JPH081232A - Cooling method for hot rolled wire rod - Google Patents
Cooling method for hot rolled wire rodInfo
- Publication number
- JPH081232A JPH081232A JP13037494A JP13037494A JPH081232A JP H081232 A JPH081232 A JP H081232A JP 13037494 A JP13037494 A JP 13037494A JP 13037494 A JP13037494 A JP 13037494A JP H081232 A JPH081232 A JP H081232A
- Authority
- JP
- Japan
- Prior art keywords
- hot
- cooling
- wire rod
- rolled wire
- cooling zone
- 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.)
- Withdrawn
Links
Landscapes
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
- Metal Rolling (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、熱間圧延線材の冷却方
法に係り、より詳しくは、圧延速度を低下させることな
く、粉状の赤スケールの発生を効果的に防止することを
可能ならしめるようにした熱間圧延線材の冷却方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling a hot-rolled wire, and more specifically, it is possible to effectively prevent the generation of powdery red scale without lowering the rolling speed. The present invention relates to a method for cooling a hot-rolled wire rod.
【０００２】[0002]
【従来の技術】周知のように、熱間圧延線材の最表層部
には、その冷却過程に起因して、しばしば粉状の赤スケ
ールが発生する。赤スケールは、スケール最表層のヘマ
タイト（Ｆｅ2 Ｏ3 ）がウイスカー状に成長したもので
ある。勿論、このような赤スケールは、線材製品の機械
的強度に悪影響を及ぼすようなことがないので、特に問
題視しない顧客がある反面、製品である線材の表面美観
を損なうばかりでなく、線材の最表層部から離反し、そ
して浮遊粉塵として大気中を漂って作業環境を悪化させ
るので、赤スケールのある線材を不良品と見做す顧客が
ある。そこで、そのような顧客から線材を受注した場合
には、熱間圧延機の圧延速度を遅くすることにより赤ス
ケールの発生を防止していた。2. Description of the Related Art As is well known, powdery red scale is often generated in the outermost layer of a hot rolled wire due to its cooling process. The red scale is a whisker-like growth of hematite (Fe 2 O 3 ) on the outermost layer of the scale. Of course, since such a red scale does not adversely affect the mechanical strength of the wire rod product, there are customers who do not have any particular problems, but on the other hand, it not only spoils the surface aesthetics of the wire rod, which is the product, but also Some customers consider wires with red scale to be defective products because they separate from the outermost layer and drift in the air as suspended dust, deteriorating the work environment. Therefore, when the wire rod is ordered from such a customer, the rolling speed of the hot rolling mill is slowed to prevent the generation of red scale.
【０００３】つまり、赤スケールの発生防止のために圧
延速度を遅くするのは、熱間圧延線材の巻取り温度ある
いは巻取り後のループレイヤーの所定位置での載置温度
を同温にする場合、圧延仕上げ温度を低温にすることが
でき、その分だけ水冷ゾーンにおける熱間圧延線材の温
度低下が少なくなり、冷却過程での熱間圧延線材の断面
内の温度分布が小さくなって赤スケールが発生し難くな
るということを経験的に把握していたためである。しか
しながら、圧延速度を遅くすると、熱間圧延線材の赤ス
ケールの発生を防止し得るものの、線材の生産性を向上
させることができないという解決すべき課題が生じる。
そのため、圧延速度を低下させることなく赤スケールの
防止が可能な熱間圧延線材の冷却方法の実現が望まれて
いた。That is, in order to prevent the generation of red scale, the rolling speed is slowed down when the coiling temperature of the hot-rolled wire or the coiling temperature of the loop layer after coiling is set to the same temperature. , The rolling finishing temperature can be lowered, the temperature decrease of the hot rolled wire rod in the water cooling zone is reduced accordingly, the temperature distribution in the cross section of the hot rolled wire rod in the cooling process becomes small, and the red scale becomes This is because it was empirically understood that it will not occur easily. However, when the rolling speed is slowed down, although the red scale of the hot rolled wire rod can be prevented from being generated, there is a problem to be solved that the productivity of the wire rod cannot be improved.
Therefore, it has been desired to realize a method for cooling a hot rolled wire rod capable of preventing red scale without reducing the rolling speed.
【０００４】ところで、熱間圧延線材の赤スケールの発
生防止に関しては、例えば、特開昭５７−１０６４２３
号公報に示されている。これは、水冷時間ｔW と、大気
中の二次冷却での冷却速度ＶTCを関連付けて、赤スケー
ルの発生防止条件を示したものであり、ｔW ≦｛4.25×
10-3(min／℃）・ＶTC（℃／min)＋0.57｝（ｓ）の式を
満足するように、水冷時間ｔW と冷却速度ＶTCとを決定
してやれば、赤スケールの発生を効果的に防止すること
ができるというものである。より詳しくは、赤スケール
の発生に及ぼす水冷時間ｔW と大気中での冷却速度ＶTC
との関係を、縦軸にＶTC（℃／ｍｉｎ）をとり、横軸に
ｔW （ｓ）をとって示す図８中の一次関数ＶTC＝２３５
ｔW −１３５の左側領域とすれば良いというものであ
る。By the way, regarding the prevention of the red scale of the hot rolled wire rod, for example, JP-A-57-106423 is used.
It is shown in the publication. This shows the condition for preventing the occurrence of red scale by associating the water cooling time t W with the cooling rate V TC in the secondary cooling in the atmosphere, and t W ≤ {4.25 ×
If the water cooling time t W and the cooling rate V TC are determined so that the formula of 10 −3 (min / ° C.) · V TC (° C./min)+0.57}(s) is satisfied, the red scale is generated. Is effectively prevented. More specifically, the water cooling time t W affecting the generation of red scale and the cooling rate V TC in the atmosphere
The linear function V TC = 235 in FIG. 8 in which the vertical axis represents V TC (° C./min) and the horizontal axis represents t W (s).
The area on the left side of t W -135 may be used.
【０００５】[0005]
【発明が解決しようとする課題】上記従来技術に係る冷
却方法は、単に一義的に、水冷時間ｔW と大気中の二次
冷却での冷却速度ＶTCを規定しているだけであって、熱
間圧延線材の寸法および水冷ゾーンの配置等の影響は全
く配慮されていない。また、示されているｔW とＶTCの
関係式ＶTC＝２３５ｔW −１３５も実験的に決定したも
のであるため、この従来技術に係る冷却方法は厳密性に
乏しいという問題がある。The cooling method according to the above-mentioned prior art simply unequivocally defines the water cooling time t W and the cooling rate V TC in the secondary cooling in the atmosphere. No consideration was given to the influence of the dimensions of the hot rolled wire rod and the arrangement of the water cooling zone. Further, since the relational expression V TC = 235 t W -135 between t W and V TC shown is also experimentally determined, there is a problem that the cooling method according to this conventional technique is poor in rigor.
【０００６】従って、本発明の目的とするところは、赤
スケールの発生の有無の判定基準を明らかにすることに
より、圧延速度を低下させることなく、しかも確実に赤
スケールの発生を防止することを可能ならしめる普遍的
な熱間圧延線材の冷却方法を提供するにある。Therefore, an object of the present invention is to prevent the red scale from occurring without lowering the rolling speed by clarifying the criterion for determining the presence or absence of the red scale. It is to provide a universal hot-rolling wire cooling method that enables it.
【０００７】[0007]
【課題を解決するための手段】例えば、Growth of Oxid
e Whiskers on Metals at High Temperature（JOUNALOF
THE PHYSICAL SOCIETY OF JAPAN ，Vol.12,No.11,NOVE
MBER,1957）に記載されているように、結晶同士間のス
リップによってもたらされる転位に関連した酸素の拡散
によりウイスカー状の赤スケールが発生するのである
が、発明者等は鋭意研究を重ねた結果、熱間圧延線材の
赤スケールの発生原因となる結晶同士間のスリップ現象
が、冷却過程における熱間圧延線材の断面内温度分布に
基づく熱応力に起因し、しかも最表層部の熱応力が引張
り応力から、大きく圧縮応力に変わる際の大きな応力変
化に関連しているこを知見して、本発明に係る熱間圧延
線材の冷却方法をなすに至ったものである。[Means for Solving the Problems] For example, Growth of Oxid
e Whiskers on Metals at High Temperature (JOUNALOF
THE PHYSICAL SOCIETY OF JAPAN, Vol.12, No.11, NOVE
As described in MBER, 1957), whiskers-like red scales are generated due to oxygen diffusion related to dislocations caused by slips between crystals. The slip phenomenon between crystals, which causes the red scale of the hot rolled wire rod, is caused by the thermal stress due to the temperature distribution in the cross section of the hot rolled wire rod during the cooling process, and the thermal stress of the outermost layer part is tensile. The present inventors have found that it is related to a large stress change when the stress is largely changed to a compressive stress, and have reached a method of cooling a hot-rolled wire according to the present invention.
