JP3515762B2 - Immersion nozzle for continuous casting and continuous casting method - Google Patents
Immersion nozzle for continuous casting and continuous casting methodInfo
- Publication number
- JP3515762B2 JP3515762B2 JP2001045097A JP2001045097A JP3515762B2 JP 3515762 B2 JP3515762 B2 JP 3515762B2 JP 2001045097 A JP2001045097 A JP 2001045097A JP 2001045097 A JP2001045097 A JP 2001045097A JP 3515762 B2 JP3515762 B2 JP 3515762B2
- Authority
- JP
- Japan
- Prior art keywords
- nozzle
- continuous casting
- swirl
- flow
- discharge
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
- B22D41/50—Pouring-nozzles
- B22D41/507—Pouring-nozzles giving a rotating motion to the issuing molten metal
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、鋼の連続鋳造方法
において使用される、内部に捩り板型旋回羽根を設置し
てノズル内を流下する溶鋼に旋回流を付与する連続鋳造
用浸漬ノズル（以下、「旋回流ノズル」ともいう。）及
びこの旋回流ノズルを用いた連続鋳造方法に関するもの
である。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous casting immersion nozzle for use in a continuous casting method for steel, which is provided with a twisting plate type swirl vane inside and imparts a swirl flow to molten steel flowing down in the nozzle ( Hereinafter, it is also referred to as "swirl flow nozzle") and a continuous casting method using this swirl flow nozzle.
【０００２】[0002]
【従来の技術】浸漬ノズル内を流下する溶鋼に旋回流を
付与すると、底面に対向する２つの吐出孔を有する２孔
ノズルの場合には、遠心力により２つの吐出孔に溶鋼が
強制的に分配されて吐出するので、２つの吐出孔からの
吐出流量や吐出速度の変動が小さくなって吐出孔からの
吐出流の状態が安定し、鋳型内に不均等な流動（片流
れ）が生じ難くなる。2. Description of the Related Art When a swirl flow is applied to molten steel flowing down in an immersion nozzle, in the case of a two-hole nozzle having two discharge holes facing each other on the bottom surface, the molten steel is forced to the two discharge holes by centrifugal force. Since they are distributed and discharged, fluctuations in the discharge flow rate and discharge speed from the two discharge holes are reduced, the state of the discharge flow from the discharge holes is stabilized, and uneven flow (one-sided flow) in the mold is less likely to occur. .
【０００３】片流れは、鋳型内の溶鋼流速を著しく変動
させるので、鋳型内溶鋼流の停滞に伴って溶鋼流の凝固
シェル洗浄作用が低下し、非金属介在物や気泡が凝固シ
ェルに捕捉されやすくなったり、鋳型内における過大な
溶鋼流速が渦を発生させてモールドパウダーなどを鋳片
内に巻き込む原因となる。Since the one-way flow remarkably changes the molten steel flow velocity in the mold, the solidified shell cleaning action of the molten steel flow is reduced due to the stagnation of the molten steel flow in the mold, and nonmetallic inclusions and bubbles are easily trapped in the solidified shell. Or, an excessively high molten steel flow rate in the mold causes vortices to cause mold powder and the like to be caught in the slab.
【０００４】これら鋳型内流動の不均等（片流れ）に起
因する鋳片表面疵の低減には、旋回流ノズルの適用が有
効であると期待されている（例えば、ＣＡＭＰ−ＩＳＩ
Ｊ（１９９７），８０９）。It is expected that the application of a swirl flow nozzle will be effective in reducing the surface defects of the cast slab due to the non-uniformity of the flow in the mold (single flow) (for example, CAMP-ISI).
J (1997), 809).
【０００５】また、筒状ノズルの底部に１つの吐出孔を
有する単孔ノズルの場合に旋回流ノズルを適用すると、
遠心力により吐出流が広がりながら吐出するので、吐出
流速が低下し、吐出流が鋳片内に侵入する深さが低下す
るという、電磁ブレーキ的効果が得られる。When a swirl flow nozzle is applied to a single-hole nozzle having one discharge hole at the bottom of a cylindrical nozzle,
Since the discharge flow is discharged while being spread by the centrifugal force, the discharge flow velocity is reduced, and the depth of the discharge flow entering the slab is reduced, which is an electromagnetic braking effect.
【０００６】この効果により、鋳型内における介在物の
浮上が促進されたり（例えば、Ａ．Ｖａｔｅｒｌａｕｓ
ｅｔ ａｌ，３rdＣｏｎｆ．ｏｎ ＣＣ（１９９
８），７１５）、鋳型内湯面（メニスカス）温度が上昇
してモールドパウダーの溶融滓化が促進され鋳片肌が改
善されたり、鋳片内部の温度が低下して等軸晶が増え鋳
片中心部のポロシティ（引け巣）欠陥が減少したりする
といった効果が期待されている。Due to this effect, the floating of inclusions in the mold is promoted (for example, A. Vatterlaus).
et al, 3 rd Conf. on CC (199
8), 715), the temperature of the molten metal (meniscus) in the mold rises to promote the melting and melting of the mold powder to improve the slab surface, and the temperature inside the slab decreases to increase equiaxed crystals It is expected to have the effect of reducing the porosity (shrinkage cavity) defects in the central part.
