JPH03138053A - Method for supplying molten steel in continuous casting - Google Patents

Abstract

PURPOSE:To restrain variation of molten steel surface and to reduce involution of powder by setting a submerged nozzle arranging a discharging hole for molten steel only to one side of side face as shifting from the center in width direction of a mold and supplying the molten steel into the mold as facing the above discharging hole to the center direction. CONSTITUTION:Only one of the discharging hole 3a is arranged to the submerged nozzle 3 and the submerged nozzle 3 is set as shifting from the center in the width direction of the mold and the discharging hole is faced to the center direction in width of the mold. In order to make flow velocity at the time of discharging the molten steel small, cross sectional area of the discharging hole is made to large. Discharging angle of the discharging hole is made to downward and casting angle is made to larger as larger casting velocity is. By setting distance between the discharging hole and short side face in the mold hitting collision flow to large, the collision flow to solidified face can be made to small. In this result, the variation of molten steel surface is made to small and the involution of powder is restrained and inclusion is floated up and removed without involving to deep position. By this method, the cast having good cleanness can be produced.

Description

【発明の詳細な説明】 （イ）産業上の利用分野 本発明は、鋼の連［１！造において、介在物の少ない清
浄性の良好な鋳片を得るための給湯方法に関するもので
ある。DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention is directed to steel series [1! The present invention relates to a hot water supply method for obtaining cast slabs with few inclusions and good cleanliness in manufacturing.

（ロ）従来技術 連続鋳造方法では、溶湯タンデイツシュから浸漬ノズル
を経て鋳型内へ注入され、鋳型と接する外側から凝固シ
ェルを生成し鋳片として引き抜かれていく、鋳型への溶
鋼の注入方法を第６図に示す、ａ型ｌ内の溶鋼２の湯面
７のレベルは、レベル計（過流式距離計等）８を用いて
タンティッシュ（図示せず）のスライディング・ノズル
やストッパ（図示せず）の開度を制御して給湯量を調節
し、はぼ一定に保たれている。(b) In the conventional continuous casting method, the molten steel is injected into the mold from the tundish through an immersion nozzle, and a solidified shell is generated from the outside in contact with the mold, which is then pulled out as a slab. The level of the molten steel surface 7 of the molten steel 2 in Type A L shown in Figure 6 can be determined using a level meter (overflow distance meter, etc.) 8 using a sliding nozzle or stopper (not shown) of a tongue tissue (not shown). The amount of hot water supplied is controlled by controlling the opening of the water heater, and the amount of hot water is maintained at a constant level.

溶鋼２の湯面７上には、パウダ４が添加されている。パ
ウダ４は、溶１１１２の熱で溶融して鋳型１と凝固シェ
ルとの間に入って潤滑剤として働いたり、溶＃４５の湯
面７がら熱が逃げるのを防ぐ保温剤の役割も果たしてい
る。Powder 4 is added to the surface 7 of the molten steel 2. Powder 4 is melted by the heat of the melt 1112 and enters between the mold 1 and the solidified shell and acts as a lubricant, and also plays the role of a heat insulator that prevents heat from escaping from the surface 7 of the melt #45. .

鋳型１内の溶鋼の流れの状況は、水モデル実験や流体解
析より推定すると、第６図の矢印で示すように、浸漬ノ
ズル３の吐出口３ａよつ流出した溶鋼流２ａ、２ａ′は
鋳型１の側面壁に衝突して上昇流２ｂ、２ｂ′と下降流
２ｃ、２ｃ′とに分かれる。この上昇流２ｂ、２ｂ’は
湯面７に到達して波立ちを生じさせモ、この波立ちは湯
面全体に伝わり、他の波立ちとも重畳してさらに大きく
波立つ、鋳造速度が速くない場合は、溶鋼注入量か少な
いため、吐出流２ａ、２ａ′の速度は小さく、上昇流２
ｂ、２ｂ′も抑制されるため湯面変動はあまり大きくな
い。The state of the flow of molten steel in the mold 1 is estimated from water model experiments and fluid analysis, and as shown by the arrow in Fig. 6, the molten steel flows 2a and 2a' flowing out from the discharge port 3a of the immersion nozzle 3 flow into the mold. 1 and split into upward flows 2b, 2b' and downward flows 2c, 2c'. These rising flows 2b, 2b' reach the hot water surface 7 and cause ripples, which are transmitted to the entire hot water surface and overlap with other ripples to create even larger ripples.If the casting speed is not fast, Since the amount of molten steel injected is small, the velocity of the discharge flows 2a and 2a' is small, and the upward flow 2
Since b and 2b' are also suppressed, the fluctuation in the hot water level is not so large.