【０００８】従って、上記課題を解決するために、本発
明の請求項１に係る熱間圧延線材の冷却方法が採用した
手段の特徴とするところは、熱間圧延機で圧延された熱
間圧延線材をループレイヤー、コンベアを介して巻き取
るに際して、前記熱間圧延機で圧延された熱間圧延線材
を複数の水冷ゾーンからなる前記熱間圧延機とループレ
イヤーとの間に設けられた水冷ラインで冷却する熱間圧
延線材の冷却方法において、前記熱間圧延線材を、前記
水冷ラインの最終水冷ゾーンの上流側水冷ゾーンで強冷
した後、前記最終水冷ゾーンの上流側直前の水冷ゾーン
と最終水冷ゾーンとの間に設けられた復熱ゾーンで、該
最終水冷ゾーンの入側における熱間圧延線材の最表層部
の引張り応力が０以上であってかつ該最終水冷ゾーンの
上流側直前の水冷ゾーンの出側における熱間圧延線材の
最表層部の引張り熱応力の１／２以下になるように復熱
させると共に、復熱させた熱間圧延線材を前記最終水冷
ゾーンで弱冷するところにある。Therefore, in order to solve the above-mentioned problems, the feature of the means adopted by the method for cooling a hot-rolled wire according to claim 1 of the present invention is that the hot-rolling is carried out by a hot-rolling mill. When winding the wire rod through the loop layer and the conveyor, a water-cooling line provided between the hot-rolling machine and the loop layer, which comprises a plurality of water-cooling zones for the hot-rolling wire rolled by the hot-rolling machine. In the method for cooling a hot-rolled wire rod, the hot-rolled wire rod is strongly cooled in the upstream water-cooling zone of the final water-cooling zone of the water-cooling line, and the final water-cooling zone immediately before the upstream side of the final water-cooling zone. In the recuperating zone provided between the water cooling zone and the water cooling zone, the tensile stress of the outermost layer of the hot-rolled wire on the inlet side of the final water cooling zone is 0 or more and immediately before the upstream side of the final water cooling zone. Where the hot-rolled wire rod is reheated so as to be equal to or less than half of the tensile thermal stress of the outermost layer of the hot-rolled wire rod at the outlet side, and the reheated hot-rolled wire rod is weakly cooled in the final water cooling zone. It is in.
【０００９】また、本発明の請求項２に係る熱間圧延線
材の冷却方法が採用した手段の特徴とするところは、請
求項１記載の熱間圧延線材の冷却方法において、前記上
流側水冷ゾーンの単位長さ当たりの冷却能力と、前記最
終水冷ゾーンの単位長さ当たりの冷却能力との冷却能力
比を１〜４対１とするところにある。Further, the feature of the means adopted in the method for cooling a hot-rolled wire according to claim 2 of the present invention is that in the method for cooling a hot-rolled wire according to claim 1, the upstream water cooling zone is provided. The cooling capacity ratio between the cooling capacity per unit length and the cooling capacity per unit length of the final water cooling zone is 1 to 4 to 1.
【００１０】また、本発明の請求項３に係る熱間圧延線
材の冷却方法が採用した手段の特徴とするところは、請
求項１，２記載の熱間圧延線材の冷却方法において、実
機の線材圧延ラインで予め精度を検証した熱間圧延線材
の温度計算モデルを用いて前記線材圧延ラインの水冷過
程での熱間圧延線材の温度・熱応力解析で求めた値か
ら、前記最終水冷ゾーンで弱冷された熱間圧延線材が最
終水冷ゾーンの出側から復熱しながらコンベア上に至
り、断面内の温度が一定になるまでの復熱時間の間の熱
間圧延線材の最表層部の熱応力の変化と定義する熱応力
緩和速度を求め、該熱応力緩和速度が予め設定した値以
下になるように前記熱間圧延線材を復熱させるところに
ある。The means adopted by the method for cooling a hot-rolled wire according to claim 3 of the present invention is characterized in that in the method for cooling a hot-rolled wire according to claims 1 and 2, an actual wire rod is used. Using the temperature calculation model of the hot-rolled wire whose accuracy has been verified in advance on the rolling line, the value obtained by the temperature / thermal stress analysis of the hot-rolled wire in the water-cooling process of the wire-rolling line is weak in the final water-cooling zone. Thermal stress of the outermost layer of the hot-rolled wire rod during the recuperation time until the temperature in the cross section becomes constant while the cooled hot-rolled wire rod reheats from the outlet side of the final water-cooling zone. Is obtained, and the hot-rolled wire rod is reheated so that the thermal stress relaxation rate becomes equal to or lower than a preset value.
【００１１】[0011]
【作用】本発明の請求項１に係る熱間圧延線材の冷却方
法によれば、熱間圧延機から出た高温の熱間圧延線材
は、冷却能力を大きくした水冷ラインの最終水冷ゾーン
の上流側水冷ゾーンで冷却されるが、上流側水冷ゾーン
では熱間圧延線材の最表層部には、断面内温度分布に基
づいて引張り応力が作用するが、急激な応力の緩和がな
いため、熱間圧延線材の温度降下量を比較的大きくする
ことができ、熱間圧延線材を効果的に冷却することがで
きる。一方、上流側水冷ゾーンでの冷却で生じた熱間圧
延線材の断面内温度分布に基づいた引張り応力は、最終
冷却ゾーンの上流側直前の水冷ゾーンと最終水冷ゾーン
との間に設けられた復熱ゾーンで、前記最終冷却ゾーン
の入側における熱間圧延線材の最表層部の引張り熱応力
が０以上であってかつこの最終水冷ゾーンの上流側直前
の水冷ゾーンの出側における熱間圧延線材の最表層部の
引張り熱応力の１／２以下になるように復熱され、次い
で最表層部温度と内部温度との温度差、即ち断面内温度
差に起因する熱応力が小さく保持されながら最終水冷ゾ
ーンで弱冷されるので、最終冷却ゾーンの出側からコン
ベアに至るまでの空冷過程、即ち復熱過程での熱間圧延
線材の最表層部の応力緩和（応力変化）の程度、即ち前
述の応力緩和速度を小さくすることができ、熱間圧延線
材の最表層部の結晶同士間のスリップ現象が抑制される
と考えられ、赤スケールの発生抑制に効果的となる。According to the method for cooling a hot-rolled wire according to the first aspect of the present invention, the hot-rolled wire at a high temperature discharged from the hot-rolling mill is upstream of the final water-cooling zone of the water-cooling line having a large cooling capacity. Although it is cooled in the side water cooling zone, tensile stress acts on the outermost layer of the hot rolled wire rod based on the temperature distribution in the cross section in the upstream water cooling zone, but there is no sudden stress relaxation, so The temperature drop amount of the rolled wire rod can be made relatively large, and the hot rolled wire rod can be effectively cooled. On the other hand, the tensile stress based on the temperature distribution in the cross section of the hot-rolled wire produced by cooling in the upstream water-cooling zone is the recovery stress provided between the water-cooling zone immediately before the upstream side of the final cooling zone and the final water-cooling zone. In the heat zone, the hot rolling wire rod on the inlet side of the final cooling zone has a tensile thermal stress of 0 or more at the outermost layer and is on the outlet side of the water cooling zone immediately upstream of the final water cooling zone. Is reheated to less than 1/2 of the tensile thermal stress of the outermost layer, and then the temperature difference between the outermost layer temperature and the internal temperature, that is, the thermal stress due to the temperature difference in the cross section is kept small and finally Since it is weakly cooled in the water cooling zone, the degree of stress relaxation (stress change) at the outermost layer of the hot-rolled wire rod during the air cooling process from the exit side of the final cooling zone to the conveyor, that is, the recuperation process, Small stress relaxation rate It can be considered that the slip phenomenon between the crystal between the outermost layer of the hot rolled wire rod can be suppressed, the effective red scale formation suppressing.
【００１２】また、本発明の請求項２に係る熱間圧延線
材の冷却方法によれば、最終水冷ゾーンの冷却能力を１
としたとき、熱間圧延機から出た高温の熱間圧延線材が
水冷ラインの最終水冷ゾーンの上流側水冷ゾーンで１〜
４倍の冷却能力で冷却されるが、上記のように、上流側
水冷ゾーンでは熱間圧延線材の最表層部には、断面内温
度分布に基づいて引張り応力が作用するが、急激な応力
緩和がないため、熱間圧延線材の温度降下量を比較的大
きくすることができ、熱間圧延線材を効果的に冷却する
ことができる。一方、上流側水冷ゾーンで生じた熱間圧
延線材の断面内温度分布に基づいた引張り応力は、最終
水冷ゾーンの上流側直前の水冷ゾーンと最終水冷ゾーン
との間に設けられた復熱ゾーンで、前記最終水冷ゾーン
の入側における熱間圧延線材の最表層部の引張り熱応力
が０以上であってかつこの最終水冷ゾーンの上流側直前
の水冷ゾーンの出側における熱間圧延線材の最表層部の
引張り熱応力の１／２以下になるように復熱され、次い
で最表層部温度と内部温度との温度差、即ち断面内温度
差に起因する熱応力が小さく保持されながら最終水冷ゾ
ーンで弱冷されるので、最終冷却ゾーンの出側からコン
ベアに至るまでの空冷過程、即ち復熱過程での熱間圧延
線材の最表層部の応力緩和速度を小さくすることがで
き、熱間圧延線材の最表層部の結晶同士間のスリップ現
象が抑制されると考えられ、赤スケールの発生抑制に効
果的となる。Further, according to the method for cooling a hot-rolled wire according to claim 2 of the present invention, the cooling capacity of the final water cooling zone is 1
Then, the high-temperature hot-rolled wire rod that has come out of the hot-rolling mill is 1 to 1 in the upstream water-cooling zone of the final water-cooling zone of the water-cooling line.
