JPH0318538B2

JPH0318538B2 -

Info

Publication number: JPH0318538B2
Application number: JP61098040A
Authority: JP
Inventors: Katsuo Kinoshita; Koji Hosoya; Kenji Murata; Masao Oguchi; Akio Ejima
Original assignee: Kawasaki Steel Corp
Current assignee: JFE Steel Corp
Priority date: 1986-04-30
Filing date: 1986-04-30
Publication date: 1991-03-12
Also published as: JPS62254954A

Description

【発明の詳細な説明】[Detailed description of the invention]

（産業上の利用分野）本発明は、連続鋳造における鋳型内溶鋼流動の
抑制方法に関し、特に低炭素Alキルド鋼を連続
鋳造（彎曲型スラブ連鋳）する場合において、ス
ループツトを上げて高速鋳造をしても、介在物の
集積捕捉やパウダーおよび気泡の巻込みなどを増
大させてUT欠陥やフクレなどの製品欠陥を招く
ことがないように、磁極ブレーキ（EMBR）を
利用して鋳型内へのノズルからの溶鋼吐出流を抑
制することとしたその改良方法についての提案で
ある。（従来の技術）一般に、上述した製品欠陥を防止する技術とし
ては、炉外精練による溶鋼清浄化の強化、タ
ンデイツシユのシール強化による再酸化の防止、
溶鋼鋳込み温度の上昇による介在物の浮上促
進、大容量タンデイツシユによる取鍋スラグや
タンデイツユパウダーの巻込み防止、彎曲型ス
ラブ連鋳機において垂直部を採用することによる
鋳型内での介在物浮上促進、浸漬ノズルの形態
を改善することによる介在物やパウダーの巻き込
みの防止、浸漬ノズルの吐出口前方に邪魔板を
設けて、介在物を捕捉したり吐出噴流が溶鋼プー
ル中に深く浸入したりするのを防止する手段など
が知られている。しかし、これらの既知の方法は、要求される製
品の品質レベルや要求生産量に対応した生産プロ
セスにおいて、溶鋼中での清浄性を向上させるに
は限界があつて、溶鋼の洗浄化に対して完全なも
のとはなり得ない。また、鋳型内にまで持込まれ
た介在物や巻き込まれたモールドパウダーは単位
時間当たりのスループツトがある限界値を超える
と完全な浮上は不可能となつて鋼中に捕捉される
結果となる。これに対して従来、それ以前の既知技術が抱え
る欠点を克服する方法として、スラブ連鋳機の鋳
型に電磁石を設置し、浸漬ノズルからの溶鋼吐出
噴流に対してそれに垂直な方向の磁界を付与し、
もつて溶鋼中に誘導される電流と磁界との相互作
用によつて生ずるローレンツ力で溶鋼流動を制動
し、前記吐出噴流が溶鋼プール中に深く浸入する
のを抑制し、それによつてモールドパウダーの巻
込みを防止するとともに溶鋼中に持ち込まれた介
在物の浮上を促進するという方法が提案された。
（J.Nagai、K.Suzuki、S.Kozima and S.
Kallberg、Iron Steel Eng.May（1984）p.41−
p.47）。この方法においては、ローレンツ力による溶鋼
の制動作用は流速に比例するため吐出力が大きい
高速鋳造時ほど効果を発揮すると云われている。（発明が解決しようとする問題点）上記従来技術である静磁界付与による溶鋼制動
法は、モールドパウダーの巻込みに起因するUT
欠陥を著しく軽減するとともに彎曲型連鋳機にお
いて度々経験するところの1/4集積帯における介
在物捕捉をも著しく減少する点で優れた技術であ
るということができる。ところが、低Ｃ−Alキルド鋼の連続鋳造の場
合、ノズル詰まりを防止する目的で上ノズルおよ
びスライデイングノズルからArガスを吹き込ん
でいるため、このArガスが気泡となつて溶鋼噴
出流に巻込まれ、溶鋼プール中に深く浸入して微
細なAl₂O₃粒とともに鋳片中に捕捉される。この
Al₂O₃粒を含有する気泡は熱延および冷延段階で
圧着せず、冷延にひきつづく連続焼鈍中にフクレ
疵となつて出現し、かなりの頻度で製品不良を生
じさせていた。このフクレ疵の発生に対しては、
従来の上記溶鋼制動法（EMBR法）を用いても、
出現の頻度はかなり軽減するものの完全に無くす
ことはできない。それはEMBR法による溶鋼吐出噴流の制動力
が不充分であつて、EMBRを印加してもなお溶
鋼吐出噴流が気泡を伴つたまま溶鋼プール中に侵
入し微細なAl₂O₃粒とともに鋳片中に捕捉される
ためと考えられる。一般に、一様磁束中を横切つて速度〓で運動す
る流体（導体）に誘導される電流〓と、該流体に
働く制動力Ｆは、それぞれ次式で与えられる。〓＝σ（〓×〓） (1) 〓＝〓×〓＝σ（〓×Ｂ）×〓 (2) ここでσ：電気伝導度〓：磁束密度従つて、より一層制動力を増加しようとすれ
ば、磁束密度Ｂを増加させなければならない。そ
して通常静磁界を得る際に磁石を用いる場合は、
対向磁極間距離を一定にして磁束密度を大きくし
ようとすると、磁極（面積）を大きくすることが
必要である。また、定常状態においては、流体（導体）中で
の誘導電流は連続していることが必要であり、流
体中で閉回路を形成して流れなければならない。さらに、該誘導電流は磁束の向きに垂直な面内
で流れなければならない。すなわち、一般に対向
する磁極に挟まれた空間においては、鋳型の厚さ
方向に沿う磁束の向きはほぼ一定である。また、
ノズル吐出口から噴出する溶鋼吐出流は、一般に