生産性を高めるために、鋳造速度を大きくすると、溶鋼
注入量が多くなるため、吐出流２ａ。In order to increase productivity, when the casting speed is increased, the amount of molten steel injected increases, so the discharge flow 2a.

２ａ′、上昇流２ｂ、２ｂ′の速度が大きくなり、湯面
７の波立ち（すなわち変動）が激しくなる。The speeds of the rising flows 2a' and 2b, 2b' increase, and the ripples (ie, fluctuations) of the hot water surface 7 become more intense.

湯面７の変動が大きくなると、湯面上のパウダ４が溶鋼
２中に巻き込まれて凝固シェル５に捕捉される、いわゆ
るノロカミが多発する。ノロカミした鋳片は、圧延後製
品表面に疵が発生する。また、湯面変動が大きいと凝固
シェル５の厚みが不均一になり、厚みの薄い部分で割れ
が発生しやすい。When fluctuations in the hot water level 7 become large, powder 4 on the hot water surface gets caught in the molten steel 2 and is captured by the solidified shell 5, which is a so-called slag. A roughened slab will have defects on the surface of the product after rolling. Further, if the liquid level fluctuates greatly, the thickness of the solidified shell 5 becomes uneven, and cracks are likely to occur in thinner parts.

また、鋳造速度が大きくなると、下降流２ｃ。Moreover, when the casting speed increases, the downward flow 2c.

２ｃ’も大きくなるために、注入溶鋼中に含まれている
酸化物系非金属の介在物が鋳片６の内部に深く巻き込ま
れてしまう、−度深く巻く巻き込まれた介在物は湯面７
にまで浮上することがなく、凝固シェル５に捕捉され、
介在物量が多くなる。2c' also becomes larger, so that the oxide-based nonmetallic inclusions contained in the poured molten steel are deeply rolled into the inside of the slab 6.
The solidified shell 5 does not float up to the surface and is captured by the solidified shell 5.
The amount of inclusions increases.

以上のようなノロカミや介在物の多い鋳片は、圧延後の
製品表面に疵が発生するという問題が生じる。A cast slab with many rough edges and inclusions as described above has a problem in that flaws occur on the surface of the product after rolling.

上記の問題を解決する技術として、浸漬ノズル３の吐出
口３ａを４つ六にする技術が開示されている（特開平１
−１５７７５１号公報）、これは、吐出口の数を増やし
て、吐出流２ａ、２ａ′の流速を小さくし、湯面変動を
抑え、介在物の侵入を抑えることを狙っている。As a technique for solving the above problem, a technique has been disclosed in which the number of discharge ports 3a of the immersion nozzle 3 is four or six (Japanese Patent Application Laid-Open No.
157751), which aims to increase the number of discharge ports, reduce the flow velocity of the discharge flows 2a and 2a', suppress fluctuations in the melt level, and suppress the intrusion of inclusions.

この方法は、浸漬ノズル３内を溶鋼が均一に流れて左右
の吐出口３ａ、３ａ’から均等に流れる（つまり吐出流
速か同じ）場合は、その効果が現れる。しかし、実際に
は浸漬ノズル３の内側に溶鋼中の酸化物等が付着するな
どのために、ノズル内の溶鋼は偏流となり、左右の吐出
口から出る溶１２の吐出速度が異なる、いわゆる片流れ
が生じている。このため、第６図に示すように浸漬ノズ
ル３の左側と右側とで鋳型内の溶鋼流れの挙動は全く異
なり、吐出流速の大きい方では、湯面変動か大きくなる
。This method is effective when the molten steel flows uniformly in the immersion nozzle 3 and flows equally from the left and right discharge ports 3a, 3a' (that is, the discharge flow rate is the same). However, in reality, because oxides in the molten steel adhere to the inside of the immersion nozzle 3, the molten steel inside the nozzle becomes unevenly flowed, and the discharge speed of the molten steel 12 from the left and right discharge ports is different, resulting in so-called one-sided flow. It is occurring. For this reason, as shown in FIG. 6, the behavior of the molten steel flow in the mold is completely different between the left and right sides of the immersion nozzle 3, and the molten steel level fluctuates more on the side where the discharge flow rate is higher.