【０００７】上述のような効果が期待されているにも関
わらず、旋回流ノズルが実用化された報告例は無い。そ
れは、実機において浸漬ノズル内に旋回流を形成する手
法が確立されていないからに他ならない。従来、浸漬ノ
ズル内を流下する溶鋼に旋回流を付与する実用的な方法
として、ＣＡＭＰ−ＩＳＩＪ（１９９７）、７５３や、
特開平１１−９０５９３号に記載されたように、捩り板
型の固定式旋回羽根をノズル内に設置する方法が知られ
ている。[0007] Despite the expectation of the above-mentioned effects, there are no reports of practical applications of swirl flow nozzles. That is because the method of forming a swirl flow in the immersion nozzle has not been established in the actual machine. Conventionally, as a practical method for imparting a swirling flow to molten steel flowing down in the immersion nozzle, CAMP-ISIJ (1997), 753,
As described in Japanese Patent Laid-Open No. 11-90593, there is known a method of installing a twisting plate type fixed swirl vane in a nozzle.
【０００８】[0008]
【発明が解決しようとする課題】しかしながら，これら
の開示例にはノズル内部に捩り板型旋回羽根を設置した
浸漬ノズルを実用化するに際し、要求される旋回羽根の
仕様・浸漬ノズルの形状を明記したものはなく、単なる
アイデアにとどまっていた。However, in these disclosed examples, the specification of the swirl vane and the shape of the dip nozzle are required when the immersion nozzle having the twisted plate swirl vane inside the nozzle is put to practical use. There was nothing I could do, it was just an idea.
【０００９】本発明は、かかる実情に鑑みてなされたも
のであり、ノズル内部に捩り板型旋回羽根を設置した旋
回流ノズルを実用化するに際し、要求される旋回羽根の
仕様や旋回流ノズルの形状を、各種実験やシミュレーシ
ョンを重ねて明らかにしたものである。The present invention has been made in view of the above circumstances, and when the swirl flow nozzle in which a twisted plate type swirl vane is installed inside the nozzle is put to practical use, the swirl vane specifications and swirl flow nozzle required The shape was clarified through repeated experiments and simulations.
【００１０】[0010]
【課題を解決するための手段】上記した目的を達成する
ために、本発明は、下記数式１に定義される旋回羽根捩
りピッチＰｃを０．８〜３．０、旋回羽根捩り角θを６
０〜１８０°、旋回羽根の外径（＝２Ｒ）を５０〜２５
０ｍｍ、旋回羽根の厚みを外径の５〜３０％とし、旋回
羽根下端と吐出孔との間において内径を絞り、その絞り
後の横断面積を下記数式２で定義される旋回羽根部流路
有効断面積Ｓｅの最小値の０．５〜１．８倍の範囲内に
設定すると共に、下記数式３で示したタンディッシュと
鋳型間の必要ヘッド予測値Ｈを０．３〜２．０（ｍ）の
範囲内におさめた旋回流ノズルを使用して連続鋳造する
こととしている。そして、このようにすることで、２孔
ノズルの場合には、鋳片表面疵を低減するという効果が
期待でき、また、単孔ノズルの場合には、鋳片肌が改善
されたり鋳片中心部のポロシティ（引け巣）欠陥が減少
するという効果が期待できる。In order to achieve the above object, the present invention provides a swirl vane twist pitch Pc defined by the following formula 1 of 0.8 to 3.0 and a swirl vane twist angle θ of 6:
0 to 180 °, the outer diameter of the rotating blade (= 2R) is 50 to 25
0 mm, the thickness of the swirl vane is 5 to 30% of the outer diameter, the inner diameter is narrowed between the lower end of the swirl vane and the discharge hole, and the cross-sectional area after the narrowing is effective for the swirl vane passage defined by the following mathematical formula 2. It is set within the range of 0.5 to 1.8 times the minimum value of the cross-sectional area Se, and the required head predicted value H between the tundish and the mold shown in the following formula 3 is 0.3 to 2.0 (m. ) It is decided to perform continuous casting using a swirl flow nozzle within the range. By doing so, in the case of a two-hole nozzle, an effect of reducing the slab surface flaw can be expected, and in the case of a single-hole nozzle, the slab surface can be improved or the slab center can be improved. The effect of reducing the porosity (shrinkage cavity) defects of the part can be expected.
【００１１】[0011]
【数１】Ｐｃ＝Ｌ・π／（２・Ｒ・θ） 但し、Ｌ：旋回羽根捩り部長さ（ｍｍ） Ｒ：旋回羽根半径（ｍｍ） θ：旋回羽根捩り角（ｒａｄ）[Equation 1] Pc = L · π / (2 · R · θ) However, L: swirl vane twisting part length (mm) R: Radius of swirl vane (mm) θ: Twisting blade twist angle (rad)
【００１２】[0012]
【数２】Ｓｅ（ｍｍ2 ）＝ｓｉｎ（ｔａｎ-1（２・Ｐｃ
・θ／π2 ））・Ｓ1
但し、Ｓ1 ：旋回羽根部横断面流路面積（ｍｍ2 ）[Equation 2] Se (mm 2 ) = sin (tan −1 (2 · Pc
・ Θ / π 2 )) ・ S 1 where S 1 is the cross-sectional area of the swirling blade section (mm 2 ).