Although it is cooled with four times the cooling capacity, as described above, tensile stress acts on the outermost surface layer of the hot-rolled wire rod based on the temperature distribution in the cross section in the upstream water cooling zone, but sudden stress relaxation Therefore, the temperature drop amount of the hot rolled wire rod can be made relatively large, and the hot rolled wire rod can be effectively cooled. On the other hand, the tensile stress based on the temperature distribution in the cross section of the hot-rolled wire produced in the upstream water-cooling zone is in the recuperation zone provided between the water-cooling zone immediately upstream of the final water-cooling zone and the final water-cooling zone. An outermost layer of the hot-rolled wire at the exit side of the water-cooling zone immediately before the upstream side of the final water-cooling zone and having a tensile thermal stress of 0 or more at the entrance side of the final water-cooling zone Is reheated to less than 1/2 of the tensile thermal stress of the part, and then the temperature difference between the outermost layer temperature and the internal temperature, that is, the thermal stress due to the temperature difference in the cross section is kept small while the final water cooling zone is maintained. Since it is weakly cooled, it is possible to reduce the stress relaxation rate of the outermost layer of the hot-rolled wire rod in the air-cooling process from the exit side of the final cooling zone to the conveyor, that is, the reheat process, and the hot-rolled wire rod Crystal of the outermost layer of Believed slip phenomenon between Judges are suppressed and effective red scale formation suppressing.
【００１３】また、本発明の請求項３に係る熱間圧延線
材の冷却方法によれば、熱間圧延線材の径に応じて、応
力緩和速度を予め定めて前記最終水冷ゾーンの出側から
コンベアに至るまでの空冷過程、即ち復熱過程において
その応力緩和速度以下になるように、上記のとおり、上
流側水冷ゾーン、復熱ゾーン、最終水冷ゾーンでの冷却
を調整することにより、熱間圧延線材の最表層部の熱応
力変化を小さくすることができるので、最表層部におけ
る結晶同士間のスリップ現象を抑制することができると
考えられ、赤スケールの発生抑制に効果的となる。そし
て、演算で求められる熱応力緩和速度を活用するので普
遍性も高い。Further, according to the method for cooling a hot-rolled wire according to the third aspect of the present invention, the stress relaxation rate is set in advance according to the diameter of the hot-rolled wire, and the conveyor is provided from the exit side of the final water cooling zone. By adjusting the cooling in the upstream side water cooling zone, the recuperation zone, and the final water cooling zone, as described above, so that the stress relaxation rate is less than or equal to that in the air cooling process up to Since the change in thermal stress in the outermost layer of the wire can be reduced, it is considered that the slip phenomenon between the crystals in the outermost layer can be suppressed, which is effective in suppressing the generation of red scale. Moreover, since the thermal stress relaxation rate required by calculation is utilized, it is highly universal.
【００１４】[0014]
【実施例】以下、本発明の実施例に係る熱間圧延線材の
冷却方法を実施するのに用いた水冷ラインを含む線材圧
延ラインの仕上部を示す模式的構成説明図の図１と、熱
応力緩和速度と復熱速度との関係説明図の図２と、冷却
能力の配分比と熱応力緩和速度との関係説明図の図３
と、復熱時間と熱間圧延線材の径との関係説明図の図４
と、本発明の冷却方法による熱間圧延線材の水冷過程に
おける温度の推移説明図の図５（ａ）と、水冷に伴う熱
間圧延線材の熱応力の推移説明図の図５（ｂ）と、従来
の冷却方法による熱間圧延線材（比較例１）の水冷過程
における温度の推移説明図の図６（ａ）と、水冷に伴う
熱間圧延線材の熱応力の推移説明図の図６（ｂ）と、従
来の冷却方法による熱間圧延線材（比較例２）の水冷過
程における温度の推移説明図の図７（ａ）と、水冷に伴
う熱間圧延線材の熱応力の推移説明図の図７（ｂ）とを
参照しながら説明する。EXAMPLES Hereinafter, FIG. 1 is a schematic configuration explanatory view showing the finish of a wire rod rolling line including a water cooling line used for carrying out a method for cooling a hot rolled wire rod according to an example of the present invention, and FIG. FIG. 2 is an explanatory diagram of the relationship between the stress relaxation rate and the heat recovery rate, and FIG. 3 is an explanatory diagram of the relationship between the distribution ratio of the cooling capacity and the thermal stress relaxation rate.
And FIG. 4 of the explanatory view of the relationship between the recuperation time and the diameter of the hot rolled wire rod.
FIG. 5 (a) of the temperature transition explanatory diagram in the water cooling process of the hot rolled wire rod by the cooling method of the present invention, and FIG. 5 (b) of the thermal stress transition explanatory diagram of the hot rolled wire rod due to the water cooling. FIG. 6 (a) of a temperature transition explanatory diagram of a hot-rolled wire rod (Comparative Example 1) by a conventional cooling method in a water cooling process and FIG. 6 (a) of a thermal stress transition explanatory diagram of a hot-rolled wire rod due to water cooling ( b), and FIG. 7A of the temperature transition explanatory diagram in the water cooling process of the hot-rolled wire rod (Comparative Example 2) by the conventional cooling method, and FIG. 7A and the transition explanatory diagram of the thermal stress of the hot-rolled wire rod due to water cooling. Description will be given with reference to FIG.
【００１５】先ず、本発明に係る熱間圧延線材の冷却方
法を実施するのに用いた水冷ラインを含む線材圧延ライ
ンの仕上部を、図１を参照しながら説明すると、同図に
示す符号１は、仕上げ熱間圧延機（以下、ミルとい
う。）であり、このミル１で圧延された熱間圧延線材Ｗ
の搬送先側には、ミル１側から順に第１水冷ゾーン２
ａ、第２水冷ゾーン２ｂ、第３水冷ゾーン２ｃ、復熱ゾ
ーン２ｄ、最終水冷ゾーンである第４水冷ゾーン２ｅと
からなる水冷ライン２が配置され、次いでループレイヤ
ー３、このループレイヤー３で螺旋状に巻かれた熱間圧
延線材Ｗを搬送するコンベア４が配置されてなる構成に
なっている。First, the finish of a wire rod rolling line including a water cooling line used for carrying out the method for cooling a hot rolled wire rod according to the present invention will be described with reference to FIG. Is a finishing hot rolling mill (hereinafter referred to as a mill), and is a hot-rolled wire rod W rolled by the mill 1.
The first water cooling zone 2 in order from the mill 1 side to the destination side of
a, a second water-cooling zone 2b, a third water-cooling zone 2c, a recuperating zone 2d, and a fourth water-cooling zone 2e, which is the final water-cooling zone, are arranged, and then a loop layer 3 and a spiral in this loop layer 3 are arranged. The conveyor 4 for transporting the hot-rolled wire W wound in a strip shape is arranged.
【００１６】つまり、ミル１で圧延された高温の熱間圧
延線材Ｗは、第１水冷ゾーン２ａ、第２水冷ゾーン２
ｂ、第３水冷ゾーン２ｃに順次通されて冷却され、次い
で復熱ゾーン２ｄで復熱された後に第４水冷ゾーン２ｅ
で冷却されると共に、この第４水冷ゾーン２ｅを出てル
ープレイヤー３で螺旋状に巻かれてコンベア４に載置、
搬送される過程で、空冷あるいは風冷され、予め設定し
た範囲内の温度に冷却される。That is, the high-temperature hot-rolled wire W rolled by the mill 1 has the first water cooling zone 2a and the second water cooling zone 2
b, the third water cooling zone 2c is successively passed through to be cooled, and then the heat is regenerated in the recuperating zone 2d, and then the fourth water cooling zone 2e.
While being cooled by, it exits the fourth water cooling zone 2e, is spirally wound by the loop layer 3, and is placed on the conveyor 4,
In the process of being transported, it is air-cooled or air-cooled and cooled to a temperature within a preset range.
【００１７】発明者等は、上記構成になる線材圧延ライ
ンによる線材の圧延テスト中に、熱間圧延線材Ｗの冷却
過程において、その断面内に生じる温度分布に基づく熱
応力分布に起因して熱間圧延線材Ｗに赤スケールが発生
し、特に、断面内の熱応力分布が大きいほど赤スケール
が発生し易いという事実を突き止めた。より具体的に
は、赤スケールは、第４水冷ゾーンによる水冷後の復熱
過程における熱間圧延線材Ｗの最表層部の後述する定義
になる熱応力緩和速度が大きいほど発生し易いというこ
とを確認した。The inventors of the present invention, during the rolling test of the wire rod by the wire rod rolling line having the above-mentioned structure, generate heat due to the thermal stress distribution based on the temperature distribution generated in the cross section in the cooling process of the hot rolled wire rod W. It has been found that red scale is generated in the hot-rolled wire W, and in particular, the larger the thermal stress distribution in the cross section is, the more easily red scale is generated. More specifically, the red scale is more likely to be generated as the thermal stress relaxation rate, which will be defined later, of the outermost surface layer portion of the hot-rolled wire W in the recuperation process after water cooling by the fourth water cooling zone is larger. confirmed.
【００１８】そして、発明者等は、鋭意研究を重ねた結
果、このような赤スケールの発生を防止するためには、
熱間圧延線材Ｗの断面内の熱応力分布（温度分布）に基
づいた判定パラメータを設定し、この判定パラメータの
値をある基準以下にすることが極めて有効であるという
結論を導き出した。また、このような判定パラメータと
しては、前記熱応力緩和速度あるいは後述する定義にな
る復熱速度が有効であることも突き止めた。As a result of intensive studies, the inventors have found that in order to prevent the occurrence of such a red scale,
It was concluded that it is extremely effective to set a judgment parameter based on the thermal stress distribution (temperature distribution) in the cross section of the hot-rolled wire W and set the value of this judgment parameter to a certain standard or less. Further, it was also found that the thermal stress relaxation rate or the recuperation rate defined below is effective as such a determination parameter.