鋳造速度を大きくすると、溶鋼注入量が多くなり、片流
れも激しくなる。このため、吐出流の大きい側では、湯
面変動も大きくなり、パウダの巻込みか生じ、また、介
在物を奥深くまで巻込んでしまう、このような鋳片は、
圧延後の製品表面に疵か多発するという問題が生じる。When the casting speed is increased, the amount of molten steel injected increases and the one-sided flow becomes more intense. For this reason, on the side where the discharge flow is large, the molten metal level fluctuates greatly, causing powder entrainment, and inclusions being drawn deep into the slab.
A problem arises in that many scratches appear on the surface of the product after rolling.

以上のように、浸漬ノズルからの吐出流が片流れするた
めに、従来の改善方法でも十分な効果が得られなかった
。As described above, because the discharge flow from the immersion nozzle is one-sided, even conventional improvement methods have not been able to obtain sufficient effects.

（ハ）発明が解決しようとする課題 本発明が解決しようとする課題は、高速で連続鋳造をす
る場合において、溶鋼の湯面変動を抑制するとともに、
パウダの巻込みや介在物の巻込みを防止して清浄性の良
好な鋳片を製造することにある。(c) Problems to be Solved by the Invention The problems to be solved by the present invention are to suppress fluctuations in the level of molten steel when performing continuous casting at high speed, and to
The object of the present invention is to prevent the entrainment of powder and inclusions and to produce slabs with good cleanliness.

（ニ）課題を解決するための手段 本発明の鋼の連続鋳造における給湯方法は、鋼を連続的
に鋳造するにさいして、溶鋼槽から鋳型へ溶鋼を供給す
る浸漬ノズルにおいて、溶鋼の吐出口を一方の側面にの
み設けた浸漬ノズルを、鋳型の幅方向にその中心よりず
らせて配置し、前記吐出口を該中心方向に向けて鋳型内
に溶鋼を供給する手段によって、上記課題を解決してい
る。(d) Means for Solving the Problems The hot water supply method for continuous steel casting of the present invention is such that when continuously casting steel, a molten steel discharge port is provided in an immersion nozzle that supplies molten steel from a molten steel tank to a mold. The above problem is solved by means of supplying molten steel into the mold by arranging a submerged nozzle provided only on one side of the mold so as to be offset from the center in the width direction of the mold, and directing the discharge port toward the center. ing.

浸漬ノズルの偏心位置は、鋳型の幅方向において、鋳型
側面から約３０〜１００市程度離れた位置から、鋳型側
面から鋳型幅の１７４程度までの範囲が好ましい。The eccentric position of the immersion nozzle is preferably in the range from about 30 to 100 mm apart from the side surface of the mold to about 174 mm wide from the side surface of the mold in the width direction of the mold.

（ホ）作用 浸漬ノズルからの溶鋼の流れは、浸漬ノズルの内側にＡ
１□０３等の酸化物が付着したノズル詰りゃ、タンデイ
ツシュから鋳型への給湯量を制御しているスライディン
グゲートの移動方向が関係していると考えられている。(e) Operation The flow of molten steel from the immersion nozzle is directed to the inside of the immersion nozzle.
Nozzle clogging due to adhesion of oxides such as 1□03 is thought to be related to the direction of movement of the sliding gate that controls the amount of hot water supplied from the tundish to the mold.

しかし、また片流れの発生機構は明らかではなく、片流
れを防止する方法も明らかではない。However, the mechanism by which one-sided flow occurs is not clear, nor is the method for preventing one-sided flow.