【００１３】[0013]
【数３】Ｈ（ｍ）＝（５６０・Ｋ＋０．０６）・ＥＸＰ
（０．０２４・ＴＰ）
但し、ＴＰ：溶鋼スループット（ｋｇ／ｓｅｃ）
Ｋ：旋回速度定数（ｍｍ2 ）
〔＝（Ｄ1 ／Ｄ2 ）・｛π／（２・Ｐｃ・Ｓ1 ）｝〕
Ｄ1 ：旋回羽根部ノズル内径（ｍｍ）
Ｄ2 ：旋回羽根下端と吐出孔間における絞り後のノズル
内径（ｍｍ）[Equation 3] H (m) = (560 ・ K + 0.06) ・ EXP
(0.024 · TP) where TP: Molten steel throughput (kg / sec) K: Turning rate constant (mm 2 ) [= (D 1 / D 2 ) · {π / (2 · Pc · S 1 )}] D 1 : Swirling blade nozzle inner diameter (mm) D 2 : Nozzle inner diameter (mm) between the lower end of the swirl blade and the discharge hole
【００１４】[0014]
【発明の実施の形態】本発明者らは、旋回流ノズルの実
用化に際し、種々実験並びにシミュレーションを重ねた
結果、捩り板型旋回羽根の設計が不適切であると流動抵
抗が過大となって必要な溶鋼供給ができなくなる等の問
題点を見出し、これらの問題点を解消する手法としての
下記の本発明の完成に到ったのである。BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have conducted various experiments and simulations to put a swirl flow nozzle into practical use, and as a result, if the design of a twisted plate swirl vane is improper, the flow resistance becomes excessive. The inventors have found problems such as the inability to supply necessary molten steel, and have completed the present invention described below as a method for solving these problems.
【００１５】すなわち、本発明に係る第１の連続鋳造用
浸漬ノズルは、連続鋳造用タンディッシュ底部における
流量調整装置の下流側に取り付けられ、内部に捩り板型
旋回羽根を設置した浸漬ノズルであって、上記数式１に
定義される旋回羽根捩りピッチＰｃを０．８〜３．０、
旋回羽根捩り角θを６０〜１８０°、旋回羽根の外径
（＝２Ｒ）を５０〜２５０ｍｍ、旋回羽根の厚みを前記
旋回羽根の外径の５〜３０％とし、旋回羽根下端と吐出
孔との間において内径を絞り、その絞り後の横断面積を
上記数式２で定義される旋回羽根部流路有効断面積Ｓｅ
の最小値の０．５〜１．８倍の範囲内に設定すると共
に、上記数式３で示したタンディッシュと鋳型間の必要
ヘッド予測値Ｈを０．３〜２．０（ｍ）の範囲内におさ
めたものである。That is, the first continuous casting immersion nozzle according to the present invention is an immersion nozzle which is attached to the bottom of the continuous casting tundish downstream of the flow rate adjusting device and has a twisted plate type swirl blade installed therein. Then, the swirl vane twist pitch Pc defined in the above formula 1 is 0.8 to 3.0,
The swirl vane twist angle θ is 60 to 180 °, the swirl vane outer diameter (= 2R) is 50 to 250 mm, the swirl vane thickness is 5 to 30% of the outer diameter of the swirl vane, and the swirl vane lower end and the discharge hole are formed. The inner diameter of the swirling blade portion is narrowed between the two, and the cross-sectional area after the narrowing is defined by the swirl vane flow path effective cross-sectional area Se
Is set to a range of 0.5 to 1.8 times the minimum value of, and the required head predicted value H between the tundish and the mold shown in Equation 3 is in the range of 0.3 to 2.0 (m). It was stored inside.
【００１６】ところで、捩りピッチＰｃとは、捩り板が
１８０°捩られるのに直径の何倍の長さを要するかとい
う、捩りの強さを表す指標であり、その値が小さいほど
捩りは強くなるが、本発明に係る第１の連続鋳造用浸漬
ノズルにおいて、捩りピッチＰｃが０．８未満であると
捩りが強過ぎ、旋回羽根を通過する溶鋼の流動抵抗が過
大となって設計はもとより圧縮成型による旋回羽根の製
造も困難になる。一方、捩りピッチＰｃが３．０を越え
ると、捩りが弱すぎて十分な旋回流が得られなくなる。
そこで、本発明に係る第１の連続鋳造用浸漬ノズルで
は、数式１に定義される旋回羽根捩りピッチＰｃを０．
８〜３．０としている。なお、数式１における旋回羽根
半径が捩り羽根上端と下端で異なる場合には、平均値を
用いて算出すればよい。By the way, the twist pitch Pc is an index showing the strength of the twist, which is how many times the diameter is required to twist the twist plate by 180 °. The smaller the value, the stronger the twist. However, in the first continuous casting immersion nozzle according to the present invention, when the twist pitch Pc is less than 0.8, the twist is too strong, and the flow resistance of the molten steel passing through the swirl vanes becomes excessive, which is not only the design. It is also difficult to manufacture swirl vanes by compression molding. On the other hand, if the twist pitch Pc exceeds 3.0, the twist is too weak to obtain a sufficient swirling flow.
Therefore, in the first continuous casting immersion nozzle according to the present invention, the swirl vane twist pitch Pc defined by the mathematical formula 1 is set to 0.
It is set to 8 to 3.0. In addition, when the turning blade radius in the numerical formula 1 is different between the upper end and the lower end of the twisting blade, the average value may be used for the calculation.
【００１７】また、旋回羽根捩り角θとは、捩り板の捩
り量を、捩り板の直径と平行な面に投影して求めた角度
であるが、本発明に係る第１の連続鋳造用浸漬ノズルに
おいて、旋回羽根捩り角θが６０°未満であると、ノズ
ル内流路横断面に占める旋回羽根の占有面積が小さくな
り、均等な旋回流が得られなくなる。一方、旋回羽根捩
り角θが１８０°を越えた旋回羽根捩り角θを付与する
ことは、意味が無いばかりかいたずらに流動抵抗を増や
す原因となる。さらに、圧縮成型による旋回羽根の製造
も困難となる。そこで、本発明に係る第１の連続鋳造用
浸漬ノズルでは、旋回羽根捩り角θを６０〜１８０°と
している。The swirl vane twist angle θ is an angle obtained by projecting the twist amount of the twist plate on a plane parallel to the diameter of the twist plate, and is the first continuous casting dip according to the present invention. In the nozzle, when the swirl vane twist angle θ is less than 60 °, the area occupied by the swirl vanes in the cross section of the flow path in the nozzle becomes small, and a uniform swirl flow cannot be obtained. On the other hand, imparting a swirl vane twist angle θ in which the swirl vane twist angle θ exceeds 180 ° is not only meaningless but also causes an unreasonable increase in flow resistance. Further, it becomes difficult to manufacture the swirl vane by compression molding. Therefore, in the first continuous casting immersion nozzle according to the present invention, the swirl vane twist angle θ is set to 60 to 180 °.
