JP2981097B2 - How to join billets - Google Patents

How to join billets

Info

Publication number
JP2981097B2
JP2981097B2 JP5316750A JP31675093A JP2981097B2 JP 2981097 B2 JP2981097 B2 JP 2981097B2 JP 5316750 A JP5316750 A JP 5316750A JP 31675093 A JP31675093 A JP 31675093A JP 2981097 B2 JP2981097 B2 JP 2981097B2
Authority
JP
Japan
Prior art keywords
slab
billet
coil
width direction
slabs
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP5316750A
Other languages
Japanese (ja)
Other versions
JPH07164017A (en
Inventor
望 田村
敏明 天笠
英幸 二階堂
博右 山田
茂 磯山
毅 平林
和夫 森本
学夫 橋本
秀夫 坂本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Mitsubishi Electric Corp
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Electric Corp
Mitsubishi Heavy Industries Ltd
Kawasaki Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp, Mitsubishi Heavy Industries Ltd, Kawasaki Steel Corp filed Critical Mitsubishi Electric Corp
Priority to JP5316750A priority Critical patent/JP2981097B2/en
Publication of JPH07164017A publication Critical patent/JPH07164017A/en
Application granted granted Critical
Publication of JP2981097B2 publication Critical patent/JP2981097B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Landscapes

  • General Induction Heating (AREA)
  • Metal Rolling (AREA)
  • Pressure Welding/Diffusion-Bonding (AREA)

Description

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

【0001】[0001]

【産業上の利用分野】この発明は、特に圧延ラインにお
ける鋼片の接合方法に関する。この方法は、例えば熱間
圧延の仕上圧延の入り側搬送ラインにおいて、先行して
搬送する鋼片(以下、先行鋼片という)の後端部と、こ
れに引き続いて搬送する鋼片(以下、後行鋼片という)
の先端部とを、接合してから仕上圧延に供することによ
り、鋼片を連続的に熱間圧延するのに有用である。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining billets in a rolling line. In this method, for example, in the entrance-side transfer line of the finish rolling of hot rolling, a rear end portion of a slab to be transported in advance (hereinafter, referred to as a preceding slab) and a slab to be subsequently transported (hereinafter, referred to as a slab). The following billet)
By subjecting the tip portion to finish rolling after joining, it is useful for continuously hot rolling the billet.

【0002】[0002]

【従来の技術】圧延ラインにおいて、先行鋼片の後端部
と後行鋼片の先端部とを誘導電流による抵抗加熱によっ
て該鋼片のそれぞれを加熱しつつ接合する方法として
は、特開昭62−234679号公報に開示された技術
がある。この技術は、2枚の鋼片の突き合わせ面を小ギ
ャップを空けてほぼ平行に対向させ、板材の上下面を挟
むように対向配設した一対の誘導加熱コイルに中周波ま
たは高周波電力を供給して鋼片を垂直に貫通する交番磁
界により鋼片に誘導電流を生じさせて鋼片を加熱しつつ
突き合わせ面同志を押圧するようにしたものである。
2. Description of the Related Art In a rolling line, a method of joining a rear end portion of a preceding steel slab and a front end portion of a succeeding slab while heating each of the slabs by resistance heating by an induced current is disclosed in Japanese Unexamined Patent Publication (Kokai). There is a technique disclosed in JP-A-62-234679. According to this technology, two steel slabs are opposed to each other almost in parallel with a small gap therebetween, and a medium-frequency or high-frequency power is supplied to a pair of induction heating coils that are arranged opposite to sandwich the upper and lower surfaces of the plate. In this method, an induced current is generated in the steel slab by an alternating magnetic field vertically penetrating the steel slab, and the slabs are pressed against each other while heating the steel slab.

【0003】[0003]

【発明が解決しようとする課題】上記特開昭62−23
4679号公報に開示された方法を実際の鋼片接合に適
用した場合は、場合によっては鋼片の接合面が幅方向に
わたって均一に加熱されず、良好な接合が得られないこ
とがあった。具体的には、鋼片の幅方向端部の昇温程度
が幅方向中央部に比べ著しく劣る結果、幅方向端部の接
合が不十分となっていた。これを回避するために突き合
わせ面相互の押圧力を高めることも考えられるが、この
ような押圧力を高める方法では、押圧手段であるクラン
プ等のいたずらな設備過大化を招くという問題があっ
た。
SUMMARY OF THE INVENTION The above Japanese Patent Application Laid-Open No. 62-23 / 1987
When the method disclosed in Japanese Patent No. 4679 is applied to actual billet joining, the joint surface of the billet may not be uniformly heated in the width direction, and good joining may not be obtained in some cases. Specifically, the degree of temperature rise at the width direction end of the steel slab was remarkably inferior to that at the center in the width direction, resulting in insufficient bonding at the width direction end. In order to avoid this, it is conceivable to increase the pressing force between the butting surfaces. However, such a method of increasing the pressing force has a problem that unnecessarily large equipment such as a clamp serving as a pressing means is caused.

【0004】この発明は、上記の問題を有利に解決する
もので、鋼片幅方向にわたる均一加熱を安定して行うこ
とを可能にする鋼片の接合方法を提案することを目的と
する。
An object of the present invention is to advantageously solve the above-mentioned problem, and an object of the present invention is to propose a method of joining steel slabs which enables stable heating in the width direction of the slab.