幅方向に凸状の流速分布を有しているが、この溶
鋼流が静磁場に突入すると、磁場入側での磁束密
度勾配の影響により所謂ハルトマン流となつて鋳
型の厚さ方向で該流速分布は均一化されることに
なる。従つて鋳型の厚さ方向に沿うほぼ一定の磁
束と、同じく厚さ方向に沿う溶鋼の均一速度分布
のために磁束に平行な面内における誘導電流は一
方向にのみ誘導されてこの面内で閉回路を形成す
ることができない。要するに、誘導電流は第１図
に示すように磁束の向きに対し垂直な面内で形成
しなければならないのである。なお、図示の符号
１は浸漬ノズル、１ａはノズル吐出口、２は磁
極、３は溶鋼、４は鋳型、５はメニスカスであ
る。さて、上述したように磁束密度の増大を果たす
には、磁極２の面積を大きくすればよいが、それ
では第２図に示すように、誘導電流ｉの閉回路は
流路距離がどんどん大きくなり、抵抗が増加して
誘導電流ｉは期待したほど大きくはならない。しかも第３図に示すように、鋳型４の幅寸法に
比較して磁極面積が大き過ぎたり、磁極２の位置
が溶鋼メニスカス（第３図ｃ）５や鋳型短辺（第
３図ｂ）に掛るように配置されている場合には、
誘導電流の閉回路の形成が著しく阻外され、
EMBRによる溶鋼制動効果が極端に減殺されて
しまう。（問題点を解決するための手段）以上説明したような従来技術が現在抱えている
問題点に対し本発明者らはEMBRの基本原理に
立返し以下に述べるような着想の下に発明を完成
するに至つた。一般に、溶鋼の流れ（吐出噴流）に鎖交する磁
束の向きは、右向きでも左向きでも溶鋼流に対し
同一方向の制動力を発生する。しかも、この磁束
の向きが反転すると誘導電流の向きも反転する。
このような原理を利用して以下に述べるように構
成すると、誘導電流に近距離閉回路を形成させる
ことができる。すなわち、第４図に示すことから
明らかなように、ノズル吐出口１ａからでた溶鋼
流は、先ず、溶鋼流の進行方向に向かつて左から
右に向かう磁束〓（静磁場）を通過するので下向
きの誘導電流ｉが生じ、この誘導電流ｉと磁束〓
との相互作用により制動力〓を受けて減速するこ
とになるから制動抑制される。こうして吐出流が
減速した溶鋼流はひきつづき次の磁極間隙（静磁
場）に入り、右から左に向かう磁束〓′を通過し
て上向きの誘導電流i′を生じ、この誘導電流i′と
磁束〓′との相互作用により制動力〓′を受けてさ
らに減速させる。このようにして、溶鋼吐出流の
方向に並ぶ２対の磁極間でそれぞれ誘導された電
流ｉ、i′は、向きが反対で容易に近距離閉回路を
形成し易く、EMBRの効果を有効に実現するこ
とが可能である。すなわち、かような着想を実現するための本発
明は、スラブの連続鋳造に際し、鋳型長辺の背後
に鋳型を隔てて対向する互いに異極の磁極を配設
して、鋳型内の溶鋼浴面下にて鋳型短辺に向かい
開口する浸漬ノズルの該開口からこの鋳型内に吐
出する溶鋼噴流の経路に対して鎖交する方向の静
磁界を付与することにより生ずるローレンツ力で
溶鋼の流動を抑制するようにした鋳型内溶鋼流動
の抑制方法において、上記磁極を、複数対として
上記溶鋼噴流の経路に沿つて互いに極性を異なら
せて近接配設して、溶鋼噴流中に生起される誘導
電流の経路の長さを短小にしたことを特徴とする
連続鋳造における鋳型内溶鋼流動の抑制方法を要
旨構成とする。なお、並列させる磁極対の配置は、あまり離れ
ると最短距離で個別に閉回路を構成して第４図に
示すような閉回路を構成しなくなるので接近して
いることが望ましく、また第４図に示すようにコ
の字形磁極鉄芯にすることが必須ではないが、コ
の字形にするのは望ましい態様である。（作用）本発明においてノズル吐出口１ａからの溶鋼流
に付与するための静磁界を発生させる磁極につい
ては、磁束の向きが交互に反転するように配置し
た一対のものを多数段にわたつて列設することが
可能である。しかしながら、スラブ連鋳機の鋳型
４の厚さと幅から、効果的な磁極２の寸法を選定
するならば、ノズル１を挟む片側に２対の磁極を
配設して２段の磁束を供給することが適当と考え
られる。このようにして、例えば厚さ220mm、幅850〜
1550mmのスラブ断面を有するスラブ連鋳機の場合
について、配置すべきEMBRの好適配置の図を
第５図に示した。この場合磁極鉄芯２ａの断面積
150×150mm、対向する磁極２，２′間距離260mm、
隣接する磁極間距離350mm、対向する磁極間中心
での磁束密度Ｂ最大1200ガウスである。なお比較のために従来型のEMBRの構成図を
第６図に示すが、この場合の磁極鉄芯２ａの断面
積300×300mm、対向する磁極間距離260mm、隣接
する磁極間距離850mm、対向する磁極間中心での
磁束密度Ｂ最大3500ガウスである。（実施例）例１スラブ断面寸法220×（850〜1550）mmの彎曲型
（半径12.5ｍ）のスラブ連鋳機において、片側の
No.１ストランドに第６図に示した従来型の
EMBRを配置し、もう片方のNo.２ストランドに
は第５図にしめしたEMBRを配置した。 250t上底吹き転炉で吹錬し、その後脱ガス処理
をした極低炭素Alキルド鋼（Ｃ＜0.0030％）を、
スループツト2.8〜3.5t／min、パツクスガス
（Ar）吹込み量（８〜10／min）、浸漬ノズル
逆Y4゜型、スラブ幅1025〜1550mmの条件で約800
ヒート鋳造し、連続焼鈍後のライン検査でフクレ