【００１８】また、本発明に係る第１の連続鋳造用浸漬
ノズルにおいて、旋回羽根の外径（＝２Ｒ）が５０ｍｍ
未満であると、この旋回羽根によって所定の旋回流を付
与するためには、溶鋼流路が狭過ぎることになって溶鋼
や鋼中の非金属介在物の付着により容易に閉塞し、操業
性が悪化する。一方、外径が２５０ｍｍを越えると、浸
漬ノズル本体が巨大化してハンドリングが困難になるな
ど、操業が阻害される。そこで、本発明に係る第１の連
続鋳造用浸漬ノズルでは、旋回羽根の外径（＝２Ｒ）を
５０〜２５０ｍｍとしている。Further, in the first continuous casting dipping nozzle according to the present invention, the outer diameter (= 2R) of the swirling blade is 50 mm.
If it is less than this, the molten steel flow path becomes too narrow to give a predetermined swirling flow by the swirling vanes, and the molten steel and non-metallic inclusions in the steel are easily clogged and the operability is deteriorated. Getting worse. On the other hand, if the outer diameter exceeds 250 mm, the immersion nozzle body becomes huge and handling becomes difficult, and the operation is hindered. Therefore, in the first continuous casting immersion nozzle according to the present invention, the outer diameter (= 2R) of the swirling blade is set to 50 to 250 mm.
【００１９】また、本発明に係る第１の連続鋳造用浸漬
ノズルにおいて、旋回羽根の厚みが旋回羽根外径の５％
未満であると、構造体としての強度が不足し鋳込中に破
損する虞がある。また、旋回羽根外径の３０％を越える
厚みは、強度上は不要であるばかりか、いたずらに流動
抵抗を増す要因となる。そこで、本発明に係る第１の連
続鋳造用浸漬ノズルでは、旋回羽根の厚みを外径の５〜
３０％としている。構造上の強度が求められるのは、タ
ンディッシュからの溶鋼流にさらされる旋回羽根の上部
であるので、必要に応じて上記厚みの範囲内において上
部を厚く下部を薄く成形してもよい。Further, in the first continuous casting immersion nozzle according to the present invention, the thickness of the swirl blade is 5% of the outer diameter of the swirl blade.
If it is less than the above range, the strength of the structure is insufficient and there is a risk of damage during casting. A thickness of more than 30% of the outer diameter of the swirl vane is not only necessary in terms of strength, but also becomes a factor to unnecessarily increase the flow resistance. Therefore, in the first continuous casting immersion nozzle according to the present invention, the thickness of the swirl vane is set to 5 to the outer diameter.
30%. Since structural strength is required for the upper part of the swirl vane exposed to the molten steel flow from the tundish, the upper part may be thickened and the lower part may be thinned within the above-mentioned thickness range, if necessary.
【００２０】また、内部に捩り板型旋回羽根を設置した
旋回流ノズル１において、図１に示したように、旋回羽
根２の下端と吐出孔１ａとの間において内径を絞ること
は、下記のように旋回羽根２によって形成される旋回流
を均一化する上で必要であり、その際、絞り後の断面積
は、数式２で定義される旋回羽根部流路有効断面積Ｓｅ
の最小値の０．５〜１．８倍とするのがよい。Further, in the swirl flow nozzle 1 having a twisted plate type swirl vane installed therein, as shown in FIG. 1, the inner diameter is narrowed between the lower end of the swirl vane 2 and the discharge hole 1a. It is necessary to make the swirl flow formed by the swirl vanes 2 uniform as described above, and in this case, the cross-sectional area after the throttling is the swirl vane channel effective cross-sectional area Se defined by Formula 2.
It is preferable to set it to 0.5 to 1.8 times the minimum value of.
【００２１】旋回羽根部の流路面積は、横断面で見る
と、旋回羽根部のノズル孔内径で規定される円断面から
略長方形状の旋回羽根専有面積を除いた旋回羽根部横断
面流路面積Ｓ1 （ｍｍ2 ）であるが、旋回羽根内の溶鋼
は捩りピッチＰｃに対応した角度θを持って流れるの
で、本発明では、旋回羽根部流路有効断面積Ｓｅをこの
流動角を考慮して数式２のように定義した。When viewed in cross section, the flow passage area of the swirl vane is a cross section of the swirl vane which is obtained by removing a substantially rectangular swirl vane exclusive area from the circular cross section defined by the inner diameter of the nozzle hole of the swirl vane. Although the area is S 1 (mm 2 ), the molten steel in the swirl vane flows at an angle θ corresponding to the twist pitch Pc. Therefore, in the present invention, the swirl vane channel effective sectional area Se is taken into consideration in this flow angle. And defined as in Equation 2.
【００２２】ところで、旋回羽根２の下端から流出した
溶鋼は、旋回羽根２（捩り板）の両側で形成された２つ
の捩り流に分かれて流下する。従って、旋回羽根２の下
端と吐出孔１ａとの間において、図１に示したように、
ノズル孔の内径を絞ることは、この２つの捩り流を混ぜ
合わせ、均一な旋回流を得る効果を有する。By the way, the molten steel flowing out from the lower end of the swirl vane 2 is divided into two twist flows formed on both sides of the swirl vane 2 (twist plate) and flows down. Therefore, between the lower end of the swirl vane 2 and the discharge hole 1a, as shown in FIG.