【0005】[0005]

【課題を解決するための手段】発明者らは、前述した鋼
片幅方向において昇温速度が異なる原因について研究を
進めたところ、鋼片幅方向端部の昇温不良は、鋼片と誘
導加熱コイルとの位置関係が要因の一つであることを見
いだした。すなわち、鋼片を挟むように配置した一対の
誘導加熱コイルの位置を、鋼片幅方向に種々に動かして
鋼片幅方向にわたって昇温速度を調べたところ、鋼片幅
方向端部の昇温速度が幅方向に比べて著しく劣る状況が
生じること、また、昇温速度が劣る領域は、幅方向端部
に限られること、さらに、この鋼片幅方向端部の昇温状
況は、誘導加熱コイルの磁極間に鋼片幅方向端部が位置
しているか否かで大きく傾向が分かれることも見いだし
た。
Means for Solving the Problems The inventors of the present invention have conducted research on the cause of the above-mentioned difference in the rate of temperature rise in the billet width direction. We found that the positional relationship with the heating coil was one of the factors. That is, when the positions of a pair of induction heating coils arranged so as to sandwich the slab were variously moved in the slab width direction and the heating rate was examined over the slab width direction, the temperature increase at the end of the slab width direction was observed. The situation where the speed is extremely inferior to the width direction occurs, and the region where the heating rate is inferior is limited to the end in the width direction. It has also been found that the tendency largely depends on whether or not the end in the width direction of the slab is located between the magnetic poles of the coil.

【0006】そこから、鋼片と誘導加熱コイルとの位置
関係を最適状態にしたこの発明の要旨構成は、次のとお
りである。 圧延機入側の圧延ラインにて、先行してラインを搬送
させる鋼片の後端部と、この鋼片に追随して搬送させる
鋼片の先端部とを対向させ、この対向させた鋼片の後端
部及び先端部を挟んで磁極を対向させた1対以上の誘導
加熱コイルを配置して、このコイルの磁極から該鋼片の
厚み方向に貫通する交番磁界を印加することより鋼片に
生ずる誘導電流により該鋼片を加熱する工程と、該鋼片
を相互に押圧する工程との組み合わせにより鋼片を接合
する方法において、上記誘導加熱コイルの磁極を鋼片幅
方向端部よりも外方にはみ出させ、鋼片から磁極が幅方
向にはみ出す長さB(m) を誘導電流の浸透深さδとの関
係で次式
The gist of the present invention, in which the positional relationship between the steel slab and the induction heating coil is optimized, is as follows. In the rolling line on the entry side of the rolling mill, the rear end of the slab to be conveyed ahead of the line and the front end of the slab to be conveyed following the slab are opposed to each other. One or more pairs of induction heating coils whose magnetic poles are opposed to each other with the rear end and the front end thereof interposed therebetween are arranged, and an alternating magnetic field penetrating in the thickness direction of the steel slab from the magnetic poles of the coil is applied. Heating the steel slab by the induced current generated in the method, and joining the steel slabs by a step of pressing the steel slabs together. The length B (m) of the magnetic pole protruding outward from the steel slab in the width direction is expressed by the following formula in relation to the penetration depth δ of the induced current.

【数2】 を満足させることを特徴とする鋼片の接合方法。(Equation 2) A method for joining billets, characterized by satisfying the following.

【0007】圧延機入側の圧延ラインにて、先行して
ラインを搬送させる鋼片の後端部と、この鋼片に追随し
て搬送させる鋼片の先端部とを対向させ、この対向させ
た鋼片の後端部及び先端部を挟んで磁極を対向させた1
対以上の誘導加熱コイルを配置して、このコイルの磁極
から該鋼片の厚み方向に貫通する交番磁界を印加するこ
とより鋼片に生ずる誘導電流により該鋼片を加熱する工
程と、該鋼片を相互に押圧する工程との組み合わせによ
り鋼片を接合する方法において、上記誘導加熱コイルの
磁極を鋼片幅方向端部よりも外方にはみ出させ、鋼片か
ら磁極が幅方向にはみ出す長さB(m) を鋼片と磁極との
間隔D(m) との関係でD≦1.5 ×Bを満足させることを
特徴とする鋼片の接合方法。
[0007] In the rolling line on the entry side of the rolling mill, the rear end of the billet to be conveyed ahead of the line and the leading end of the billet to be conveyed following this bill are opposed to each other. The magnetic poles are opposed to each other across the rear and front ends of
A step of arranging at least one pair of induction heating coils and heating the slab by an induction current generated in the slab by applying an alternating magnetic field penetrating in the thickness direction of the slab from the magnetic pole of the coil; A method for joining steel slabs in combination with a step of mutually pressing the slabs, wherein the magnetic poles of the induction heating coil protrude outward from the ends of the slabs in the width direction, and the magnetic poles protrude from the slabs in the width direction. A method of joining steel slabs, wherein the relation B (m) is satisfied in relation to the distance D (m) between the steel slab and the magnetic pole by D ≦ 1.5 × B.