そこで、本発明者等は、片流れが根本的に生じない吐出
口が１つだけの浸漬ノズルに注目した。Therefore, the present inventors focused on a submerged nozzle having only one discharge port, which fundamentally does not cause one-sided flow.

従来のノズル下部に１つだけ吐出口がある場合（第５図
）は、上昇流が小さいため、湯面変動は生じにくい。し
かし下降流が非常に大きいために、介在物が奥深くまで
巻き込まれる。そのために、浮上°除去がほとんどでき
ず、鋳片内に非常に多くの介在物が残る。When there is only one discharge port at the bottom of the conventional nozzle (FIG. 5), the upward flow is small, so fluctuations in the melt level are unlikely to occur. However, the downward flow is so large that inclusions are entangled deep inside. As a result, it is almost impossible to remove the float, and a large number of inclusions remain in the slab.

そこで、１つだけの吐出口を浸漬ノズルに設け、さらに
、鋳型壁面に衝突する際の吐出流の流速を小さくするた
めに、鋳型の幅方向中心よりずらして浸漬ノズルを設置
し、吐出口を鋳型幅中心方向に向ける。Therefore, in order to provide the immersion nozzle with only one discharge port and to reduce the flow velocity of the discharge flow when it collides with the mold wall, the immersion nozzle is installed offset from the center in the width direction of the mold, and the discharge port is Point toward the center of the mold width.

浸漬ノズルの吐出口を鋳型の幅方向の中心に向けること
により、ノズルからの吐出流は一度鋳型短辺面の凝固シ
ェルに衝突する。この衝突する時の流速が大きくならな
いように、すなわち、溶鋼吐出時の流速を小さくするた
めに、吐出口の断面積は大きくしておく。また、浸漬ノ
ズルの吐出口の吐出角度は、上向きにすると上昇流れが
大きくなり、湯面変動か大きくなるため、下向きにする
。By directing the discharge port of the submerged nozzle toward the widthwise center of the mold, the discharge flow from the nozzle once collides with the solidified shell on the short side of the mold. The cross-sectional area of the discharge port is made large so that the flow velocity at the time of collision does not become large, that is, in order to reduce the flow velocity at the time of discharging molten steel. Moreover, the discharge angle of the discharge port of the immersion nozzle is set downward because if it is set upward, the upward flow will be large and the fluctuation of the melt level will be large.

その角度は、鋳込速度や鋳型の大きさ２こよって異なる
が、鋳込速度が大きくなるにつれ、大きくするのが好ま
しい。The angle differs depending on the casting speed and the size of the mold, but it is preferable to increase it as the casting speed increases.

浸漬ノズルの吐出口と衝突流の当たる鋳型短辺面の距離
を大きく、つまり浸漬ノズルを吐出口がある方向とは反
対側の鋳型端部付近に設置することにより、鋳型短辺面
の凝固シェルへの衝突流を小さくできる。By increasing the distance between the discharge port of the immersion nozzle and the short side of the mold that is hit by the collision flow, that is, by installing the immersion nozzle near the end of the mold on the opposite side of the direction where the discharge port is located, the solidified shell on the short side of the mold can be Collision flow can be reduced.

以上のようにして、鋳型短辺面の凝固シェルに衝突する
溶鋼の流速を小さくできるので、衝突により生じた上昇
流や下降流は小さくなる。その結果、湯面変動は小さく
なり、パウダの巻込みは抑制され、介在物は奥深くまで
巻込まれることなく浮上して除去されるために、少なく
なる。さらに、吐出口が１つであるので、片流れは起ら
す、ノズル内側に酸化物等が付着して吐出流速が変化し
て湯面が変動しても、スライディングゲート等で給湯量
を制御することによって、吐出流速を一定に保ち、簡単
に湯面を安定させることかできる。As described above, the flow velocity of the molten steel that collides with the solidified shell on the short side of the mold can be reduced, so that the upward flow and downward flow caused by the collision are reduced. As a result, fluctuations in the hot water level are reduced, powder entrainment is suppressed, and inclusions are removed by floating to the surface without being entangled deeply, thereby reducing the number of inclusions. Furthermore, since there is only one discharge port, one-sided flow will occur, and even if oxides, etc. adhere to the inside of the nozzle and the discharge flow rate changes and the hot water level fluctuates, the amount of hot water supplied can be controlled using a sliding gate, etc. By doing so, the discharge flow rate can be kept constant and the hot water level can be easily stabilized.