Narrowing the inner diameter of the nozzle hole has the effect of mixing the two twisted flows and obtaining a uniform swirl flow.
【００２３】しかしながら、この絞り後の断面積が、数
式２で定義される旋回羽根部流路有効断面積Ｓｅの最小
値の０．５倍未満となるような過剰な絞りは不要である
ばかりか、いたずらに流動抵抗を増やす要因となる。反
対に、絞り後の断面積が、数式２で定義される旋回羽根
部流路有効断面積Ｓｅの最小値の１．８倍を越えると、
上記絞り効果が不十分となる。そこで、本発明に係る第
１の連続鋳造用浸漬ノズルでは、絞り後の横断面積を数
式２で定義される旋回羽根部流路有効断面積Ｓｅの最小
値の０．５〜１．８倍の範囲内に設定している。However, it is not necessary to provide an excessive throttling such that the cross-sectional area after the throttling is less than 0.5 times the minimum value of the swirl vane channel effective cross-sectional area Se defined by the mathematical formula 2. , It becomes a factor to unnecessarily increase the flow resistance. On the contrary, when the cross-sectional area after the restriction exceeds 1.8 times the minimum value of the swirl vane channel effective cross-sectional area Se defined by Equation 2,
The above throttling effect becomes insufficient. Therefore, in the first continuous casting immersion nozzle according to the present invention, the cross-sectional area after drawing is 0.5 to 1.8 times the minimum value of the swirl vane channel effective cross-sectional area Se defined by Formula 2. It is set within the range.
【００２４】この２つの捩り流を混ぜ合わせ均一な旋回
流を得るには、旋回羽根の下端以降、吐出孔までの距離
を長くとることも有効であるので、操業上無理のない範
囲内において旋回羽根を吐出孔から離して設置すると、
さらに均一な旋回流が得られることになる。In order to obtain a uniform swirl flow by mixing these two twisted flows, it is effective to increase the distance from the lower end of the swirl blade to the discharge hole, so swirl within a range that is not unreasonable in operation. If you install the blade away from the discharge hole,
Further, a uniform swirling flow can be obtained.
【００２５】また、本発明者らは、内部に捩り板型旋回
羽根を設置した旋回流ノズルが、その捩り板型旋回羽根
の影響によりどの程度流動抵抗を増すかについて、水モ
デル等の実験並びに解析を重ねた。その結果、旋回羽根
仕様と溶鋼スループットとの関係においてタンディッシ
ュと鋳型間の必要ヘッドを予測する数式３の導出に到っ
た。Further, the inventors of the present invention have conducted experiments such as a water model on how much the swirl flow nozzle having the twisted plate type swirl vane inside increases the flow resistance due to the influence of the twisted plate swirl vane. The analysis was repeated. As a result, Formula 3 was derived to predict the required head between the tundish and the mold in the relationship between the swirl blade specifications and the molten steel throughput.
【００２６】ここで、旋回速度定数Ｋ（ｍｍ2 ）とは、
旋回流外周部のノズル横断面投影旋回速度成分をＷ（ｍ
ｍ／ｓｅｃ）、ノズル内溶鋼流量をＱ（ｍｍ3 ／ｓｅ
ｃ）としたとき、Ｗ＝Ｋ・Ｑを満たす定数であり、溶鋼
流量に対して得られる旋回流の強さを表す指標である。Here, the turning speed constant K (mm 2 ) is
The nozzle cross-section projection swirl velocity component at the outer periphery of the swirl flow is expressed as W (m
m / sec), the flow rate of molten steel in the nozzle is Q (mm 3 / se
c) is a constant that satisfies W = K · Q and is an index showing the strength of the swirling flow obtained with respect to the molten steel flow rate.
【００２７】この旋回速度定数Ｋは溶鋼を非圧縮性流体
と仮定した上で、質量保存則と角運動量保存則を用い
て、以下の数式４〜１０のように導出した。先ず、ある
ピッチの旋回羽根により形成される旋回流を、図２に示
すように、ねじのピッチ及び捩り角と推進距離との関係
に置き換えてモデル化した。旋回流のノズル横断面投影
旋回速度成分Ｗは羽根外周部における流速を代表旋回流
速として用いた。This swirl rate constant K was derived as in the following equations 4 to 10 by using the law of conservation of mass and the law of conservation of angular momentum on the assumption that molten steel is an incompressible fluid. First, as shown in FIG. 2, the swirl flow formed by the swirl vanes with a certain pitch was modeled by replacing it with the relationship between the pitch and twist angle of the screw and the propulsion distance. For the nozzle cross-section projected swirl velocity component W of the swirl flow, the flow velocity at the outer peripheral portion of the blade was used as the representative swirl flow velocity.
【００２８】ノズル横断面投影旋回速度成分Ｗは、ノズ
ル横断面投影鉛直速度成分をＶ、旋回羽根の半径をＲ、
旋回羽根の捩り角をθ、推進距離すなわち旋回羽根捩り
部長さをＬとした場合、図２より、下記の数式４で表わ
すことができる。The nozzle cross-section projected swirl velocity component W is the nozzle cross-section projected vertical velocity component V, the swirl vane radius is R,
When the twisting angle of the swirl vane is θ and the propulsion distance, that is, the length of the swirl vane twisting portion is L, it can be expressed by the following formula 4 from FIG.