【0008】[0008]

【作用】図1〜図3は、この発明を説明するために先行
鋼片と後行鋼片との接合領域を示す図面である。図1
は、誘導加熱コイルとしてC型コイルと称されるものを
用いた例であり、このC型コイル1は、通電コイル2が
概略C型になる鉄心3のギャップ近傍に巻回されてな
り、この通電コイルを交流電源4に接続することにより
鉄心3の間隙の対向面が一対の磁極となり、この間隙に
磁束が形成される。そして、この間隙に鋼片5.6を通
すことにより該鋼片の厚み方向に磁束が貫通する。
FIGS. 1 to 3 are views showing a joining area between a preceding billet and a succeeding billet for explaining the present invention. FIG.
Is an example in which what is called a C-shaped coil is used as an induction heating coil. The C-shaped coil 1 is wound around a gap of an iron core 3 in which an energizing coil 2 is substantially C-shaped. By connecting the energizing coil to the AC power supply 4, the opposing surfaces of the gap of the iron core 3 become a pair of magnetic poles, and a magnetic flux is formed in the gap. The magnetic flux penetrates in the thickness direction of the slab by passing the slab 5.6 through the gap.

【0009】また、図2は、広幅の鋼片7,8を接合す
る場合に、図1に示したC型の誘導加熱コイル1を鋼片
幅方向に2対配置した例である。さらに、図3は、C型
ではない誘導加熱コイルを用いた例であり、鋼片9,10
の接合端部を上下に挟むように該コイル11,12を配置
し、このコイル11,12に交流電源4を接続したものであ
る。
FIG. 2 shows an example in which two pairs of the C-shaped induction heating coils 1 shown in FIG. 1 are arranged in the width direction of the steel slab when the wide steel slabs 7 and 8 are joined. FIG. 3 shows an example in which an induction heating coil other than the C type is used.
The coils 11 and 12 are arranged so as to vertically sandwich the joining end of the coil, and an AC power supply 4 is connected to the coils 11 and 12.

【0010】図1〜図3に示した誘導加熱コイルの磁極
間に発生する誘導磁束は、大別すると鋼片を鋼片厚み方
向に貫くもの(I) 、鋼片から外れた空間で鋼片厚み方向
と平行に形成されるもの(II)、鋼片もまた空間も貫かず
に散逸するもの(III) になる。これらの誘導磁束の中
で、鋼板に誘導される電流に寄与するのは鋼片を鋼片厚
み方向に貫く磁束(I) であり、(I) の垂直成分の変化率
の大きさが誘導電流の強度に比例するため、この発明
は、(1) の磁束を多く確保するように工夫を加えたこと
が最大のポイントであると言える。
The induction magnetic flux generated between the magnetic poles of the induction heating coil shown in FIGS. 1 to 3 is roughly divided into a steel slab that penetrates the steel slab in the thickness direction (I). It is formed parallel to the thickness direction (II) and dissipated without passing through the billet or space (III). Among these induced magnetic fluxes, the magnetic flux (I) penetrating the slab in the thickness direction of the slab contributes to the current induced in the steel sheet, and the magnitude of the change in the vertical component of (I) depends on the induced current. It can be said that the most important point of the present invention is that the invention is devised to secure a large amount of magnetic flux in (1).

【0011】すなわち、接合端部(先行鋼片の後端部又
は後行鋼片の先端部)の幅方向端部は周囲が空間で囲ま
れているため、かかる幅方向端部近傍において鋼片を挟
むように配置された磁極間に形成される磁束は、鋼片に
近付くように曲がる。というのは、鋼片の透磁率は空間
の透磁率よりも大きいことから空間を貫いている磁束
は、鋼片に近づくように曲がるのである。そのため、鋼
片を垂直に貫いていた磁束も影響を受け、曲がった経路
で鋼片を貫く。その結果、鋼片を貫く磁束のうち、垂直
成分の強さが接合端部の幅方向中央寄りに比べて減少し
易い。
That is, since the periphery in the width direction of the joining end portion (the rear end portion of the preceding steel slab or the front end portion of the succeeding steel slab) is surrounded by a space, the billet near the widthwise end portion is surrounded by a space. The magnetic flux formed between the magnetic poles disposed so as to sandwich the steel sheet bends to approach the steel slab. This is because the magnetic permeability of the steel slab is larger than the magnetic permeability of the space, so that the magnetic flux penetrating the space bends closer to the steel slab. Therefore, the magnetic flux penetrating the billet vertically is also affected and penetrates the billet in a curved path. As a result, of the magnetic flux passing through the steel slab, the strength of the vertical component tends to decrease as compared to the widthwise center of the joint end.