（へ）実施例 本発明の鋼の連続鋳造における給湯方法の実施例につい
て、第１図を参照して説明する。(f) Example An example of the method for supplying hot water in continuous casting of steel according to the present invention will be described with reference to FIG.

本発明の方法は高速で連続鋳造する場合、浸漬ノズル３
の鋳型幅方向の側面の１方向にのみ吐出口３ａを設け、
ノズル３を吐出口３ａとは反対側の鋳型の短辺面付近に
浸漬して、溶鋼槽から鋳型１へ溶鋼を給湯する。浸漬ノ
ズル３は、Ａ　Ｉ　２０ｓ　、　Ｓ　ｌ　０２　、　Ｚ
　ｒ　０２　、　ＣａＯ等の酸化物や黒鉛、ＳｉＣ等で
つくられる。In the method of the present invention, when performing continuous casting at high speed, the immersion nozzle 3
A discharge port 3a is provided only in one direction on the side surface in the width direction of the mold,
Molten steel is supplied from the molten steel tank to the mold 1 by immersing the nozzle 3 near the short side of the mold on the side opposite to the discharge port 3a. The immersion nozzle 3 is A I 20s, S l 02, Z
It is made from oxides such as r 02 , CaO, graphite, SiC, etc.

吐出口３ａは、吐出流速が大きくなりすぎないように、
その断面積は大きくする。具体的には、少なくとも浸漬
ノズル３の内断面積よりも大きくする必要がある。吐出
口断面積をあまり大きくしても、吐出口３ａの上部の方
は溶鋼が流出しないため、ノズル内断面積の１．５〜２
．５倍の大きさが好ましい。The discharge port 3a is designed to prevent the discharge flow rate from becoming too large.
Its cross-sectional area should be large. Specifically, it needs to be larger than at least the internal cross-sectional area of the immersion nozzle 3. Even if the cross-sectional area of the discharge port is made too large, the molten steel will not flow out from the upper part of the discharge port 3a, so it is
．． Five times the size is preferred.

大きい断面積からできるだけ均等な吐出流を得るために
、第２図に示すように、断面積の異なる複数の吐出口３
ａ、３ｂ、３ｃ、をノズルの１方向に設けても良い。In order to obtain as uniform a discharge flow as possible from a large cross-sectional area, a plurality of discharge ports 3 with different cross-sectional areas are provided as shown in FIG.
a, 3b, and 3c may be provided in one direction of the nozzle.

吐出口３ａの吐出角度が小さいと、上下の向きにかかわ
らず、鋳型短辺面の凝固シェル５に衝突した後の上昇流
２ｂが大きくなり、湯面変動が大きくなる。このため、
パウダの巻込みも多くなる。When the discharge angle of the discharge port 3a is small, the upward flow 2b after colliding with the solidified shell 5 on the short side of the mold becomes large regardless of the vertical direction, and the fluctuation in the melt level becomes large. For this reason,
There will also be more powder involved.

逆に、吐出角度が下向きで大きすぎると、介在物が巻き
込まれる深さ（侵入深さ）が大きくなるために、介在物
が浮上除去されにくくなり、鋳片に多くの介在物が残る
。このため、吐出角度は注意して決める必要があり、鋳
込速度や鋳型の大きさによ、って適切な値を選択する必
要がある。実際には、吐出角度は下向きに１０〜５０６
が望ましい。On the other hand, if the discharge angle is downward and too large, the depth at which the inclusions are rolled up (penetration depth) becomes large, making it difficult for the inclusions to float and be removed, and many inclusions remain in the slab. Therefore, the discharge angle must be determined with care, and an appropriate value must be selected depending on the casting speed and the size of the mold. In reality, the discharge angle is 10 to 506 downwards.
is desirable.