【００１９】なお、前記判定パラメータのうち、熱応力
緩和速度（ｋｇｆ／ｍｍ2 ／ｓ）は、前記第４水冷ゾー
ン２ｅで弱冷された熱間圧延線材Ｗが、この第４水冷ゾ
ーン２ｅの出側から復熱しながらコンベア４上に至り、
断面内の温度が一定になるまでの復熱時間（ｓ）の間の
熱間圧延線材Ｗの最表層部の熱応力の変化と定義される
ものである。また、復熱速度（℃／ｓ）は、第４水冷ゾ
ーン２ｅの出側から復熱しながらコンベア４上に至り、
断面内の温度が一定になるまでの熱間圧延線材Ｗの最表
層部の復熱温度（℃）を、前記復熱時間（ｓ）で除した
値と定義されるものである。Among the above-mentioned judgment parameters, the thermal stress relaxation rate (kgf / mm 2 / s) shows that the hot-rolled wire W weakly cooled in the fourth water-cooling zone 2e is in the fourth water-cooling zone 2e. While recuperating from the outlet side, it reaches the conveyor 4,
It is defined as a change in the thermal stress in the outermost layer portion of the hot-rolled wire W during the recuperation time (s) until the temperature in the cross section becomes constant. Further, the recuperation rate (° C / s) reaches the conveyor 4 while recuperating from the outlet side of the fourth water cooling zone 2e,
It is defined as a value obtained by dividing the recuperation temperature (° C.) of the outermost surface layer portion of the hot rolled wire W until the temperature in the cross section becomes constant by the recuperation time (s).
【００２０】さらに、前記熱応力緩和速度と復熱速度と
の関係は、直径９ｍｍの炭素鋼線材について、縦軸に熱
応力緩和速度（ｋｇｆ／ｍｍ2 ／ｓ）をとり、横軸に復
熱速度（℃／ｓ）をとって示す図２のように、一義的に
対応しており、しかも、熱応力緩和速度を約２５ｋｇｆ
／ｍｍ2 以下とすれば、熱間圧延線材Ｗの赤スケールの
発生を確実に防止し得ることが判った。勿論、熱応力緩
和速度は主に熱間圧延線材Ｗの径によって相違するの
で、予め実機の線材圧延ラインにおいて精度を検証した
熱間圧延線材の温度計算モデルを用いて、水冷過程での
温度・熱応力解析を行って熱応力緩和速度を求め、求め
られる熱応力緩和速度が予め設定した値以下になるよう
に、冷却過程における熱間圧延線材の冷却条件を設定す
れば良い。つまり、これにより、本発明に係る熱間圧延
線材の冷却方法の普遍性が確保されるものである。Further, regarding the relationship between the thermal stress relaxation rate and the recuperative rate, regarding the carbon steel wire having a diameter of 9 mm, the ordinate represents the thermal stress relaxation rate (kgf / mm 2 / s) and the abscissa represents the recuperative rate. As shown in FIG. 2 which shows the velocity (° C./s), there is a unique correspondence, and the thermal stress relaxation rate is about 25 kgf.
It has been found that the red scale of the hot-rolled wire W can be reliably prevented by setting it to be less than / mm 2 . Of course, the thermal stress relaxation rate mainly differs depending on the diameter of the hot-rolled wire W. Therefore, using the temperature calculation model of the hot-rolled wire whose accuracy was verified in advance in the actual wire-rolling line, the temperature in the water-cooling process The thermal stress relaxation rate may be obtained by performing thermal stress analysis, and the cooling conditions for the hot rolled wire rod in the cooling process may be set so that the obtained thermal stress relaxation rate is equal to or less than a preset value. In other words, this ensures the universality of the method for cooling the hot-rolled wire according to the present invention.
【００２１】ところで、従来の線材圧延ラインの水冷ラ
イン２では、複数ある水冷ゾーンそれぞれの冷却域単位
長さ当たりの冷却水量は等しく設定されていることが多
い。このような冷却方法であると、熱間圧延線材Ｗが水
冷ライン２の各水冷ゾーンを通過するにつれてその断面
内の熱応力分布（温度分布）は大きくなり、最終水冷ゾ
ーンである第４水冷ゾーン２ｅの後工程の空冷、風冷に
よる復熱領域においても前記判定パラメータ、つまり熱
応力緩和速度、復熱速度が比較的大きく、製品である線
材に赤スケールが発生する場合が多い。By the way, in the conventional water cooling line 2 of the wire rod rolling line, the amount of cooling water per unit length of the cooling zone in each of the plurality of water cooling zones is often set to be equal. With such a cooling method, as the hot-rolled wire W passes through each water-cooling zone of the water-cooling line 2, the thermal stress distribution (temperature distribution) in its cross section becomes large, and the fourth water-cooling zone which is the final water-cooling zone. Even in the heat recovery region by air cooling or air cooling in the post-process of 2e, the determination parameters, that is, the thermal stress relaxation rate and the heat recovery rate are relatively large, and red scale often occurs in the wire rod as a product.
【００２２】そこで、図１に示す冷却ライン２で詳細に
検証した温度計算モデルを用いて、圧延速度をそれほど
低下させることなく前記判定パラメータの値を小さくし
得る冷却方法を検討した結果、水冷ライン２の第１水冷
ゾーン２ａ、第２水冷ゾーン２ｂ、第３水冷ゾーン２ｃ
（以下、前段水冷ゾーンという。）と、第４水冷ゾーン
２ｅとの冷却能力の適切な配分および復熱ゾーン２ｄの
長さの適切な選定が有効であることが判った。つまり、
熱応力緩和速度や復熱速度という概念の採用による熱間
圧延線材Ｗの赤スケールの発生防止には、前記復熱ゾー
ン２ｄにおいて、ある温度だけは必ず復熱させる場合に
限り有効になる。以下、これら前段水冷ゾーンと第４水
冷ゾーン２ｅとの冷却能力の配分比および復熱ゾーン２
ｄの長さの限定条件を説明する。Therefore, as a result of studying a cooling method capable of reducing the value of the judgment parameter without significantly lowering the rolling speed by using the temperature calculation model which has been verified in detail in the cooling line 2 shown in FIG. 2nd 1st water cooling zone 2a, 2nd water cooling zone 2b, 3rd water cooling zone 2c
It has been found that appropriate distribution of the cooling capacity between the water cooling zone (hereinafter referred to as the former water cooling zone) and the fourth water cooling zone 2e and an appropriate selection of the length of the recuperation zone 2d are effective. That is,
In order to prevent the red scale from occurring in the hot-rolled wire W by adopting the concepts of the thermal stress relaxation rate and the recuperation rate, only a certain temperature in the recuperation zone 2d is effective only when the heat is recuperated. Hereinafter, the distribution ratio of the cooling capacities of the preceding stage water cooling zone and the fourth water cooling zone 2e and the recuperation zone 2 will be described.
The limiting condition for the length of d will be described.
【００２３】先ず、冷却能力の配分比の限定条件につい
ては、図１に基づいて説明した水冷ライン２で、線材寸
法φ９ｍｍの炭素鋼線材（仕上げ圧延速度６０ｍ／ｓ）
を冷却する場合を考える。この場合、前段水冷ゾーン２
ａ、２ｂ、２ｃおよび第４水冷ゾーン２ｅの冷却能力の
配分比を１．０〜７．０まで変化させて、前段水冷ゾー
ン２ａ、２ｂ、２ｃおよび第４水冷ゾーン２ｅによる水
冷後の熱間圧延線材Ｗの最表層部の熱応力緩和速度を求
めた。その結果は、縦軸に熱応力緩和速度をとり、横軸
に冷却能力配分比をとって示す図３のとおりである。こ
こで、何れの配分比の場合も、熱間圧延線材Ｗの巻取り
後のコンベア上の所定の位置での温度は８７３〜８７６
℃である。First, regarding the limiting condition of the distribution ratio of the cooling capacity, in the water cooling line 2 described with reference to FIG. 1, a carbon steel wire rod having a wire rod size of φ9 mm (finish rolling speed 60 m / s).
Consider the case of cooling. In this case, the former water cooling zone 2
a, 2b, 2c and the cooling capacity distribution ratio of the fourth water cooling zone 2e are changed from 1.0 to 7.0, and the hot water after water cooling by the preceding water cooling zones 2a, 2b, 2c and the fourth water cooling zone 2e is performed. The thermal stress relaxation rate of the outermost layer portion of the rolled wire W was obtained. The results are shown in FIG. 3, where the vertical axis represents the thermal stress relaxation rate and the horizontal axis represents the cooling capacity distribution ratio. Here, in any of the distribution ratios, the temperature at a predetermined position on the conveyor after winding the hot-rolled wire W is 873 to 876.
° C.