【0012】一方で、誘導加熱コイルを見ると、該コイ
ルにより誘導された磁束が貫通しているから、鉄心にも
鋼片と同様に誘導電流が生じる。ここにおいて、誘導電
流は、鋼片や鉄心の表面や端部に集中して流れることが
知られていて(表皮効果)、この誘導電流の流れる領域
は、鋼片や鉄心の表面から内部方向への距離(深さ)と
して浸透深さδして一般に定義される。この浸透深さδ
(m) は、
On the other hand, looking at the induction heating coil, since the magnetic flux induced by the coil penetrates, an induction current is also generated in the iron core similarly to the steel slab. Here, it is known that the induced current flows intensively on the surface and the end of the billet or iron core (skin effect), and the region where this induced current flows is inward from the surface of the billet or core. Is generally defined as the penetration depth δ as the distance (depth) of. This penetration depth δ
(m) is

【数3】 で表される。(Equation 3) It is represented by

【0013】したがって、鉄心に誘導された電流につい
ても表皮効果によってコイル横断面の外周近傍に主に流
れる。このような鉄心に流れる誘導電流は、コイルに発
生する交番磁界を打ち消す方向の磁束を発生させるた
め、コイル鉄心の外周近傍では、鋼片を加熱するために
用いられる磁束が鉄心中央部に比べて少なくなる。加え
てコイル鉄心の外周近傍では、前記したような散逸磁束
(III) についても多く生じるから、鉄心の外周近傍と相
対する鋼片に貫通する磁束は少なくなる結果となる。
Accordingly, the current induced in the iron core also flows mainly near the outer periphery of the coil cross section due to the skin effect. The induction current flowing through such an iron core generates a magnetic flux in a direction to cancel the alternating magnetic field generated in the coil.Therefore, near the outer periphery of the coil core, the magnetic flux used to heat the steel slab is compared to the central portion of the core. Less. In addition, near the outer periphery of the coil core,
Since a large amount of (III) also occurs, the magnetic flux penetrating the steel slab facing the vicinity of the outer periphery of the iron core is reduced.

【0014】以上のことから、鋼片の接合端部における
幅方向端部を、幅方向中央部近傍と同様に効率良く加熱
するためには、第1に該端部をコイル外周端及び貫通磁
束流の端から避け、磁束流の内側に配すること、つまり
誘導加熱コイルの磁極を鋼片幅方向端部よりも外方には
み出させることが非常に重要であり、第2に散逸磁束や
磁束の曲がりを小さくするため、貫通磁束の道行を減少
させる、つまりはコイルと鋼片との距離を小さくさせる
ことが重要であると言える。上記の要件を適正に選定す
ることで、鋼片を幅方向端部まで均一に効率良く加熱で
きるようになる。
From the above, in order to efficiently heat the widthwise end of the joint end portion of the steel slab in the same manner as in the vicinity of the center in the widthwise direction, first, the end should be connected to the outer peripheral end of the coil and the penetrating magnetic flux. It is very important to avoid from the end of the flow and arrange inside the magnetic flux flow, that is, to make the magnetic pole of the induction heating coil protrude beyond the end in the width direction of the steel slab. It can be said that it is important to reduce the path of the penetrating magnetic flux, that is, to reduce the distance between the coil and the billet in order to reduce the bending of the coil. By properly selecting the above requirements, the billet can be uniformly and efficiently heated to the widthwise end.

【0015】そこでこの発明では、はみ出し量B(m)
は、浸透深さδとの関係で2.0 ×δ≦Bを満足させるよ
うにする。Bの値が2.0 ×δで計算される値よりも小さ
い場合には、後述する実施例でも明らかなとおり接合面
における幅方向端部の昇温速度が、幅方向中央部に比べ
て著しく低下する結果、接合面にわたる良好な接合が得
られなくなる。
Therefore, in the present invention, the amount of protrusion B (m)
Satisfies 2.0 × δ ≦ B in relation to the penetration depth δ. When the value of B is smaller than the value calculated by 2.0 × δ, the rate of temperature rise at the end in the width direction at the joint surface is significantly lower than that at the center in the width direction, as is clear from the examples described later. As a result, good joining over the joining surface cannot be obtained.

【0016】また誘導加熱コイルの磁極と鋼片との距離
D(m) は、上記はみ出し量Bとの関係でD≦1.5 ×Bを
満足させるようにする。Dの値が1.5 ×Bで計算される
値よりも大きい場合には、後述する実施例でも明らかな
とおり接合面における幅方向端部の昇温速度が、幅方向
中央部に比べて著しく低下する結果、接合面にわたる良
好な接合が得られなくなる。
The distance D (m) between the magnetic pole of the induction heating coil and the steel slab is set so as to satisfy D ≦ 1.5 × B in relation to the above-mentioned protrusion amount B. When the value of D is larger than the value calculated by 1.5 × B, the rate of temperature rise at the end in the width direction at the bonding surface is significantly lower than that at the center in the width direction, as is clear from the examples described later. As a result, good joining over the joining surface cannot be obtained.

【0017】なお、この発明で規定するはみ出し量B
は、鋼片幅方向両端部のそれぞれから磁極がはみ出した
量のうち、いずれか少ない方のはみ出し量で定義する。
同様に、鋼片とコイル(磁極)との間隔Dは、鋼片から
一対の磁極までの距離のうち、いずれか大きい方の間隙
で定義する。
The amount of protrusion B defined in the present invention
Is defined as the amount of protrusion of the smaller one of the amounts of the magnetic pole protruding from both ends in the billet width direction.
Similarly, the distance D between the steel slab and the coil (magnetic pole) is defined by the larger of the distances from the steel slab to the pair of magnetic poles.