の発生率を比較した。その結果を表１に示す。 (Industrial Application Field) The present invention relates to a method for suppressing the flow of molten steel in a mold in continuous casting, and in particular, in the case of continuous casting of low carbon Al-killed steel (continuous curved slab casting), the throughput is increased to achieve high-speed casting. To prevent product defects such as UT defects and blisters from accumulating and trapping inclusions and entraining powder and air bubbles, magnetic pole brakes (EMBR) are used to prevent damage to the mold. This is a proposal for an improvement method that suppresses the flow of molten steel discharged from the nozzle. (Prior art) In general, techniques for preventing the above-mentioned product defects include strengthening molten steel cleaning through outside furnace refining, preventing reoxidation by strengthening the seal of the tundish, and
Promoting the levitation of inclusions by increasing the molten steel casting temperature, preventing the entrainment of ladle slag and tandate powder by using a large-capacity tundish, and surfacing inclusions in the mold by adopting a vertical section in a curved continuous slab caster. Prevention of inclusions and powder entrainment by improving the shape of the immersion nozzle, and installing a baffle plate in front of the discharge port of the immersion nozzle to trap inclusions and prevent the discharge jet from penetrating deeply into the molten steel pool. There are known means to prevent this from happening. However, these known methods have limitations in improving the cleanliness of molten steel in a production process that corresponds to the required product quality level and required production volume. It cannot be perfect. In addition, inclusions brought into the mold and mold powder rolled up cannot be completely floated when the throughput per unit time exceeds a certain limit value, resulting in being trapped in the steel. Conventionally, as a method to overcome the drawbacks of previously known technologies, an electromagnet was installed in the mold of a continuous slab caster to apply a magnetic field perpendicular to the jet of molten steel discharged from the immersion nozzle. death,
The flow of the molten steel is braked by the Lorentz force generated by the interaction between the current induced in the molten steel and the magnetic field, and the discharge jet is suppressed from penetrating deeply into the molten steel pool. A method has been proposed that prevents entrainment and promotes the floating of inclusions brought into the molten steel.