【００２４】図３によれば、前記冷却能力の配分比が大
きくなればなるほど熱間圧延線材Ｗの最表層部の熱応力
緩和速度が小さくなることが判る。つまり、このことは
前段水冷ゾーン２ａ、２ｂ、２ｃの冷却能力を大きくし
て行くことにより、熱間圧延線材Ｗの巻取り後の所定の
位置での温度を同温とした場合に、最終水冷ゾーンであ
る第４水冷ゾーン２ｅでの冷却能力を小さくでき、最終
水冷ゾーン２ｅの出側での断面内温度差（温度分布）に
基づく熱応力分布を小さくすることができる。その結
果、最終水冷ゾーン２ｅの出側からコンベアに至るまで
の空冷領域における空冷過程、即ち復熱過程での熱間圧
延線材Ｗの最表層部の応力緩和速度を小さくでき、製品
である線材に赤スケールが発生し難くなることを示唆す
るものである。なお、これらの冷却能力は水冷ゾーンの
単位長さ当たりの冷却水量に対応するもので、冷却能力
の配分比１．０では前段水冷ゾーン２ａ、２ｂ、２ｃと
第４水冷ゾーン２ｅとの実冷却能力の比はおよそ３対１
となり、また冷却能力の配分比７．０の場合の実冷却能
力の比はおよそ２１対１となるものである。It can be seen from FIG. 3 that the thermal stress relaxation rate of the outermost surface layer of the hot rolled wire W decreases as the distribution ratio of the cooling capacity increases. That is, this means that by increasing the cooling capacity of the front-stage water cooling zones 2a, 2b, 2c, when the temperature at a predetermined position after winding the hot-rolled wire W is the same, the final water-cooling is performed. The cooling capacity in the fourth water cooling zone 2e, which is a zone, can be reduced, and the thermal stress distribution based on the cross-sectional temperature difference (temperature distribution) on the exit side of the final water cooling zone 2e can be reduced. As a result, the stress relaxation rate of the outermost surface layer of the hot-rolled wire W in the air-cooling process in the air-cooling region from the exit side of the final water-cooling zone 2e to the conveyor, that is, in the reheat process, can be reduced, and the product wire rod can be obtained. This suggests that the red scale is less likely to occur. Note that these cooling capacities correspond to the amount of cooling water per unit length of the water cooling zone, and when the cooling capacity distribution ratio is 1.0, the actual cooling of the preceding water cooling zones 2a, 2b, 2c and the fourth water cooling zone 2e is performed. Ability ratio is about 3 to 1
Further, when the distribution ratio of the cooling capacity is 7.0, the ratio of the actual cooling capacity is about 21: 1.
【００２５】上記のとおり、前段水冷ゾーン２ａ、２
ｂ、２ｃの冷却能力を大きくすればするほど、熱応力緩
和速度は小さくなり、赤スケールの発生防止に効果的で
あることが示されている。しかしながら、前段水冷ゾー
ン２ａ、２ｂ、２ｃの冷却能力を大きくし過ぎると、最
終水冷ゾーンである第４水冷ゾーン２ｅの冷却能力が小
さくなり過ぎ、即ち冷却水量が少なくなり過ぎ、水冷管
内の冷却水の流れが不均一になり、また制御が困難にな
って均一に水冷することができなくなる。As described above, the pre-stage water cooling zones 2a, 2
It has been shown that the larger the cooling capacities of b and 2c, the smaller the thermal stress relaxation rate, and the more effective the prevention of red scale is. However, if the cooling capacity of the preceding water cooling zones 2a, 2b, 2c is made too large, the cooling capacity of the fourth water cooling zone 2e, which is the final water cooling zone, becomes too small, that is, the amount of cooling water becomes too small, and the cooling water in the water cooling pipe becomes too small. Flow becomes non-uniform, and it becomes difficult to control it, so that uniform water cooling cannot be performed.
【００２６】さらに、最終水冷ゾーンである第４水冷ゾ
ーン２ｅでの水冷の程度が少ないから、熱間圧延線材Ｗ
は、結果的に復熱ゾーン２ｄの直前の第３水冷ゾーン２
ｃの出側から復熱した場合と類似の冷却来歴を辿ること
になる。つまり、前段水冷ゾーン２ａ，２ｂ，２ｃでの
水冷の程度が大きく、従って水冷ゾーン２ｃの出側の熱
間圧延線材Ｗの断面内温度分布、即ち熱応力分布が大き
な状態から復熱した場合と同様の来歴をとるため、水冷
ゾーン２ｃ以後の熱応力緩和速度が実質的に大きくなる
ので、製品である線材に対する赤スケールの発生防止に
対して寄与することができなくなる。Furthermore, since the degree of water cooling in the fourth water cooling zone 2e, which is the final water cooling zone, is small, the hot rolled wire W
Is, as a result, the third water cooling zone 2 immediately before the recuperation zone 2d.
A cooling history similar to that when the heat is recovered from the outlet side of c is followed. That is, the degree of water cooling in the pre-stage water cooling zones 2a, 2b, 2c is large, and therefore the temperature distribution in the cross section of the hot-rolled wire W on the exit side of the water cooling zone 2c, that is, the case where the heat stress distribution is large is recovered. Since the same history is taken, the thermal stress relaxation rate after the water cooling zone 2c becomes substantially large, and it becomes impossible to contribute to the prevention of the generation of red scale on the wire rod which is a product.
【００２７】勿論、図１に示す水冷ライン２による実操
業範囲では、前段水冷ゾーン２ａ、２ｂ、２ｃと第４水
冷ゾーン２ｅとの冷却能力の比を１〜４対１程度にして
おくことが望ましい。このように、冷却能力の比を４対
１にすれば、第４水冷ゾーン２ｅの冷却能力は、通常の
操業範囲においては約８．３８×１０6 Ｊ／ｍ2 ｈ℃
（２０００ｋｃａｌ／ｍ2 ｈ℃）程度となり、冷却管内
の冷却水の流れの不均一や制御性の問題は解消される。Of course, in the actual operating range of the water cooling line 2 shown in FIG. 1, the cooling capacity ratio of the front water cooling zones 2a, 2b, 2c and the fourth water cooling zone 2e may be set to about 1 to 4: 1. desirable. Thus, if the cooling capacity ratio is set to 4: 1, the cooling capacity of the fourth water cooling zone 2e will be about 8.38 × 10 6 J / m 2 h ° C. in the normal operating range.
(2000 kcal / m 2 h ° C.), the problems of non-uniformity of the flow of cooling water in the cooling pipe and controllability are solved.
【００２８】次に、前段水冷ゾーン２ａ、２ｂ、２ｃと
第４水冷ゾーン２ｅとの間に設けられている復熱ゾーン
２ｄの長さについて規定する。赤スケールの発生を防止
するには、上記のとおり、この復熱ゾーン２ｄで復熱さ
せて熱間圧延線材Ｗの断面内温度分布を小さくしておく
必要がある。これにより、第４水冷ゾーン２ｅ通過後の
空冷または風冷による復熱領域における熱応力緩和速度
が小さくなり、赤スケールの発生を抑制することが可能
になる。Next, the length of the recuperating zone 2d provided between the pre-stage water cooling zones 2a, 2b, 2c and the fourth water cooling zone 2e will be specified. In order to prevent the generation of red scale, as described above, it is necessary to reheat in the recuperation zone 2d to reduce the temperature distribution in the cross section of the hot rolled wire W. As a result, the thermal stress relaxation rate in the recuperation region due to air cooling or air cooling after passing through the fourth water cooling zone 2e becomes small, and it becomes possible to suppress the generation of red scale.
【００２９】即ち、復熱ゾーン２ｄの長さがあまり短か
過ぎると、復熱が不十分であるために熱間圧延線材Ｗの
断面内温度分布が小さくならず、第４水冷ゾーン２ｅ通
過後の応力緩和速度もあまり小さくならないので、上記
理由により、赤スケールの発生防止に対して効果がな
い。逆に、前記復熱ゾーン２ｄの長さが非常に長けれ
ば、この復熱ゾーン２ｄで熱応力の緩和が終了してしま
い、熱間圧延線材Ｗの最表層部の応力が前段水冷ゾーン
２ａ、２ｂ、２ｃによる水冷終了後の引張り応力から圧
縮応力に急激に変化するので、赤スケールが極めて発生
し易い状態になってしまう。That is, if the length of the recuperation zone 2d is too short, the recuperation is insufficient and the temperature distribution in the cross section of the hot-rolled wire W does not become small, so that after passing through the fourth water cooling zone 2e. Since the stress relaxation rate of 1 does not become so small, it is not effective for preventing the generation of red scale for the above reason. On the contrary, if the length of the recuperation zone 2d is very long, the relaxation of the thermal stress ends in this recuperation zone 2d, and the stress of the outermost layer portion of the hot-rolled wire W becomes the pre-water cooling zone 2a, Since the tensile stress after completion of water cooling due to 2b and 2c suddenly changes to the compressive stress, a red scale is extremely likely to occur.
【００３０】上記のような事実から勘案すると、復熱ゾ
ーン２ｄの長さは、前段水冷ゾーン２ａ、２ｂ、２ｃの
出側における熱間圧延線材Ｗの最表層部の熱応力値を１
／２程度に減少させることのできる長さ以上であって、
かつ熱間圧延線材Ｗの最表層部の引張り応力が圧縮応力
に変化しない程度、つまり熱間圧延線材Ｗの最表層部の
熱応力が０となる程度に止め得る長さ以下にすることが
望ましい。In consideration of the above facts, the length of the recuperating zone 2d is 1 when the thermal stress value of the outermost layer of the hot-rolled wire W on the exit side of the pre-water cooling zones 2a, 2b, 2c is 1.
It is longer than the length that can be reduced to about 1/2,
In addition, it is desirable that the tensile stress of the outermost layer portion of the hot rolled wire W does not change to a compressive stress, that is, the length is such that it can be stopped so that the thermal stress of the outermost layer portion of the hot rolled wire W becomes zero. .