【0018】また、上述した2.0 ×δ≦Bを満足させる
こととD≦1.5 ×Bを満足させることとは、いずれか一
方を満足させれば、この発明で所期した鋼片幅方向の均
一加熱が達成できるが、両方を満足させれば、より一層
優れた効果が得られる。
Further, satisfying either 2.0 × δ ≦ B or satisfying D ≦ 1.5 × B, if either one is satisfied, the uniformity in the width direction of the steel slab expected in the present invention is satisfied. Heating can be achieved, but if both are satisfied, an even better effect can be obtained.

【0019】さらに、この発明における誘導電流による
鋼片加熱の工程と、鋼片を相互に押圧する工程との組み
合わせの例としては、 1)先行鋼片の後端部及び後行鋼片の先端部(接合領
域)が接触状態であるか非接触状態であるかの如何にか
かわらず、この領域の温度が目標温度に達した時点で加
熱を停止し、次いで押圧する方法 2)同じく接合領域が接触状態であるか非接触状態であ
るかの如何にかかわらず、この領域の温度が目標温度に
達したならば、加熱は継続したままで押圧を開始する方
法 3)最初から鋼片同志を押圧し、接合領域の加熱も同時
に行う方法 4)最初から鋼片同志を押圧した後、接合領域の加熱を
開始する方法 のいずれの方法でもよい。
Further, examples of the combination of the step of heating the slab by the induced current and the step of pressing the slab mutually according to the present invention include: 1) the rear end of the preceding slab and the front end of the following slab. A method in which the heating is stopped when the temperature of this area reaches the target temperature and then pressed, regardless of whether the part (joining area) is in a contact state or a non-contact state. If the temperature in this area reaches the target temperature, regardless of whether it is in contact or non-contact, press the heating while continuing to heat. 3) Press the billets from the beginning. Then, the joint area is heated simultaneously. 4) Any method of starting the heating of the joint area after pressing the billets from the beginning.

【0020】[0020]

【実施例】図1に示すようなC型鉄心を有する誘導加熱
コイルとして、鋼片に対向する磁極の幅(鋼片幅と平行
な方向の寸法)が異なる複数個の誘導加熱コイルを用意
しはみ出し量Bを種々に変化させて、熱間粗圧延後の冷
片シートバー(SUS 304 、厚み30mm、幅1000mm)を10mm
のギャップを空けて対向させ、誘導加熱した。この加熱
の際、鋼板と誘導加熱コイルとの間隙Dは、0.05m と一
定にして、コイルに印加する交番電流の周波数条件を、
100 Hz、500 Hz、1kHz、10 kHz及び100kHzで行い(投入
電力はいずれも同じ)、鋼片幅方向端部の昇温速度がど
のように変化するのかを調査した。昇温速度の測定に
は、シートバーの幅、長手それぞれの端部から2mmの位
置にK型シース温度計を埋設し、誘導加熱コイルに電流
を3秒間通電してその昇温カーブを記録後、昇温速度
(℃/s)を求めた。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an induction heating coil having a C-shaped iron core as shown in FIG. 1, a plurality of induction heating coils having different widths of magnetic poles facing the steel slab (dimensions in a direction parallel to the width of the steel slab) are prepared. By changing the amount of protrusion B in various ways, the cold strip sheet bar (SUS 304, thickness 30 mm, width 1000 mm) after hot rough rolling is 10 mm.
, And heated by induction. At the time of this heating, the gap D between the steel sheet and the induction heating coil was fixed at 0.05 m, and the frequency condition of the alternating current applied to the coil was
The test was performed at 100 Hz, 500 Hz, 1 kHz, 10 kHz, and 100 kHz (input power was the same), and it was investigated how the heating rate at the end in the width direction of the slab changes. To measure the heating rate, a K-type sheath thermometer was embedded at a position 2 mm from the end of each of the width and length of the sheet bar, a current was applied to the induction heating coil for 3 seconds, and the heating curve was recorded. And the rate of temperature rise (° C./s).

【0021】かくして得られたデータから、磁極のはみ
出し量Bと鋼片幅方向端部との昇温速度との関係につい
て調べた結果を図4に示す。図4において、はみ出し量
Bは、磁場影響距離δとの関係で考え、B/δとしてB
を無次元化することにより、いかなる磁極形状、電源周
波数、鋼片の種類(比透磁率、比抵抗)にも対処可能な
変数で示した。因みに浸透深さδは、100 Hzで49mm、50
0 Hzで22mm、1kHzで15mm、10 kHzで5mm、100kHzで1.5
mmとなり、図4では、各周波数での平均値を示してい
る。また昇温速度は、はみ出し量Bが4.0 ×δである場
合を基準として、他のはみ出し量の場合の昇温速度を、
この基準の昇温速度からの比の形で整理した。
FIG. 4 shows the results of an examination of the relationship between the amount of protrusion B of the magnetic pole and the rate of temperature rise at the end in the width direction of the slab from the data thus obtained. In FIG. 4, the amount of protrusion B is considered in relation to the magnetic field influence distance δ, and B / δ is expressed as B / δ.
Are shown as variables that can deal with any magnetic pole shape, power supply frequency, and type of steel slab (relative magnetic permeability, specific resistance). By the way, the penetration depth δ is 49 mm at 100 Hz, 50
22mm at 0 Hz, 15mm at 1kHz, 5mm at 10kHz, 1.5 at 100kHz
mm, and FIG. 4 shows an average value at each frequency. The heating rate is based on the case where the protrusion amount B is 4.0 × δ, and the heating rate in the case of another protrusion amount is
It was arranged in the form of a ratio from the standard heating rate.