(J.Nagai, K.Suzuki, S.Kozima and S.
Kallberg, Iron Steel Eng. May (1984) p.41−
p.47). In this method, the braking action of the molten steel by the Lorentz force is proportional to the flow velocity, so it is said to be more effective during high-speed casting where the discharge force is large. (Problems to be Solved by the Invention) The conventional technique described above, which is a method of braking molten steel by applying a static magnetic field, has problems with UT caused by entrainment of mold powder.
It can be said that this is an excellent technology in that it significantly reduces defects and also significantly reduces inclusion trapping in the 1/4 accumulation zone, which is often experienced in curved continuous casting machines. However, in the case of continuous casting of low C-Al killed steel, Ar gas is blown from the upper nozzle and sliding nozzle to prevent nozzle clogging, so this Ar gas becomes bubbles and gets caught up in the molten steel jet. , it penetrates deeply into the molten steel pool and is captured in the slab together with fine Al ₂ O ₃ grains. this
Bubbles containing _three Al ₂ O grains were not compressed during hot rolling and cold rolling, and appeared as blistering defects during continuous annealing following cold rolling, resulting in product defects quite frequently. For the occurrence of this blistering,
Even if the conventional molten steel braking method (EMBR method) is used,
Although the frequency of occurrence can be reduced considerably, it cannot be completely eliminated. This is because the braking force of the molten steel discharge jet by the EMBR method is insufficient, and even after applying EMBR, the molten steel discharge jet enters the molten steel pool with air bubbles, and the fine Al ₂ O ₃ grains are mixed into the slab. This is thought to be because it is captured by Generally, the current 〓 induced in a fluid (conductor) moving at a speed 〓 across a uniform magnetic flux and the braking force F acting on the fluid are given by the following equations. 〓=σ(〓×〓) (1) 〓=〓×〓=σ(〓×B)×〓 (2) where σ: Electrical conductivity 〓: Magnetic flux density Therefore, trying to further increase the braking force Then, the magnetic flux density B must be increased. When using a magnet to obtain a static magnetic field,
In order to increase the magnetic flux density while keeping the distance between opposing magnetic poles constant, it is necessary to increase the magnetic poles (area). Furthermore, in a steady state, the induced current in the fluid (conductor) needs to be continuous and must flow forming a closed circuit in the fluid. Furthermore, the induced current must flow in a plane perpendicular to the direction of the magnetic flux. That is, in general, in a space between opposing magnetic poles, the direction of magnetic flux along the thickness direction of the mold is approximately constant. Also,
The molten steel discharge flow ejected from the nozzle outlet generally has a convex flow velocity distribution in the width direction, but when this molten steel flow enters a static magnetic field, it undergoes a so-called Hartmann phenomenon due to the influence of the magnetic flux density gradient on the magnetic field entrance side. The flow velocity distribution becomes uniform in the thickness direction of the mold. Therefore, due to the almost constant magnetic flux along the thickness direction of the mold and the uniform velocity distribution of the molten steel along the thickness direction, the induced current in the plane parallel to the magnetic flux is induced only in one direction, and within this plane. Unable to form a closed circuit. In short, the induced current must be formed in a plane perpendicular to the direction of magnetic flux, as shown in FIG. In addition, the reference numeral 1 in the figure is an immersion nozzle, 1a is a nozzle discharge port, 2 is a magnetic pole, 3 is molten steel, 4 is a mold, and 5 is a meniscus. Now, as mentioned above, in order to increase the magnetic flux density, it is sufficient to increase the area of the magnetic pole 2, but then, as shown in Fig. 2, the flow path distance of the closed circuit of the induced current i becomes increasingly large, The resistance increases and the induced current i does not become as large as expected. Moreover, as shown in Fig. 3, the magnetic pole area is too large compared to the width dimension of the mold 4, or the position of the magnetic pole 2 is too close to the molten steel meniscus (Fig. 3 c) 5 or the short side of the mold (Fig. 3 b). If it is arranged so that it hangs,
The formation of a closed circuit of induced currents is significantly blocked,
The molten steel braking effect of EMBR is drastically reduced. (Means for solving the problems) In order to solve the problems currently faced by the conventional technology as explained above, the present inventors went back to the basic principles of EMBR and completed the invention based on the ideas described below. I came to the conclusion. Generally, the direction of the magnetic flux interlinking with the flow of molten steel (discharge jet) generates a braking force in the same direction on the flow of molten steel, whether it is directed to the right or to the left. Moreover, when the direction of this magnetic flux is reversed, the direction of the induced current is also reversed.