【００３１】直径の異なる熱間圧延線材Ｗのそれぞれ
を、図１に示した水冷ライン２で冷却する場合、復熱ゾ
ーン２ｄにおける復熱過程において、熱間圧延線材Ｗの
最表層部の熱応力が第３水冷ゾーン２ｃの出側における
応力の１／２になるまでの時間（白丸で示している。）
および０になるまでの時間（白丸で示している。）を、
前述の温度・熱応力計算モデルを用いて算出した結果
は、縦軸に時間（ｓ）をとり、横軸に熱間圧延線材とし
て炭素鋼線材の径（ｍｍ）をとって示す図４のとおりで
ある。When the hot-rolled wire rods W having different diameters are cooled by the water-cooling line 2 shown in FIG. 1, in the recuperation process in the recuperation zone 2d, the thermal stress of the outermost layer of the hot-rolled wire rod W is increased. Until it becomes 1/2 of the stress on the exit side of the third water cooling zone 2c (indicated by white circles).
And the time until it becomes 0 (indicated by a white circle),
The results calculated using the above temperature / thermal stress calculation model are shown in FIG. 4 in which the vertical axis represents time (s) and the horizontal axis represents the diameter (mm) of the carbon steel wire rod as the hot-rolled wire rod. Is.
【００３２】つまり、復熱ゾーン２ｄの長さとしては、
図４に示す斜線の復熱時間がとれるような長さが望まし
く、この水冷ライン２における通常の操業条件では、復
熱ゾーン２ｄの長さは、およそ０．３〜７．５ｍの範囲
となる。なお、各直径の熱間圧延線材それぞれの巻取り
後の所定位置での線材表面温度は何れも約８７５℃であ
り、圧延速度はそれぞれφ６．４ｍｍの場合が８０ｍ／
ｓ、φ９ｍｍの場合が６０ｍ／ｓ、φ１２ｍｍの場合が
３８ｍ／ｓである。That is, as the length of the recuperation zone 2d,
It is desirable that the hatched length shown in FIG. 4 be such that the recuperation time can be taken, and under normal operating conditions in this water cooling line 2, the length of the recuperation zone 2d will be in the range of approximately 0.3 to 7.5 m. . In addition, the wire surface temperature at each predetermined position after winding of each hot-rolled wire of each diameter is about 875 ° C., and the rolling speed is 80 m / mm in the case of φ6.4 mm.
In the case of s and φ9 mm, it is 60 m / s, and in the case of φ12 mm, it is 38 m / s.
【００３３】一般に、熱間圧延線材の仕上げ圧延速度は
各工場によって異なるものであり、それに応じて図４に
示した復熱時間の範囲も幾分異なるものである。具体的
には、圧延速度がより高速になれば、前段水冷ゾーン２
ａ、２ｂ、２ｃの出側から熱間圧延線材の最表層部の熱
応力が１／２に減少するのに必要な復熱ゾーン２ｄの長
さは長くなる傾向がある。従って、復熱ゾーン２ｄの長
さは約０．５ｍは必要である。同様に、復熱ゾーン２ｄ
の最大長さは、必ずしも７．５ｍに限定されるものでは
ない。しかし、あまりに長すぎると、水冷ライン２のレ
イアウト全体が大規模なものとなり、通常１０ｍ程度に
止めておくことが望ましい。In general, the finishing rolling speed of the hot rolled wire rod differs depending on each factory, and accordingly, the range of the recuperation time shown in FIG. 4 also differs somewhat. Specifically, if the rolling speed becomes higher, the former water cooling zone 2
The length of the recuperation zone 2d necessary for reducing the thermal stress of the outermost layer portion of the hot rolled wire rod from the outlet sides of a, 2b and 2c to 1/2 tends to be long. Therefore, the reheat zone 2d needs to have a length of about 0.5 m. Similarly, recuperation zone 2d
The maximum length of is not necessarily limited to 7.5 m. However, if it is too long, the entire layout of the water cooling line 2 becomes large, and it is usually desirable to keep it to about 10 m.
【００３４】以下、図１に基づいて説明した水冷ライン
２により実施した、本発明の熱間圧延線材の冷却方法に
係る実施例を説明する。但し、復熱ゾーン２ｄの長さ
は、第４水冷ゾーン２ｅの長さの５４％とした。線径が
φ９ｍｍの熱間圧延線材（それぞれ５本づつ）について
行った本発明の実施例と、前段水冷ゾーン２ａ，２ｂ，
２ｃと第４水冷ゾーン２ｅとの冷却能力を等しくした比
較例１，２とについて、熱間圧延線材Ｗの冷却条件の差
に基づく赤スケール発生の有無を調べた。An embodiment of the method for cooling a hot-rolled wire according to the present invention, which is carried out by the water cooling line 2 described with reference to FIG. 1, will be described below. However, the length of the recuperation zone 2d was set to 54% of the length of the fourth water cooling zone 2e. Examples of the present invention performed on hot-rolled wire rods each having a wire diameter of 9 mm (5 each), and pre-water cooling zones 2a, 2b,
For Comparative Examples 1 and 2 in which the cooling capacities of 2c and the fourth water-cooling zone 2e were equal, the presence or absence of red scale was examined based on the difference in the cooling conditions of the hot-rolled wire W.
【００３５】なお、本発明の実施例における熱間圧延線
材の温度の推移（縦軸は温度℃、横軸は冷却開始からの
距離ｍ）と熱応力の推移（縦軸は熱応力ｋｇｆ／ｍ
ｍ2 、横軸は冷却開始からの距離ｍ）は図５（ａ），５
（ｂ）に示すとおりであり、比較例１における熱間圧延
線材の温度の推移と熱応力の推移は図６（ａ），６
（ｂ）に示すとおりであり、さらに比較例２における熱
間圧延線材の温度の推移と熱応力の推移は図７（ａ），
７（ｂ）に示すとおりである。In the examples of the present invention, changes in temperature of the hot-rolled wire (vertical axis is temperature ° C, horizontal axis is distance m from the start of cooling) and changes in thermal stress (vertical axis is thermal stress kgf / m).
m 2 and the horizontal axis is the distance m from the start of cooling.
As shown in FIG. 6B, the transition of the temperature and the transition of the thermal stress of the hot rolled wire rod in Comparative Example 1 are shown in FIGS.
As shown in FIG. 7B, the temperature transition and the thermal stress transition of the hot-rolled wire rod in Comparative Example 2 are shown in FIG.
This is as shown in 7 (b).
【００３６】図５（ａ），５（ｂ）に示す本実施例は圧
延速度が６０ｍ／ｓ、冷却能力の配分比が２．５３対１
であって、熱間圧延線材に赤スケールが発生しておら
ず、図６（ａ），６（ｂ）に示す比較例１は圧延速度が
５０ｍ／ｓ、冷却能力の配分比が１対１で、圧延速度が
遅いことに起因して赤スケールが発生しておらず、そし
て図７（ａ），７（ｂ）に示す比較例２は圧延速度が６
０ｍ／ｓ、冷却能力の配分比が１対１で、赤スケールが
発生している。これら各図の比較において、本発明の実
施例になる熱間圧延線材の温度推移と熱応力の推移は、
比較例１と比較例２とのほぼ中間状態にあり、圧延速度
が比較例２の場合と同等であるにもかかわらず、冷却能
力比の配分の相違により赤スケールの発生が防止されて
いる。In this embodiment shown in FIGS. 5 (a) and 5 (b), the rolling speed is 60 m / s and the cooling capacity distribution ratio is 2.53: 1.
In the comparative example 1 shown in FIGS. 6A and 6B, the rolling speed was 50 m / s and the cooling capacity distribution ratio was 1: 1. In the comparative example 2 shown in FIGS. 7 (a) and 7 (b), the red scale did not occur due to the slow rolling speed, and the rolling speed was 6%.
0m / s, the distribution ratio of the cooling capacity is 1: 1 and the red scale is generated. In the comparison of these respective figures, the temperature transition and the thermal stress transition of the hot-rolled wire according to the example of the present invention are:
Although the comparative example 1 and the comparative example 2 are almost in the intermediate state and the rolling speed is the same as that of the comparative example 2, the generation of the red scale is prevented due to the difference in the distribution of the cooling capacity ratios.
【００３７】以下、以上の比較を、熱応力緩和速度、復
熱速度などを含めて取纏めたものを表１に示す。Table 1 shows a summary of the above comparison including the thermal stress relaxation rate and the recuperation rate.
【表１】 [Table 1]
【００３８】表１において、本実施例と各水冷ゾーンに
均等に冷却能力を配分した比較例２とを比べた場合、圧
延速度および巻取り温度が同じでも、第４水冷ゾーン２
ｅの冷却能力を、前段水冷ゾーン２ａ，２ｂ，２ｃの冷
却能力よりも小さくし、さらに熱応力緩和速度、復熱速
度を比較例１に近い値にすることにより、製品である線
材への赤スケールの発生が防止されていることが判る。
一方、各水冷ゾーンに均等に冷却能力を配分した比較例
１では、熱応力緩和速度、復熱速度を小さくするために
圧延速度を５０ｍ／ｓにしなければ、赤スケールの発生
を抑制することができない。このように、本発明に係る
熱間圧延線材の冷却方法によれば、圧延速度を１０ｍ／
ｓ程度速くしても線材製品に赤スケールが発生せず、線
材製品の生産性の低下を防止することができる。In Table 1, when this example is compared with Comparative Example 2 in which the cooling capacity is evenly distributed to each water cooling zone, even if the rolling speed and the winding temperature are the same, the fourth water cooling zone 2
By making the cooling capacity of e smaller than the cooling capacity of the preceding water cooling zones 2a, 2b, 2c, and further setting the thermal stress relaxation rate and the recuperation rate to values close to those of Comparative Example 1, red to the product wire rod can be obtained. It can be seen that generation of scale is prevented.