【0022】図4から、浸透深さδの2.0 倍を境にし
て、2.0 倍よりも小さなはみ出し量Bを選定した場合
は、著しく加熱効率が低下することがわかる。このこと
は、コイル鉄心内の磁束影響範囲である外周からδだけ
の幅の影響が、鋼片を垂直に貫く実際の磁束としては、
磁束の散逸、曲がりを含めて2δの影響範囲として現れ
ているといえる。また、δの2.0 倍よりもはみ出し量B
が大きい領域では、磁場の垂直成分の大きさは同じであ
るため、同一の加熱速度を得られることがわかった。し
たがって、2.0 ×δ≦Bを満足させることが、幅方向端
部まで効率良い加熱を達成するための条件であることが
わかった。
From FIG. 4, it can be seen that when the protrusion amount B smaller than 2.0 times the boundary of 2.0 times the penetration depth δ, the heating efficiency is significantly reduced. This means that the effect of the width of δ from the outer circumference, which is the magnetic flux influence range in the coil core, is the actual magnetic flux that penetrates the billet vertically,
It can be said that it appears as the influence range of 2δ including the dissipation and bending of the magnetic flux. Also, the amount of protrusion B beyond 2.0 times δ
In the region where is large, it was found that the same heating rate can be obtained because the magnitude of the vertical component of the magnetic field is the same. Therefore, it was found that satisfying 2.0 × δ ≦ B is a condition for achieving efficient heating up to the end in the width direction.

【0023】次に、コイルと鋼片との間隔Dは磁束の曲
がり、磁束の散逸と密接に関係がある。よって、はみ出
し量Bが小さい場合には、コイルと鋼片との間隔Dも小
さいほうが望ましい。
Next, the distance D between the coil and the steel slab is closely related to the bending of the magnetic flux and the dissipation of the magnetic flux. Therefore, when the amount of protrusion B is small, it is desirable that the distance D between the coil and the billet is also small.

【0024】そこで、はみ出し量Bに対するコイルと鋼
片との間隔Dの比と、昇温速度との関係を調査した。調
査は、前述の実験と同様に図1に示すようなC型鉄心を
有する誘導加熱コイルとして鋼片に対向する磁極の幅
(鋼片幅と平行な方向の寸法)は1.2 m と固定して鋼片
との間隔が種々に異なる複数個の誘導加熱コイルを用意
し、熱間粗圧延後の冷片シートバー(SUS 304 、厚み30
mm、幅1000mm)を10mmのギャップを空けて対向させ、誘
導加熱した。この加熱の際、コイルに印加する交番電流
の周波数条件を、100 Hz、500 Hz、1kHz、10 kHz及び10
0kHzで行い(投入電力はいずれも同じ)、鋼片幅方向端
部の昇温速度がどのように変化するのかを調査した。昇
温速度の測定には、シートバーの幅、長手それぞれの端
部から2mmの位置にK型シース温度計を埋設し、誘導加
熱コイルに電流を3秒間通電してその昇温カーブを記録
後、昇温速度(℃/s)を求めた。
Therefore, the relationship between the ratio of the distance D between the coil and the billet to the amount of protrusion B and the rate of temperature rise was investigated. Investigation was carried out in the same way as in the previous experiment, as shown in Fig. 1, as an induction heating coil having a C-shaped iron core, with the width of the magnetic pole facing the steel slab (dimension in the direction parallel to the steel slab width) fixed at 1.2 m. Prepare a plurality of induction heating coils with various distances from the steel slab and prepare a cold flake sheet bar (SUS 304, thickness 30) after hot rough rolling.
mm, width 1000 mm) were opposed to each other with a gap of 10 mm, and induction heating was performed. During this heating, the frequency conditions of the alternating current applied to the coil were set to 100 Hz, 500 Hz, 1 kHz, 10 kHz and 10 kHz.
The test was performed at 0 kHz (input powers were the same), and it was investigated how the heating rate at the end of the billet width direction changes. To measure the heating rate, a K-type sheath thermometer was embedded at a position 2 mm from the end of each of the width and length of the sheet bar, a current was applied to the induction heating coil for 3 seconds, and the heating curve was recorded. And the rate of temperature rise (° C./s).

【0025】かくして得られたデータから、コイルと鋼
片との間隔Dと、昇温速度との関係について調べた結果
を図5に示す。図5において、コイルと鋼片との間隔D
は、はみ出し量Bとの関係で考え、D/BとしてDを無
次元化した。また、図5では、各周波数での平均値を示
している。図5から明らかなように、D/Bが1.5 を超
えると昇温速度の急激な低下が見られた。これは、D/
Bが1.5 以内では、磁束の垂直性が十分に保証可能な磁
束の道行となっていることを示している。
FIG. 5 shows the result of an examination of the relationship between the interval D between the coil and the billet and the rate of temperature rise from the data thus obtained. In FIG. 5, the distance D between the coil and the billet
Was considered in relation to the amount of protrusion B, and D was made dimensionless as D / B. FIG. 5 shows the average value at each frequency. As is evident from FIG. 5, when D / B exceeds 1.5, a rapid decrease in the heating rate was observed. This is D /
When B is less than 1.5, it indicates that the perpendicularity of the magnetic flux is sufficient to guarantee the magnetic flux.