この浸漬ノズル３は鋳型の幅方向中心よりノズルの吐出
口がある方向とは反対方向にずらせて浸漬する。ノズル
の吐出口と、鋳型短辺面の距離が大きいほど、鋳型短辺
面の凝固シェルへの衝突流の流速を小さくできるので、
ノズルの浸漬位置は、反吐出口側の鋳型の短辺面に近い
のが好ましい９ただし、短辺と浸漬ノズル３とがあまり
近いと、鋳型１に生成した凝固シェル５が浸漬ノズル３
と接触して凝固シェル５を破断させたりするため好まし
くない、そこで、鋳型短辺面より３０〜１００柑か望ま
しい、また、短辺からの最大離隔距離は鋳型長辺の約１
７４程度か好ましい、この距離かそれ以上になると、従
来のものとあまり変わりなくなるからである。The immersion nozzle 3 is immersed so as to be offset from the center in the width direction of the mold in a direction opposite to the direction in which the nozzle discharge port is located. The larger the distance between the nozzle outlet and the short side of the mold, the lower the velocity of the flow impinging on the solidified shell on the short side of the mold.
It is preferable that the immersion position of the nozzle be close to the short side of the mold on the side opposite to the discharge port 9 However, if the short side and the immersion nozzle 3 are too close, the solidified shell 5 generated on the mold 1 will be exposed to the immersion nozzle 3.
Therefore, it is preferable that the distance be 30 to 100 mm from the short side of the mold, and the maximum distance from the short side is about 1 of the long side of the mold.
A distance of about 74 is preferable, because if it becomes this distance or more, it will not be much different from the conventional one.

次に、本発明の方法の具体的実施例を示す、湾曲半径が
１０ｍの２ストランドを有する連続鋳造機で厚み１８０
間、幅１６００ｎｕｎのスラブを鋳造した。溶鋼は低炭
素アルミキルド８１ｉ４（Ｃ：　０．０５％Ｓ　１　：
　０．０１％、Ｍｎ：０．２２％、　Ｐ　：　０．０１
２％、Ｓ：０、００４％、　Ａ　１　：　０．０５２％
）である、鋳込速度は、３．３　ｆ！ｌ／ｌ１ｉｎであ
る。Next, a continuous casting machine having two strands with a radius of curvature of 10 m was used to cast a film with a thickness of 180 mm, showing a specific example of the method of the present invention.
During this period, a slab with a width of 1600 nm was cast. The molten steel is low carbon aluminum killed 81i4 (C: 0.05%S 1:
0.01%, Mn: 0.22%, P: 0.01
2%, S: 0.004%, A1: 0.052%
), the casting speed is 3.3 f! l/l1in.

第１ストランドでは第１図に示す。本発明法Ｇこより、
内径７５ｍｍのＡ　１２０　ｓ黒鉛製の浸漬ノズル３を
用いた。吐出口３ａの大きさは、７０　ｎｍ　ｘｌｌｏ
ｍｍの長方形とした。ノズル３は鋳型１の短辺面より５
０＋＋ｕｎ離して設置した・第２ストランドでは、比較
例として第６図に示す従来法で、内径７５ｍｍのＡ　１
２０　ｉ黒鉛製の２孔ノズルを用いて、鋳型の中心に設
置した。吐出口の大きさは６５■Ｘ６５１Ｍ＋である。The first strand is shown in FIG. From the present invention method G,
An immersion nozzle 3 made of A 120 s graphite with an inner diameter of 75 mm was used. The size of the discharge port 3a is 70 nm xllo
It was made into a rectangle of mm. The nozzle 3 is located at a distance of 5 from the short side of the mold 1.
For the second strand, which was installed 0++un apart, the conventional method shown in Figure 6 was used as a comparative example, and A 1 with an inner diameter of 75 mm was used.
A two-hole nozzle made of 20 i graphite was used and placed in the center of the mold. The size of the discharge port is 65cm x 651M+.

０ずれのストランドの場合でも吐出角度は４５°とした
。Even in the case of a strand with zero deviation, the discharge angle was set to 45°.