On the other hand, in Comparative Example 1 in which the cooling capacity is evenly distributed to each water cooling zone, the generation of red scale can be suppressed unless the rolling speed is set to 50 m / s in order to reduce the thermal stress relaxation rate and the recuperation rate. Can not. Thus, according to the method for cooling a hot-rolled wire according to the present invention, the rolling speed is 10 m /
Even if the speed is increased by about s, red scale does not occur in the wire product, and the productivity of the wire product can be prevented from lowering.
【００３９】ところで、以上では、限られた冷却能力の
配分比と熱応力緩和速度との場合を例として説明した
が、直径の異なる熱間圧延線材に対する種々のテストの
結果、冷却能力の配分比は１〜４対１の範囲、つまり前
段水冷ゾーン２ａ、２ｂ、２ｃと第４水冷ゾーン２ｅと
の間の復熱領域２ｄにおける復熱が、前記第４水冷ゾー
ン２ｅの入側における熱間圧延線材Ｗの最表層部の引張
り応力が０以上であってかつこの第４水冷ゾーン２ｅの
上流側直前の第３水冷ゾーン２ｃの出側における熱間圧
延線材Ｗの最表層部の引張り熱応力の１／２以下であれ
ば、線材に全く赤スケールが発生しないことを確認し
た。また、以上では、前段水冷ゾーン２ａ、２ｂ、２ｃ
と第４水冷ゾーン２ｅからなる４つの水冷ゾーンを水冷
ライン２を用いた場合の例を説明したが、予め実機の水
冷ラインで精度を検証した温度モデルを用いて種々の径
の熱間圧延線材に対する熱応力緩和速度と復熱速度とを
設定しておけば、構成の相違する水冷ゾーンを有する他
の線材圧延ラインに対する適用も可能である。なお、上
記熱応力値は、実機の線材圧延ラインで予め精度を検証
した熱間圧延線材の温度計算モデルを用いての線材圧延
ラインの水冷過程での温度解析結果に基づいた熱間圧延
線材の最表層部にスケールが成長していくとみなした場
合（即ち、最表層部はスケール層）の弾性解析によるも
のである。In the above, the case where the distribution ratio of the cooling capacity and the thermal stress relaxation rate are limited has been described as an example. However, as a result of various tests on hot-rolled wire rods having different diameters, the distribution ratio of the cooling capacity is shown. Is in the range of 1 to 4 to 1, that is, the recuperation in the recuperation area 2d between the preceding water cooling zones 2a, 2b, 2c and the fourth water cooling zone 2e is the hot rolling on the inlet side of the fourth water cooling zone 2e. Of the tensile stress of the outermost surface portion of the hot-rolled wire W at the exit side of the third water cooling zone 2c immediately before the upstream side of the fourth water cooling zone 2e when the tensile stress of the outermost surface portion of the wire material W is 0 or more. It was confirmed that when the ratio was 1/2 or less, no red scale was generated on the wire. Further, in the above, the pre-stage water cooling zones 2a, 2b, 2c are provided.
An example of the case where the water cooling line 2 is used as the four water cooling zones including the fourth water cooling zone 2e and the fourth water cooling zone 2e has been described. However, hot rolling wire rods of various diameters are used by using a temperature model whose accuracy has been verified in advance with an actual water cooling line. By setting the thermal stress relaxation rate and the recuperation rate with respect to, it is possible to apply to other wire rod rolling lines having water cooling zones of different configurations. Incidentally, the thermal stress value, the hot rolling wire rod based on the temperature analysis result in the water cooling process of the wire rod rolling line using the temperature calculation model of the hot rolling wire rod whose accuracy was verified in advance in the actual wire rod rolling line. This is based on elasticity analysis when it is considered that the scale grows on the outermost layer (that is, the outermost layer is the scale layer).
【００４０】[0040]
【発明の効果】以上詳述したように、本発明に係る熱間
圧延線材の冷却方法によれば、熱間圧延機から出た高温
の熱間圧延線材を、上流側水冷ゾーンでは熱間圧延線材
の最表層部には、断面内温度分布に基づいて引張り応力
が作用するが、急激な応力緩和がないため、熱間圧延線
材の温度降下量を比較的大きくすることができ、熱間圧
延線材を効果的に冷却することができる。一方、上流側
水冷ゾーンでの冷却で生じた熱間圧延線材の断面内温度
分布に基づいた引張り応力は、最終冷却ゾーンの上流側
直前の水冷ゾーンと最終水冷ゾーンとの間に設けられた
復熱ゾーンで、前記最終冷却ゾーンの入側における熱間
圧延線材の最表層部の引張り熱応力が０以上であってか
つ最終冷却ゾーンの上流側直前の水冷ゾーンの出側にお
ける熱間圧延線材の最表層部の引張り熱応力の１／２以
下になるように復熱され、次いで最表層部温度と内部温
度との温度差、即ち断面内温度差に起因する熱応力を小
さく保持しながら最終水冷ゾーンで弱冷されるので、最
終冷却ゾーンの出側からコンベアに至るまでの空冷過
程、即ち復熱過程での熱間圧延線材の最表層部の応力緩
和速度を小さくすることができ、赤スケール発生防止
と、生産性の向上とに対して多大な効果がある。さら
に、実際の線材圧延ラインで予め精度を検証した熱間圧
延線材の温度計算モデルを用いて前記線材圧延ラインの
水冷過程での熱間圧延線材の温度・熱応力解析で求めた
熱応力緩和速度を活用するので、他の線材圧延ラインや
線径の相違する熱間圧延線材に対しても容易に適用で
き、その普遍性が優れているという効果もある。As described in detail above, according to the method for cooling a hot-rolled wire according to the present invention, the hot-rolled wire at a high temperature discharged from the hot-rolling mill is hot-rolled in the upstream water cooling zone. Tensile stress acts on the outermost layer of the wire rod based on the temperature distribution in the cross section, but since there is no sudden stress relaxation, the temperature drop of the hot rolled wire rod can be made relatively large, and hot rolling can be performed. The wire can be cooled effectively. On the other hand, the tensile stress based on the temperature distribution in the cross section of the hot-rolled wire produced by cooling in the upstream water-cooling zone is the recovery stress provided between the water-cooling zone immediately before the upstream side of the final cooling zone and the final water-cooling zone. In the heat zone, the tensile heat stress of the outermost layer of the hot rolled wire rod on the inlet side of the final cooling zone is 0 or more and the hot rolled wire rod on the outlet side of the water cooling zone immediately before the upstream side of the final cooling zone. It is reheated to less than half of the tensile thermal stress of the outermost layer and then final water cooling while keeping the thermal stress due to the temperature difference between the outermost layer temperature and the internal temperature, that is, the temperature difference in the cross section, small. Since it is weakly cooled in the zone, it is possible to reduce the stress relaxation rate of the outermost layer of the hot-rolled wire rod in the air cooling process from the exit side of the final cooling zone to the conveyor, that is, in the reheat process, and the red scale Prevention and production There is a great effect on the improvement of. Furthermore, the thermal stress relaxation rate obtained by temperature / thermal stress analysis of the hot rolled wire rod in the water cooling process of the wire rod rolling line using the temperature calculation model of the hot rolled wire rod whose accuracy was verified in advance on the actual wire rod rolling line. Since it is utilized, it can be easily applied to other wire rod rolling lines and hot-rolled wire rods having different wire diameters, and has an effect that its universality is excellent.
【図１】本発明の実施例に係る熱間圧延線材の冷却方法
を実施するのに用いた水冷ラインを含む線材圧延ライン
の仕上部を示す模式的構成説明図である。FIG. 1 is a schematic configuration explanatory view showing a finish of a wire rod rolling line including a water cooling line used for carrying out a method for cooling a hot rolled wire rod according to an embodiment of the present invention.
【図２】本発明の実施例に係る熱間圧延線材の冷却方法
の熱応力緩和速度と復熱速度との関係説明図である。FIG. 2 is an explanatory diagram of a relationship between a thermal stress relaxation rate and a recuperation rate in a method for cooling a hot-rolled wire according to an example of the present invention.
【図３】本発明の実施例に係る熱間圧延線材の冷却方法
の冷却能力の配分比と熱応力緩和速度との関係説明図で
ある。FIG. 3 is a diagram for explaining the relationship between the distribution ratio of the cooling capacity and the thermal stress relaxation rate in the method for cooling a hot rolled wire rod according to the example of the present invention.
【図４】本発明の実施例に係る熱間圧延線材の冷却方法
の復熱時間と熱間圧延線材の径との関係説明図である。FIG. 4 is an explanatory view of the relationship between the recuperation time and the diameter of the hot rolled wire rod in the method for cooling the hot rolled wire rod according to the example of the present invention.
【図５】図５（ａ）は本発明の実施例に係る熱間圧延線
材の冷却方法による熱間圧延線材の水冷過程における温
度の推移説明図であり、図５（ｂ）は水冷に伴う熱間圧
延線材の熱応力の推移説明図である。FIG. 5 (a) is a temperature transition explanatory diagram in the water cooling process of the hot rolled wire rod according to the method for cooling a hot rolled wire rod according to the embodiment of the present invention, and FIG. 5 (b) is associated with water cooling. It is a transition explanatory view of the heat stress of a hot rolled wire rod.
【図６】図６（ａ）は従来の冷却方法による熱間圧延線
材（比較例１）の水冷過程における温度の推移説明図で
あり、図６（ｂ）は水冷に伴う熱間圧延線材の熱応力の
推移説明図である。FIG. 6 (a) is an explanatory view of temperature transition in a water cooling process of a hot rolled wire rod (Comparative Example 1) by a conventional cooling method, and FIG. 6 (b) shows a hot rolled wire rod accompanying water cooling. It is a transition explanatory view of thermal stress.