【0026】[0026]

【発明の効果】この発明では、誘導加熱コイルの幅方向
端部が鋼片幅方向からはみ出す距離Bを適正にし、ま
た、誘導加熱コイルの磁極面とこれに対向する鋼片表面
との距離Dを適正にすることによって、鋼片幅方向にわ
たって均一な加熱を行うことができるようになった。そ
の結果、接合後の連続圧延中に接合部の幅方向端部での
耳割れがなくなり、また、接合の際にも、1〜2kgf/mm
2 程度といった小さな押圧力で接合が可能となり、押圧
用の設備を非常にコンパクトにすることが可能となっ
た。さらに、幅方向端部の加熱のために余計な時間を必
要としなくなり、圧延ピッチの向上も見られた。
According to the present invention, the distance B at which the widthwise end of the induction heating coil protrudes from the width direction of the steel slab is adjusted, and the distance D between the pole face of the induction heating coil and the surface of the steel slab facing the same. By appropriately setting, it was possible to perform uniform heating over the width direction of the billet. As a result, during continuous rolling after joining, edge cracks at the end in the width direction of the joined portion are eliminated, and also at the time of joining, 1-2 kgf / mm
Joining is possible with a small pressing force of about 2 , making it possible to make the pressing equipment very compact. Further, no extra time is required for heating the width direction ends, and the improvement of the rolling pitch was also observed.

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

【図1】この発明における先行鋼片と後行鋼片との接合
領域における誘導加熱コイルの配置状況の一例を示す説
明図である。
FIG. 1 is an explanatory diagram showing an example of an arrangement state of an induction heating coil in a joining region between a preceding slab and a following slab in the present invention.

【図2】この発明における先行鋼片と後行鋼片との接合
領域における誘導加熱コイルの配置状況の他の例を示す
説明図である。
FIG. 2 is an explanatory view showing another example of an arrangement state of an induction heating coil in a joining region between a preceding slab and a following slab in the present invention.

【図3】この発明における先行鋼片と後行鋼片との接合
領域における誘導加熱コイルの配置状況の他の例を示す
説明図である。
FIG. 3 is an explanatory view showing another example of an arrangement of induction heating coils in a joining region between a preceding steel slab and a following steel slab according to the present invention.

【図4】はみ出し量Bと浸透深さδとの比が接合端部の
幅方向端部の昇温速度に及ぼす影響を示すグラフであ
る。
FIG. 4 is a graph showing the effect of the ratio of the protrusion amount B to the penetration depth δ on the rate of temperature rise at the widthwise end of the joint end.

【図5】磁極と鋼片との距離Dとはみ出し量Bとの比が
接合端部の幅方向端部の昇温速度に及ぼす影響を示すグ
ラフである。
FIG. 5 is a graph showing the effect of the ratio of the distance D between the magnetic pole and the steel slab to the amount of protrusion B on the rate of temperature rise at the widthwise end of the joint end.

【符号の説明】[Explanation of symbols]

1 誘導加熱コイル 2 通電コイル 3 鉄心 4 交流電源 5,6,7,8,9,10 鋼片 11,12 誘導加熱コイル DESCRIPTION OF SYMBOLS 1 Induction heating coil 2 Electricity coil 3 Iron core 4 AC power supply 5, 6, 7, 8, 9, 10 Steel billet 11, 12 Induction heating coil

フロントページの続き (72)発明者 天笠 敏明 千葉県千葉市中央区川崎町1番地 川崎 製鉄株式会社 千葉製鉄所内 (72)発明者 二階堂 英幸 千葉県千葉市中央区川崎町1番地 川崎 製鉄株式会社 千葉製鉄所内 (72)発明者 山田 博右 千葉県千葉市中央区川崎町1番地 川崎 製鉄株式会社 千葉製鉄所内 (72)発明者 磯山 茂 千葉県千葉市中央区川崎町1番地 川崎 製鉄株式会社 千葉製鉄所内 (72)発明者 平林 毅 千葉県千葉市中央区川崎町1番地 川崎 製鉄株式会社 千葉製鉄所内 (72)発明者 森本 和夫 広島県広島市西区観音新町4−6−22 三菱重工業株式会社 広島研究所内 (72)発明者 橋本 学夫 兵庫県尼崎市塚口本町8−1−1 三菱 電機株式会社 伊丹製作所内 (72)発明者 坂本 秀夫 兵庫県尼崎市塚口本町8−1−1 三菱 電機株式会社 伊丹製作所内 (56)参考文献 特開 平7−164011(JP,A) 特開 平7−299502(JP,A) 特開 平7−328705(JP,A) (58)調査した分野(Int.Cl.6,DB名) B21B 15/00 B21B 1/26 B23K 20/00 340 H05B 6/10 381 Continuing from the front page (72) Inventor Toshiaki Amagasa 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (72) Inventor Hideyuki Nikaido 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corp. Inside the steelworks (72) Hirohiro Yamada, inventor 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Kawasaki Steel Corporation Co., Ltd.Chiba Works (72) Inventor Shigeru Isoyama 1, Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corp. In-house (72) Inventor Takeshi Hirabayashi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Kawasaki Steel Corporation Chiba Works (72) Inventor Kazuo Morimoto 4-6-22 Kanon Shinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. In-house (72) Inventor Hiroo Hashimoto 8-1-1, Tsukaguchi-Honmachi, Amagasaki-shi, Hyogo Mitsubishi Electric Corporation Itami Works (72) Inventor Hideo Sakamoto 8-1-1, Tsukaguchi-Honmachi, Amagasaki-shi, Hyogo Mitsubishi Electric Corporation Itami In the factory (56) JP-A-7-164011 (JP, A) JP-A-7-299502 (JP, A) JP-A-7-328705 (JP, A) (58) Fields investigated (Int. Cl. 6 , DB name) B21B 15/00 B21B 1/26 B23K 20/00 340 H05B 6/10 381