When configured as described below using such a principle, it is possible to form a short-distance closed circuit in an induced current. That is, as is clear from FIG. 4, the molten steel flow coming out of the nozzle discharge port 1a first passes through a magnetic flux (static magnetic field) that moves from left to right in the direction of travel of the molten steel flow. A downward induced current i is generated, and this induced current i and magnetic flux 〓
Due to the interaction with the vehicle, the vehicle receives a braking force and decelerates, so braking is suppressed. The molten steel flow whose discharge flow has been decelerated in this way continues to enter the next magnetic pole gap (static magnetic field), passes through the magnetic flux 〓′ directed from right to left, and generates an upward induced current i′, and this induced current i′ and the magnetic flux 〓 Due to the interaction with ′, the braking force 〓′ is received and the speed is further decelerated. In this way, the currents i and i′ respectively induced between the two pairs of magnetic poles aligned in the direction of the molten steel discharge flow are opposite in direction and easily form a short-distance closed circuit, making the effect of EMBR effective. It is possible to achieve this. In other words, the present invention aims to realize such an idea by arranging magnetic poles of different polarities behind the long sides of the mold and facing each other across the mold, so that the surface of the molten steel bath in the mold is The flow of molten steel is suppressed by the Lorentz force generated by applying a static magnetic field in a direction interlinking with the path of the molten steel jet discharged into the mold from the opening of the immersion nozzle that opens toward the short side of the mold at the bottom. In the method for suppressing the flow of molten steel in a mold, a plurality of pairs of magnetic poles are disposed close to each other with different polarities along the path of the molten steel jet, thereby suppressing the induced current generated in the molten steel jet. The gist of the present invention is a method for suppressing the flow of molten steel in a mold in continuous casting, which is characterized by reducing the length of the path. In addition, it is desirable that the parallel magnetic pole pairs be placed close together, as if they are too far apart, they will form individual closed circuits at the shortest distance and will no longer form a closed circuit as shown in Figure 4. Although it is not essential to have a U-shaped magnetic pole iron core as shown in the figure, it is desirable to have a U-shaped magnetic pole core. (Function) In the present invention, for the magnetic poles that generate the static magnetic field to be applied to the molten steel flow from the nozzle discharge port 1a, pairs of magnetic poles are arranged in multiple stages so that the direction of magnetic flux is alternately reversed. It is possible to set However, if the effective dimensions of the magnetic poles 2 are selected based on the thickness and width of the mold 4 of the continuous slab casting machine, two pairs of magnetic poles should be arranged on one side of the nozzle 1 to supply two stages of magnetic flux. This is considered appropriate. In this way, for example, thickness 220mm, width 850~
For the case of a continuous slab caster having a slab cross section of 1550 mm, a diagram of the preferred arrangement of EMBRs is shown in Fig. 5. In this case, the cross-sectional area of the magnetic pole iron core 2a
150×150mm, distance between opposing magnetic poles 2 and 2' 260mm,
The distance between adjacent magnetic poles is 350 mm, and the maximum magnetic flux density B at the center between opposing magnetic poles is 1200 Gauss. For comparison, a configuration diagram of a conventional EMBR is shown in Figure 6. In this case, the cross-sectional area of the magnetic pole core 2a is 300 x 300 mm, the distance between opposing magnetic poles is 260 mm, the distance between adjacent magnetic poles is 850 mm, and The maximum magnetic flux density B at the center between the magnetic poles is 3500 Gauss. (Example) Example 1 In a curved slab continuous casting machine (radius 12.5 m) with slab cross-sectional dimensions of 220 x (850 to 1550) mm, one side
The conventional type shown in Figure 6 was applied to the No. 1 strand.
EMBR was placed on the other No. 2 strand, and the EMBR shown in Figure 5 was placed on the other No. 2 strand. Ultra-low carbon Al-killed steel (C<0.0030%) that is blown in a 250t top-bottom blowing converter and then degassed.
Approximately 800 with a throughput of 2.8 to 3.5 t/min, a gas (Ar) injection rate (8 to 10/min), an immersion nozzle of inverted Y4° type, and a slab width of 1025 to 1550 mm.