鋳込み中の鋳型内の湯面変動量は、過流式距離計を使っ
て鋳型の幅方向２箇所の位置を測定した。The amount of fluid level fluctuation in the mold during pouring was measured at two positions in the width direction of the mold using an overflow distance meter.

また、得られた鋳片については、その介在物量を調べた
。In addition, the amount of inclusions in the obtained slab was investigated.

鋳造中の湯面変動量を、第３図に示す、従来法の第２ス
トランドでは、片側の湯面変動量が非常に大きくなる。FIG. 3 shows the amount of variation in the level of the molten metal during casting. In the second strand of the conventional method, the amount of variation in the level of the molten metal on one side is extremely large.

これは、浸漬ノズルからの吐出流が片流れしたためと考
えられる。一方１、本発明法による第１ストランドでは
、いずれの湯面変動も小さく、安定していた。This is considered to be because the discharge flow from the immersion nozzle flowed in one direction. On the other hand, 1. In the first strand produced by the method of the present invention, all fluctuations in the level of the molten metal were small and stable.

得られた鋳片の介在物指数を第４図に示す、ここで介在
物指数とは、鋳片単位重量当りに発生する製品に悪影響
を及ぼす大きさの介在物個数である。The inclusion index of the obtained slab is shown in FIG. 4, where the inclusion index is the number of inclusions that are generated per unit weight of the slab and have a size that adversely affects the product.

第４図より、本発明法により介在物指数は大幅に低減し
ていることがわかる。これは湯面変動が小さくなり、パ
ウダの巻込みが減少したこと、および介在物が奥深くま
で浸入しなかったため浮上除去されやすかったことによ
る。From FIG. 4, it can be seen that the inclusion index is significantly reduced by the method of the present invention. This is due to the fact that the level fluctuations were smaller, reducing powder entrainment, and inclusions were easier to float and remove because they did not penetrate deeply.

（ト）効果 本発明の方法によれば、高速連続鋳造において、溶鋼湯
面の変動を抑制し、パウダの巻込みを低減することがで
きる。また、介在物の鋳片内部への侵入を防止すること
ができるため、清浄性の良好な鋳片を製造することがで
きる。(g) Effects According to the method of the present invention, fluctuations in the molten steel level can be suppressed and powder entrainment can be reduced in high-speed continuous casting. Moreover, since it is possible to prevent inclusions from entering the inside of the slab, a slab with good cleanliness can be manufactured.

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

第１図は本発明の詳細な説明図、第２図は本発明の方法
に用いる浸漬ノズルの別の実施例の説明図、第３図およ
び第４図は本発明の方法の実施結果を示すグラフ、第５
図および第６図は従来法の説明図。 １：鋳型　　　　　　　２：溶鋼 ３：浸漬ノズル　　　　４：バウダ ５：凝固シェル　　　　６：鋳片 ７：湯面　　　　　　　８ニレベル計 ３ａ：吐出口Fig. 1 is a detailed explanatory diagram of the present invention, Fig. 2 is an explanatory diagram of another embodiment of the submerged nozzle used in the method of the present invention, and Figs. 3 and 4 show the results of implementing the method of the present invention. Graph, 5th
FIG. 6 is an explanatory diagram of the conventional method. 1: Mold 2: Molten steel 3: Immersion nozzle 4: Bauder 5: Solidified shell 6: Slab 7: Molten metal surface 8 Two-level meter 3a: Discharge port

Claims (1)

【特許請求の範囲】[Claims] 鋼を連続的に鋳造するにさいして、溶鋼槽から鋳型へ溶
鋼を供給する浸漬ノズルにおいて、溶鋼の吐出口を一方
の側面にのみ設けた浸漬ノズルを、鋳型の幅方向にその
中心よりずらせて配置し、前記吐出口を該中心方向に向
けて鋳型内に溶鋼を供給することを特徴とした鋼の連続
鋳造における給湯方法。When continuously casting steel, in the immersion nozzle that supplies molten steel from the molten steel tank to the mold, the immersion nozzle, which has a molten steel discharge port on only one side, is shifted from the center in the width direction of the mold. A method for supplying hot water in continuous casting of steel, characterized in that molten steel is supplied into a mold with the discharge port directed toward the center of the mold.