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項1】 圧延機入側の圧延ラインにて、先行して
ラインを搬送させる鋼片の後端部と、この鋼片に追随し
て搬送させる鋼片の先端部とを対向させ、この対向させ
た鋼片の後端部及び先端部を挟んで磁極を対向させた1
対以上の誘導加熱コイルを配置して、このコイルの磁極
から該鋼片の厚み方向に貫通する交番磁界を印加するこ
とより鋼片に生ずる誘導電流により該鋼片を加熱する工
程と、該鋼片を相互に押圧する工程との組み合わせによ
り鋼片を接合する方法において、 上記誘導加熱コイルの磁極を鋼片幅方向端部よりも外方
にはみ出させ、鋼片から磁極が幅方向にはみ出す長さB
(m) を誘導電流の浸透深さδとの関係で次式 【数1】 を満足させることを特徴とする鋼片の接合方法。
At the rolling line on the entry side of the rolling mill, the rear end of the billet to be conveyed in advance and the leading end of the billet to be conveyed following this bill are opposed to each other. The magnetic poles are opposed to each other with the rear end and the front end of the opposing steel slab interposed.
A step of arranging at least one pair of induction heating coils and heating the slab by an induction current generated in the slab by applying an alternating magnetic field penetrating in the thickness direction of the slab from the magnetic pole of the coil; A method for joining steel slabs in combination with a step of mutually pressing the slabs, wherein a length of the magnetic pole of the induction heating coil protrudes outward from an end of the slab in the width direction, and a magnetic pole protrudes from the slab in the width direction. Sa B
(m) is related to the penetration depth δ of the induced current by the following equation. A method for joining billets, characterized by satisfying the following.
【請求項2】 圧延機入側の圧延ラインにて、先行して
ラインを搬送させる鋼片の後端部と、この鋼片に追随し
て搬送させる鋼片の先端部とを対向させ、この対向させ
た鋼片の後端部及び先端部を挟んで磁極を対向させた1
対以上の誘導加熱コイルを配置して、このコイルの磁極
から該鋼片の厚み方向に貫通する交番磁界を印加するこ
とより鋼片に生ずる誘導電流により該鋼片を加熱する工
程と、該鋼片を相互に押圧する工程との組み合わせによ
り鋼片を接合する方法において、上記誘導加熱コイルの
磁極を鋼片幅方向端部よりも外方にはみ出させ、鋼片か
ら磁極が幅方向にはみ出す長さB(m) を鋼片と磁極との
間隔D(m) との関係で D≦1.5 ×B を満足させることを特徴とする鋼片の接合方法。
2. In the rolling line on the entry side of the rolling mill, the rear end of the billet to be conveyed in advance and the leading end of the billet to be conveyed following this billet are opposed to each other. The magnetic poles are opposed to each other with the rear end and the front end of the opposing steel slab interposed therebetween.
A step of arranging at least one pair of induction heating coils and heating the slab by an induction current generated in the slab by applying an alternating magnetic field penetrating in the thickness direction of the slab from the magnetic pole of the coil; A method for joining steel slabs in combination with a step of mutually pressing the slabs, wherein the magnetic poles of the induction heating coil protrude outward from the ends of the slabs in the width direction, and the magnetic poles protrude from the slabs in the width direction. A method for joining steel slabs, wherein the relation B (m) satisfies D ≦ 1.5 × B in relation to the distance D (m) between the steel slab and the magnetic pole.
JP5316750A 1993-12-16 1993-12-16 How to join billets Expired - Fee Related JP2981097B2 (en)

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JP5316750A JP2981097B2 (en) 1993-12-16 1993-12-16 How to join billets

Publications (2)

Publication Number Publication Date
JPH07164017A JPH07164017A (en) 1995-06-27
JP2981097B2 true JP2981097B2 (en) 1999-11-22

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5628731B2 (en) * 2011-03-31 2014-11-19 三井造船株式会社 Induction heating device
KR101294918B1 (en) * 2011-12-28 2013-08-08 주식회사 포스코 Heater, Transverse Flux Induction Heater, Rolling Line and Heating Method

Also Published As

Publication number Publication date
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