【００２９】[0029]
【数４】Ｗ＝Ｖ・Ｒ・θ／Ｌ[Equation 4] W = VR / θ / L
【００３０】一方、旋回流ノズルの捩りピッチＰｃはＬ
／Ｄ＝Ｌ／２Ｒであることから、これを変形するとＲ／
Ｌ＝１／２Ｐｃとなる。そして、これと、旋回羽根の捩
り角θ＝π（１８０°）を上記した数式４に代入する
と、ノズル横断面投影旋回速度成分Ｗは、下記の数式５
で求めることができる。On the other hand, the twist pitch Pc of the swirling flow nozzle is L
Since / D = L / 2R, if this is transformed into R /
L = 1 / 2Pc. Then, by substituting this and the twist angle θ = π (180 °) of the swirl vane into the above-mentioned formula 4, the nozzle cross-section projected swirl velocity component W is expressed by the following formula 5
Can be found at.
【００３１】[0031]
【数５】Ｗ＝（Ｖ・π）／（２・Ｐｃ）[Equation 5] W = (V · π) / (2 · Pc)
【００３２】また、図３に示したような旋回流ノズル１
において、旋回羽根２の下端と吐出孔１ａ間における絞
り後のノズル孔の内径Ｄ2 （ｍｍ）部分における旋回速
度定数Ｋは、上記したように下記の数式６で表わされ、
この絞り後のノズル孔の内径Ｄ2 部分における旋回流速
Ｗ2 は、角運動量保存則より下記の数式７で表わすこと
ができる。A swirl flow nozzle 1 as shown in FIG.
In the above, the swirl velocity constant K in the inner diameter D 2 (mm) portion of the nozzle hole after the throttling between the lower end of the swirl vane 2 and the discharge hole 1a is expressed by the following mathematical formula 6,
The swirling flow velocity W 2 in the inner diameter D 2 portion of the nozzle hole after the throttling can be expressed by the following formula 7 according to the law of conservation of angular momentum.
【００３３】[0033]
【数６】Ｋ＝Ｗ2 ／Ｑ[Equation 6] K = W 2 / Q
【００３４】[0034]
【数７】Ｗ2 ＝Ｗ1 ・（Ｄ1 ／Ｄ2 ）[Formula 7] W 2 = W 1 · (D 1 / D 2 )
【００３５】また、旋回羽根内における流動に上記した
数式５を適用した場合、下記の数式８となる。When the above-mentioned formula 5 is applied to the flow in the swirl vane, the following formula 8 is obtained.
【００３６】[0036]
【数８】Ｗ1 ＝（Ｖ1 ・π）／（２・Ｐｃ）[Formula 8] W 1 = (V 1 · π) / (2 · Pc)
【００３７】質量保存則より旋回羽根部におけるノズル
横断面投影鉛直速度成分Ｖ1 は、下記数式９で表すこと
ができることから、上記した数式６に数式７〜９を代入
すると、旋回速度定数Ｋは下記の数式１０で表わすこと
ができる。From the law of conservation of mass, the projected vertical velocity component V 1 of the nozzle cross-section in the swirl vane portion can be expressed by the following formula 9, so that when the formulas 7 to 9 are substituted into the above formula 6, the swirl velocity constant K becomes It can be expressed by the following Equation 10.
【００３８】[0038]
【数９】Ｖ1 ＝Ｑ／｛π（Ｄ1 ／２）2 −Ａ｝ 但し、Ａ：旋回羽根の占有断面積（横断面）Equation 9] V 1 = Q / {π ( D 1/2) 2 -A} where, A: occupied cross-sectional area (cross section) of the swirl vane
【００３９】[0039]
【数１０】Ｋ＝π（Ｄ1 ／Ｄ2 ）／〔２・｛π（Ｄ1 ／
２）2 −Ａ｝・Ｐｃ〕[Equation 10] K = π (D 1 / D 2 ) / [2 · {π (D 1 /
2) 2- A} · Pc]
【００４０】このようにして求めた旋回速度定数Ｋは、
質量保存則と角運動量保存則から自ずと導出されるもの
であり本質的に新規性はないが、本発明者らは、旋回に
要するエネルギー損失が流動抵抗の主体であると考えた
ので、旋回速度定数Ｋ並びに旋回流ノズル内を流下する
溶鋼のスループットＴＰ（単位時間当たりのノズル内通
鋼重量）をパラメータとすると、タンディッシュと鋳型
間の必要ヘッドを予測する実験式が得られるとの考えに
到り、解析の結果、上記した数式３を得た。The turning speed constant K thus obtained is
It is naturally derived from the law of conservation of mass and the law of conservation of angular momentum, and is essentially not novel, but the present inventors considered that the energy loss required for turning is the main cause of flow resistance, so the turning speed When the constant K and the throughput TP of molten steel flowing down in the swirl nozzle (the weight of steel in the nozzle per unit time) are used as parameters, an experimental formula for predicting the required head between the tundish and the mold can be obtained. As a result of the analysis, the above formula 3 was obtained.