【図７】図７（ａ）は従来の冷却方法による熱間圧延線
材（比較例２）の水冷過程における温度の推移説明図で
あり、図７（ｂ）は水冷に伴う熱間圧延線材の熱応力の
推移説明図である。FIG. 7 (a) is an explanatory diagram of temperature transition in a water cooling process of a hot rolled wire rod (Comparative Example 2) by a conventional cooling method, and FIG. 7 (b) is a hot rolled wire rod accompanying water cooling. It is a transition explanatory view of thermal stress.
【図８】従来例に係り、赤スケールの発生に及ぼす水冷
時間ｔW と大気中での冷却速度ＶTCとの関係説明図であ
る。FIG. 8 is a diagram for explaining the relationship between the water cooling time t W and the cooling rate V TC in the atmosphere, which affects the generation of red scale, according to the conventional example.
１…ミル（熱間圧延機） ２…水冷ライン，２ａ…第１水冷ゾーン，２ｂ…第２水
冷ゾーン，２ｃ…第３水冷ゾーン，２ｄ…復熱ゾーン，
２ｅ…第４水冷ゾーン ３…ループレイヤー ４…コンベア Ｗ…熱間圧延線材1 ... Mill (hot rolling mill) 2 ... Water cooling line, 2a ... 1st water cooling zone, 2b ... 2nd water cooling zone, 2c ... 3rd water cooling zone, 2d ... Recuperation zone,
2e ... 4th water cooling zone 3 ... Loop layer 4 ... Conveyor W ... Hot rolled wire rod
Claims (3)
ループレイヤー、コンベアを介して巻き取るに際して、
前記熱間圧延機で圧延された熱間圧延線材を複数の水冷
ゾーンからなる前記熱間圧延機とループレイヤーとの間
に設けられた水冷ラインで冷却する熱間圧延線材の冷却
方法において、前記熱間圧延線材を、前記水冷ラインの
最終水冷ゾーンの上流側水冷ゾーンで強冷した後、前記
最終水冷ゾーンの上流側直前の水冷ゾーンと最終水冷ゾ
ーンとの間に設けられた復熱ゾーンで、該最終水冷ゾー
ンの入側における熱間圧延線材の最表層部の引張り応力
が０以上であってかつ該最終水冷ゾーンの上流側直前の
水冷ゾーンの出側における熱間圧延線材の最表層部の引
張り熱応力の１／２以下になるように復熱させると共
に、復熱させた熱間圧延線材を前記最終水冷ゾーンで弱
冷することを特徴とする熱間圧延線材の冷却方法。1. When winding a hot rolled wire rod rolled by a hot rolling mill through a loop layer and a conveyor,
In the cooling method of the hot-rolled wire rod, wherein the hot-rolled wire rod rolled by the hot-rolling mill is cooled by a water-cooling line provided between the hot-rolling device and the loop layer, which comprises a plurality of water-cooling zones, The hot-rolled wire rod, after being strongly cooled in the upstream water cooling zone of the final water cooling zone of the water cooling line, in a recuperation zone provided between the water cooling zone immediately before the upstream side of the final water cooling zone and the final water cooling zone. An outermost layer portion of the hot-rolled wire rod on the outlet side of the water-cooling zone immediately before the upstream side of the final water-cooling zone and having a tensile stress of 0 or more on the inlet side of the final water-cooling zone The method for cooling a hot-rolled wire rod is characterized in that the hot-rolled wire rod is reheated so that the tensile heat stress becomes 1/2 or less and the hot-rolled wire rod that has been reheated is weakly cooled in the final water cooling zone.
の冷却能力と、前記最終水冷ゾーンの単位長さ当たりの
冷却能力との冷却能力比を１〜４対１とすることを特徴
とする請求項１記載の熱間圧延線材の冷却方法。2. The cooling capacity ratio between the cooling capacity per unit length of the upstream side water cooling zone and the cooling capacity per unit length of the final water cooling zone is 1 to 4: 1. The method for cooling a hot-rolled wire according to claim 1.
した熱間圧延線材の温度計算モデルを用いて前記線材圧
延ラインの水冷過程での熱間圧延線材の温度・熱応力解
析で求めた値から、前記最終水冷ゾーンで弱冷された熱
間圧延線材が最終水冷ゾーンの出側から復熱しながらコ
ンベア上に至り、断面内の温度が一定になるまでの復熱
時間の間の熱間圧延線材の最表層部の熱応力の変化と定
義する熱応力緩和速度を求め、該熱応力緩和速度が予め
設定した値以下になるように前記熱間圧延線材を復熱さ
せることを特徴とする請求項１，２記載の熱間圧延線材
の冷却方法。3. A value obtained by temperature / thermal stress analysis of a hot rolled wire rod in a water cooling process of the wire rod rolling line using a temperature calculation model of the hot rolled wire rod whose accuracy has been verified in advance on an actual wire rod rolling line. From the above, the hot-rolled wire that has been weakly cooled in the final water-cooling zone reaches the conveyor while recovering heat from the exit side of the final water-cooling zone, and hot-rolling during the reheat time until the temperature in the cross section becomes constant. A thermal stress relaxation rate, which is defined as a change in the thermal stress of the outermost layer of the wire, is obtained, and the hot-rolled wire is reheated so that the thermal stress relaxation rate is equal to or less than a preset value. Item 3. A method for cooling a hot-rolled wire according to items 1 and 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13037494A JPH081232A (en) | 1994-06-13 | 1994-06-13 | Cooling method for hot rolled wire rod |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13037494A JPH081232A (en) | 1994-06-13 | 1994-06-13 | Cooling method for hot rolled wire rod |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH081232A true JPH081232A (en) | 1996-01-09 |
Family
ID=15032836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13037494A Withdrawn JPH081232A (en) | 1994-06-13 | 1994-06-13 | Cooling method for hot rolled wire rod |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH081232A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7080836B2 (en) | 2003-06-12 | 2006-07-25 | Nisca Corporation | Sheet feeding apparatus and image reading apparatus equipped with the same |
| CN100435990C (en) * | 2004-11-17 | 2008-11-26 | 首钢总公司 | After-roll reinforced cooling process for 82B wire rod steel strand |
| JP2009241134A (en) * | 2008-03-31 | 2009-10-22 | Kobe Steel Ltd | Line for rolling and manufacturing steel wire rod and method of manufacturing steel wire rod |
| JP2009241133A (en) * | 2008-03-31 | 2009-10-22 | Kobe Steel Ltd | Method of manufacturing bar steel and wire rod |
-
1994
- 1994-06-13 JP JP13037494A patent/JPH081232A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7080836B2 (en) | 2003-06-12 | 2006-07-25 | Nisca Corporation | Sheet feeding apparatus and image reading apparatus equipped with the same |
| CN100435990C (en) * | 2004-11-17 | 2008-11-26 | 首钢总公司 | After-roll reinforced cooling process for 82B wire rod steel strand |
| JP2009241134A (en) * | 2008-03-31 | 2009-10-22 | Kobe Steel Ltd | Line for rolling and manufacturing steel wire rod and method of manufacturing steel wire rod |
| JP2009241133A (en) * | 2008-03-31 | 2009-10-22 | Kobe Steel Ltd | Method of manufacturing bar steel and wire rod |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2004137597A (en) | Hot rolled wire rod in which heat treatment before wire drawing can be eliminated, and having excellent wire drawability | |
| US5606787A (en) | Continuous method for producing final gauge stainless steel product | |
| CN108495723B (en) | Hot-rolled steel strip manufacturing equipment row and hot-rolled steel strip manufacturing method | |
| JPH081232A (en) | Cooling method for hot rolled wire rod | |
| JP5213497B2 (en) | Manufacturing method of strip steel wire | |
| JP4016894B2 (en) | Steel wire rod and method for manufacturing steel wire | |
| US3783043A (en) | Treatment of hot-rolled steel rod | |
| US3574000A (en) | High flexibility steel wire and method of treating same | |
| US3320101A (en) | Hot rolled steel rod | |
| KR101442891B1 (en) | Apparatus and method for roughing mill | |
| KR101018178B1 (en) | Wire Rod Manufacturing Method | |
| CN116237367A (en) | Steel coil preparation method for preventing 700MPa thin and wide gauge hot-rolled strip steel flat coil | |
| JP6447836B2 (en) | Hot-rolled steel strip manufacturing method and hot-rolled steel strip manufacturing equipment | |
| JP2002126814A (en) | Hot rolling method | |
| JP2006159261A (en) | Manufacturing method and manufacturing apparatus for hot-rolled steel sheet | |
| JP2002361314A (en) | Continuous heat treatment equipment and continuous heat treatment method for hot rolled sheet of grain-oriented silicon steel | |
| JP2004332107A (en) | Method of heat treatment for steel wire | |
| JP2009241134A (en) | Line for rolling and manufacturing steel wire rod and method of manufacturing steel wire rod | |
| JP2003305502A (en) | Hot rolled steel sheet manufacturing method and hot rolling device | |
| JPS5997705A (en) | Continuous rolling method | |
| KR960006029B1 (en) | Making method of high-carbon steel wire rod | |
| JP2004099984A (en) | Hot rolled steel strip manufacturing method and manufacturing equipment | |
| JP4927320B2 (en) | Manufacturing method of bright annealed austenitic stainless steel strip | |
| JPH1094811A (en) | Determination of Rolling Order of Steel Sheet in Hot Rolling Continuous Process | |
| JP2008212965A (en) | Hot rolling method and hot rolling equipment for steel bars and wires |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20010904 |