700℃, outlet wire temperature: 680℃ Applied elongation rate: 5% to 55% 3 Heat retention furnace Furnace temperature: 700℃, coiler diameter: 800mmφ Heat retention time: 2 minutes to 120 minutes after coiler winding Atmosphere gas: N2 gas test example 2 Material is S45C, After heating a hot-rolled wire material with a wire diameter of 11.0 mmφ through a high-frequency heating device, it is immediately subjected to bending drawing through a roll bending device, then passed through a tunnel furnace for heat retention, and then wound onto a coiler outside the furnace. A spheroidization process was performed. The conditions for heating, wire drawing, and heat retention in this treatment are as follows. 1 High frequency heating Heating temperature: 700℃ 2 Warm bending wire drawing Roll diameter: 90mmφ, pitch: 130mm Number of rolls: 5 horizontally, 5 vertically Inlet wire temperature: 700℃, outlet wire temperature: 680℃ Applied elongation rate :55% 3 Heat retention furnace Furnace temperature: 700℃ Passage time: 7 minutes Atmosphere gas: N2 gas Test example 3 A hot-rolled wire material made of SCM435, SCr435 and wire diameter 12.7mmφ was cold rolled and bent. After descaling through a descaling device, the wire was heated with an electric heating device, immediately subjected to warm bending wire drawing through a roll bending device, and then spheroidized by being wound around a coiler in a heat retention furnace to retain heat. . The conditions for heating and wire drawing heat retention in this treatment are as follows. 1 Cold bending wire drawing Applied elongation rate: 25% 2 Electrical heating Heating temperature: 700℃ 3 Warm bending wire drawing Roll diameter: 90mmφ, pitch: 130mm Number of rolls: 5 horizontally, 5 vertically Inlet wire temperature: 700℃, outlet wire temperature: 680℃ Applied elongation rate: 55% 4 Heat retention furnace Furnace temperature: 690℃, coiler diameter: 800mmφ Heat retention time: 15 minutes after coiler winding Atmosphere gas: N2 gas test example 4 Material A hot-rolled wire material of S45C with a wire diameter of 12.7 mmφ is cold descaled through a roll bending device, heated with an electric heating device, immediately subjected to warm bending wire drawing through a roll bending device, and then continued. The material was passed through a tunnel furnace for heat retention, and then wound into a spheroid by winding it around a coiler outside the furnace. The conditions for heating, wire drawing, and heat retention in this treatment are as follows. 1 Cold bending wire drawing, applied elongation rate: 25% 2 Electrical heating Heating temperature: 700℃ 3 Warm bending wire drawing Roll diameter: 90mmφ, pitch: 130mm Number of rolls: 5 horizontally, 5 vertically Inlet wire temperature : 700℃, outlet linear temperature: 680℃ Applied elongation rate: 55% 4 Heat retention furnace Furnace temperature: 690℃ Heat retention time: 7 minutes Atmosphere gas: N2 gas Under each condition according to Test Examples 1 to 4 above , 27 test materials were manufactured by continuously in-line spheroidizing various hot-rolled wire materials. For comparison, a hot-rolled wire material made of S45C with a wire diameter of 90 mmφ was processed through both pickling and lubrication processes to a diameter of 7.37 mm with a die, and then heated to 750℃ for 3.75 hours.
Hold at 750℃ for 3 hours, then 550℃ at 10℃/H.
A conventional example was obtained by performing spheroidizing treatment using the usual method of spheroidizing annealing for 26.65 hours by lowering the temperature to ℃ and then allowing it to cool.
以上説明したように、本発明の鋼棒鋼線の連続
球状化処理方法は、従来方法お酸洗、潤滑等の前
処理工程を省略できて工程が簡略化されるととも
に、長時間を要する焼鈍処理を必要とせず、イン
ラインでの極めて短時間の連続処理を可能とする
ので、冷間鍛造用鋼棒鋼線の球状化処理の生産性
向上、コスト低減等に大きな効果を発揮する。
As explained above, the continuous spheroidization treatment method for steel bars and steel wires of the present invention simplifies the process by omitting the conventional pretreatment steps such as pickling and lubrication, and also simplifies the process, and also simplifies the annealing process, which requires a long time. Since this process does not require continuous in-line processing in an extremely short period of time, it is highly effective in improving productivity and reducing costs in the spheroidizing process of steel bars and wires for cold forging.