【００４１】上記した数式３により求めたタンディッシ
ュと鋳型間の必要ヘッド予測値Ｈと、実測値とは図４の
ように良い相関を示した。従って、本発明に係る第１の
連続鋳造用浸漬ノズルでは、溶鋼を用いた実機試験の結
果から、数式３により求められるタンディッシュと鋳型
間の必要ヘッド予測値Ｈの適正範囲を０．３〜２．０ｍ
とした。As shown in FIG. 4, the required head predicted value H between the tundish and the mold obtained by the above-mentioned equation 3 and the actually measured value showed a good correlation. Therefore, in the first continuous casting immersion nozzle according to the present invention, from the result of the actual machine test using the molten steel, the appropriate range of the required head predicted value H between the tundish and the mold, which is obtained by Formula 3, is set to 0.3 to 2.0 m
And
【００４２】すなわち、溶鋼を用いた実機試験の結果に
よれば、タンディッシュと鋳型間の必要ヘッド予測値Ｈ
が０．３ｍ未満の場合には、旋回付与に必要なエネルギ
ーが不足し十分な旋回流が得られない。また、前記必要
ヘッド予測値Ｈが２．０ｍを越えると、タンディッシュ
内に溶鋼を目一杯溜めた場合にも、鋳型湯面とのヘッド
差が不足し、必要な溶鋼スループットＴＰを確保できな
いからである。なお、前記必要ヘッド予測値Ｈが過大な
条件下での鋳造は、一般的な連続鋳造機では困難であ
り、タンディッシュを嵩上げする等の大掛かりな連続鋳
造機の改造が必要となり、実用的とは言えない。That is, according to the result of the actual machine test using the molten steel, the required head predicted value H between the tundish and the mold is obtained.
Is less than 0.3 m, the energy required for imparting the swirl is insufficient and a sufficient swirl flow cannot be obtained. Further, if the required head predicted value H exceeds 2.0 m, even if the molten steel is fully filled in the tundish, the head difference from the mold molten metal surface is insufficient and the required molten steel throughput TP cannot be secured. Is. It should be noted that casting under the condition that the required head predicted value H is excessive is difficult with a general continuous casting machine, and a large-scale continuous casting machine remodeling such as raising the tundish is required, which is not practical. I can't say.
【００４３】上記した本発明に係る第１の連続鋳造用浸
漬ノズルにおいて、旋回羽根上端の長手方向がタンディ
ッシュ底部のスライディングゲートの摺動方向と平行と
なるように設置した場合には、流量調整装置がスライデ
ィングゲートである場合に、旋回羽根の両側に均等に溶
鋼を分配することができ、より均一な旋回流が形成され
る。これが本発明に係る第２の連続鋳造用浸漬ノズルで
ある。In the above-mentioned first immersion nozzle for continuous casting according to the present invention, when it is installed so that the longitudinal direction of the upper end of the swirl blade is parallel to the sliding direction of the sliding gate at the bottom of the tundish, the flow rate is adjusted. When the device is a sliding gate, the molten steel can be evenly distributed on both sides of the swirl vanes, and a more uniform swirl flow is formed. This is the second continuous casting immersion nozzle according to the present invention.
【００４４】溶鋼流は、タンディッシュ底部の流量調整
装置、例えばスライディングゲート４ａを通過する際
に、溶鋼下降流速分布が偏り易くなる。一方、図５に示
したように、旋回流ノズル１の旋回羽根２の上流側にお
いてノズル孔１ｂの内径を縮減する絞り部３を設けた場
合には、絞り部３の流動抵抗が旋回流ノズル横断面内の
溶鋼下降流速分布を均一化する作用を有することから、
旋回羽根２の両側にさらに均等に溶鋼を分配することが
でき、旋回流の均一性が高まる。When the molten steel flow passes through the flow rate adjusting device at the bottom of the tundish, for example, the sliding gate 4a, the molten steel descending flow velocity distribution is likely to be biased. On the other hand, as shown in FIG. 5, when the throttle portion 3 for reducing the inner diameter of the nozzle hole 1b is provided on the upstream side of the swirl vanes 2 of the swirl nozzle 1, the flow resistance of the throttle portion 3 causes the swirl nozzle to flow. Since it has the effect of making the molten steel descending flow velocity distribution in the cross section uniform,
Molten steel can be evenly distributed to both sides of the swirl vanes 2, and the uniformity of swirl flow is enhanced.
【００４５】しかしながら、本発明者らの実験によれ
ば、絞り部を設ける位置が旋回羽根の上端から２００ｍ
ｍを越えた上流側では、絞りの下降流速分布均一化効果
が減少する傾向にあった。また、絞りによる断面積縮減
率が１０％未満であると、十分な溶鋼下降流速分布の均
一化作用が得られない。反対に、断面積縮減率が３５％
を越えると、絞りによる流動抵抗が過大になるという弊
害が生じる。そこで、旋回羽根の上流側におけるノズル
孔内径の絞り部は、旋回羽根の上端から２００ｍｍ以内
の上流側において、１０〜３５％の範囲で縮減すること
にした。これが本発明に係る第３の連続鋳造用浸漬ノズ
ルである。However, according to the experiments conducted by the present inventors, the position where the diaphragm portion is provided is 200 m from the upper end of the rotating blade.
On the upstream side beyond m, there was a tendency that the effect of uniformizing the downward flow velocity distribution of the throttle was reduced. Further, if the cross-sectional area reduction rate due to the reduction is less than 10%, a sufficient uniformizing effect of the molten steel descending flow velocity distribution cannot be obtained. On the contrary, the cross-sectional area reduction rate is 35%
If it exceeds, the adverse effect of excessive flow resistance due to the restriction occurs. Therefore, it is decided that the throttle portion of the inner diameter of the nozzle hole on the upstream side of the swirl vane is reduced in the range of 10 to 35% on the upstream side within 200 mm from the upper end of the swirl vane. This is the third continuous casting immersion nozzle according to the present invention.
【００４６】上述のように適正に設計した本発明に係る
連続鋳造用浸漬ノズルの底部近傍に対向する２つの吐出
孔を穿って矩形断面鋳型内に注湯する場合、旋回流の影
響により、溶鋼が旋回方向に振れて吐出することにな
る。When pouring into the rectangular cross-section mold by forming two discharge holes facing each other in the vicinity of the bottom of the immersion nozzle for continuous casting according to the present invention properly designed as described above, the molten steel is affected by the swirling flow. Is shaken in the turning direction and discharged.