Heat casting was performed, and the rate of blistering was compared in a line inspection after continuous annealing. The results are shown in Table 1.

【表】例２実施例１と同じ仕様で電縫管素材を各ストラン
ドとも約50ヒート鋳造し、造管後のパイプシーム
部欠陥発生率を比較した。第７図にこの結果をを
示す。またこの欠陥部位を冶金的に調査した結
果、その多くが連鋳パウダー系の介在物であるこ
とが判明した。（発明の効果）以上説明したように本発明溶鋼流動の抑制方法
によれば、低炭素Alキルド鋼の如きものを高速
鋳造する場合であつても、UT欠陥、ブリスタ
ー、フクレ等の製品欠陥を著しく減少させること
ができる。[Table] Example 2 Each strand of electric resistance welded pipe material was heat-cast approximately 50 times with the same specifications as in Example 1, and the incidence of defects at the pipe seam after pipe production was compared. Figure 7 shows the results. Further, as a result of metallurgical investigation of these defective parts, it was found that most of them were inclusions of continuously cast powder. (Effects of the Invention) As explained above, according to the method for suppressing molten steel flow of the present invention, product defects such as UT defects, blisters, and blisters can be prevented even when high-speed casting is performed on materials such as low carbon Al-killed steel. can be significantly reduced.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図のａ，ｂは、EMBRの原理図、第２図
のａ，ｂは、EMBRの磁極の大きさが異なる場
合の誘導電流の流れを示す説明図、第３図のａ，
ｂ，ｃは、磁極の配置が異なる場合の誘導電流の
流れを示す説明図、第４図および第５図のａ，ｂ
は、本発明方法にかかる磁極配置の一例を示す部
分切欠き斜視図および略線図、第６図のａ，ｂ
は、従来例の磁極配置例の説明図、第７図は、実
施例２のUT欠陥発生率を説明するグラフであ
る。１……浸漬ノズル、１ａ……ノズル吐出口、２
……磁極、２ａ……磁極鉄芯、２ｂ……磁極コイ
ル、３……溶鋼、４……鋳型、５……メニスカ
ス。 Figures a and b in Figure 1 are diagrams of the principle of EMBR, Figures a and b in Figure 2 are explanatory diagrams showing the flow of induced current when the sizes of the magnetic poles of EMBR are different, and Figures a and b in Figure 3 are
b, c are explanatory diagrams showing the flow of induced current when the arrangement of magnetic poles is different; a, b in Figs. 4 and 5;
are a partially cutaway perspective view and a schematic diagram showing an example of magnetic pole arrangement according to the method of the present invention, and a and b in FIG.
is an explanatory diagram of a conventional magnetic pole arrangement example, and FIG. 7 is a graph illustrating the UT defect incidence rate of Example 2. 1...Immersion nozzle, 1a...Nozzle discharge port, 2
... Magnetic pole, 2a... Magnetic pole iron core, 2b... Magnetic pole coil, 3... Molten steel, 4... Mold, 5... Meniscus.

Claims

【特許請求の範囲】１スラブの連続鋳造に際し、鋳型長辺の背後に
鋳型を隔てて対向する互いに異極の磁極を配設し
て、鋳型内の溶鋼浴面下にて鋳型短辺に向かい開
口する浸漬ノズルの該開口からこの鋳型内に吐出
する溶鋼噴流の経路に対して鎖交する方向の静磁
界を付与することにより生ずるローレンツ力で溶
鋼の流動を抑制するようにした鋳型内溶鋼流動の
抑制方法において、上記磁極を、複数対として上記溶鋼噴流の経路
に沿つて互いに極性を異ならせて近接配設して、
溶鋼噴流中に生起される誘導電流の経路の長さを
短小にしたことを特徴とする連続鋳造における鋳
型内溶鋼流動の抑制方法。[Claims] 1. When continuously casting slabs, magnetic poles of different polarity are arranged behind the long side of the mold and face each other across the mold, and are placed under the surface of the molten steel bath in the mold and facing toward the short side of the mold. The flow of molten steel in the mold is suppressed by the Lorentz force generated by applying a static magnetic field in a direction interlinking with the path of the molten steel jet discharged from the opening of the immersion nozzle into the mold. In the suppression method, a plurality of pairs of magnetic poles are disposed close to each other along the path of the molten steel jet with different polarities,
A method for suppressing molten steel flow in a mold in continuous casting, characterized by shortening or shortening the length of an induced current path generated in a molten steel jet.