第1図は、鋼線の従来の球状化処理方法の一例
を示す説明図。第2図は、本発明方法を実施する
鋼線の球状化処理ラインの一例を示す説明図であ
る。
1:素材コイル、2:酸洗装置、3:潤滑処理
装置、4:ダイス伸線装置、5:球状化焼鈍炉、
6,11:アンゴイラー、7:ダイス、8,1
6:コイラー、10:鋼線素材、12:冷間伸線
工程、13:加熱工程、14:温間伸線工程、1
5:保温処理工程、17:ロール。
FIG. 1 is an explanatory diagram showing an example of a conventional spheroidizing method for steel wire. FIG. 2 is an explanatory diagram showing an example of a steel wire spheroidization treatment line that implements the method of the present invention. 1: Material coil, 2: Pickling device, 3: Lubrication treatment device, 4: Die wire drawing device, 5: Spheroidizing annealing furnace,
6,11: Ungoiler, 7: Dice, 8,1
6: Coiler, 10: Steel wire material, 12: Cold wire drawing process, 13: Heating process, 14: Warm wire drawing process, 1
5: Heat retention treatment step, 17: Roll.
Claims (1)
棒鋼線用素材を、350℃以上850℃以下の温度に加
熱してその温度域でロールベンデイング装置によ
り伸び率5%以上95%以下の伸びを与え、ひきつ
づきコイラーに巻取り前または巻取り後に450℃
以上750℃以下の温度で2分以上10時間以下保持
する処理を連続して実施することを特徴とする鋼
棒鋼線の連続球状化処理方法。 2 炭素量1.5%以下の中・低合金鋼からなる鋼
棒鋼線用素材を予め冷間でロールベンデイング装
置による伸び率5%以上95%以下の伸びを与え、
さらに350℃以上850℃以下の温度に加熱してその
温度域でロールベンデイング装置により伸び率5
%以上95%以下の伸びを与え、ひきつづきコイラ
ーに巻取り前または巻取り後に450℃以上650℃以
下の温度で2分以上10時間以下保持する処理を連
続して実施することを特徴とする鋼棒鋼線の連続
球状化処理方法。[Scope of Claims] 1. A steel bar steel wire material made of medium/low alloy steel with a carbon content of 1.5% or less is heated to a temperature of 350°C or more and 850°C or less, and the elongation rate is determined by a roll bending device in that temperature range. Give an elongation of 5% to 95% and continue to coil the coiler at 450℃ before or after winding.
1. A continuous spheroidizing method for steel bars and wires, characterized by continuously carrying out treatment at a temperature of 750° C. or lower for 2 minutes or more and 10 hours or less. 2. A steel bar and wire material made of medium- and low-alloy steel with a carbon content of 1.5% or less is subjected to cold elongation using a roll bending device at an elongation rate of 5% to 95%,
Furthermore, it is heated to a temperature of 350℃ to 850℃, and in that temperature range, the elongation rate is 5 by roll bending equipment.
% or more and 95% or less, and is continuously subjected to a treatment in which the coiler is held at a temperature of 450°C or more and 650°C or less for 2 minutes or more and 10 hours or less before or after winding. Continuous spheroidization treatment method for steel wire bars.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19196581A JPS5893813A (en) | 1981-11-28 | 1981-11-28 | Continuous spheroidization of steel bar and steel wire |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19196581A JPS5893813A (en) | 1981-11-28 | 1981-11-28 | Continuous spheroidization of steel bar and steel wire |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5893813A JPS5893813A (en) | 1983-06-03 |
JPS6157891B2 true JPS6157891B2 (en) | 1986-12-09 |
Family
ID=16283388
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP19196581A Granted JPS5893813A (en) | 1981-11-28 | 1981-11-28 | Continuous spheroidization of steel bar and steel wire |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5893813A (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20010097137A (en) * | 2000-04-20 | 2001-11-08 | 홍민철 | Method for drawing welding wire |
KR100419496B1 (en) * | 2001-06-19 | 2004-02-19 | 고려용접봉 주식회사 | Method and device for reeling stainless steel flux-cored wire in a spool |
-
1981
- 1981-11-28 JP JP19196581A patent/JPS5893813A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS5893813A (en) | 1983-06-03 |
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