【００４７】本発明者らは、通常の吐出孔を有する旋回
流ノズルを用いて吐出方向の振れの影響を調査した結
果、本来、鋳型短辺５ａを向いて吐出するべき流れが鋳
型長辺５ｂに向いて図６に矢印で示したように吐出する
と、鋳型長辺５ｂへの衝突時に著しい流速減衰が生じ、
湯面における溶鋼流速が大きく低下することを知見し
た。As a result of investigating the influence of the fluctuation in the discharge direction by using a swirl flow nozzle having a normal discharge hole, the present inventors found that the flow originally to be discharged toward the mold short side 5a is the mold long side 5b. When discharged toward the mold as shown by the arrow in FIG. 6, significant flow velocity attenuation occurs at the time of collision with the long side 5b of the mold,
It was found that the molten steel flow velocity on the molten metal surface was significantly reduced.
【００４８】そして、本発明者らのさらなる実験によれ
ば、湯面における溶鋼流速の低下は、溶鋼流の凝固シェ
ル洗浄作用を損ない、凝固シェルヘの気泡や非金属介在
物の捕捉を助長する結果、鋳片の表面品質を劣化させる
が、この旋回流に起因する吐出方向の振れによる悪影響
は、以下のようにすることで、払拭されることを知見し
た。According to a further experiment conducted by the present inventors, a decrease in the molten steel flow velocity on the molten metal surface impairs the solidified shell cleaning action of the molten steel flow and promotes trapping of bubbles and non-metallic inclusions in the solidified shell. However, it has been found that the surface quality of the slab is deteriorated, but the adverse effect of the deflection in the ejection direction due to the swirling flow is wiped off by the following.
【００４９】すなわち、底部近傍に対向する２つの吐出
孔を有した上記した本発明に係る第１〜３の連続鋳造用
浸漬ノズルにおいて、タンディッシュ底部の流量調整装
置の下流側に設置した際、２つの吐出孔からの吐出流が
矩形断面鋳型の長辺と平行に吐出するように、図７に示
すように、前記２つの吐出孔１ａを鋳型長辺５ｂと平行
な線から反旋回方向に２〜１０°振った状態となるよう
に開設したり、或いは、本発明に係る第１〜３の連続鋳
造用浸漬ノズルを、２つの吐出孔からの吐出流が矩形断
面鋳型の長辺と平行に吐出するように、前記２つの吐出
孔が鋳型長辺と平行な線から反旋回方向に２〜１０°振
った状態となるように設置して鋳造するのである。これ
が本発明に係る第４の連続鋳造用浸漬ノズル、及び、本
発明に係る第１の連続鋳造方法である。That is, in the above-mentioned first to third immersion nozzles for continuous casting according to the present invention which have two discharge holes facing each other near the bottom, when they are installed on the tundish bottom on the downstream side of the flow rate adjusting device, As shown in FIG. 7, the two discharge holes 1a are directed in a direction opposite to the swirl direction from a line parallel to the mold long side 5b so that the discharge flows from the two discharge holes are discharged parallel to the long side of the rectangular cross-section mold. It is opened so as to be in a state of being swung by 2 to 10 °, or the first to third immersion nozzles for continuous casting according to the present invention have discharge flows from two discharge holes parallel to the long sides of the rectangular cross-section mold. So that the two discharge holes are swung in a direction opposite to the swirl direction by 2 to 10 ° from a line parallel to the long side of the mold. This is the fourth continuous casting immersion nozzle according to the present invention and the first continuous casting method according to the present invention.
【００５０】この吐出流の振れ角は、旋回速度や吐出孔
形状、ノズル肉厚（吐出孔壁の厚み）等の影響を受けて
変動するので、ノズルの振り角は吐出溶鋼の角度を見な
がら調整することが望ましい。本発明者らの実験におい
ては、吐出流が２〜１０°の範囲を超えて振れることは
なかった。なお、吐出孔側壁角度が一定でない場合（例
えば、末広がりの吐出孔）の吐出孔振れ角は、側壁角度
平均値に対して定義するものとする。The deflection angle of the discharge flow fluctuates under the influence of the swirling speed, the shape of the discharge hole, the wall thickness of the nozzle (the thickness of the wall of the discharge hole), etc. Therefore, the swing angle of the nozzle can be determined by observing the angle of the molten molten steel. It is desirable to adjust. In the experiments conducted by the present inventors, the discharge flow did not fluctuate beyond the range of 2 to 10 °. It should be noted that the ejection hole deflection angle when the ejection hole sidewall angle is not constant (for example, a divergent ejection hole) is defined with respect to the average sidewall angle.
【００５１】本発明者らは、底部近傍に対向する２つの
吐出孔を穿った旋回流ノズルを実機適用した場合の、吐
出孔周辺への非金属介在物の付着状況を、吐出孔開孔状
況を変えて調査した。その結果、吐出孔１ａの幅をノズ
ル孔１ｂの内径よりも小さい矩形状となした吐出孔側壁
の一方を、図８（ａ）（ｂ）に示したように、ノズル孔
１ｂの内壁に沿う旋回流の旋回接線方向に倣って開孔
し、対向する２つの吐出孔１ａがノズル中心軸に対し点
対称となるように開孔した場合に、吐出孔周辺への非金
属介在物付着が少ないことを見出した。これが本発明に
係る第５の連続鋳造用浸漬ノズルである。この本発明に
係る第５の連続鋳造用浸漬ノズルによれば、吐出孔周辺
の流動淀み域が小さくなって介在物の付着軽減に効果を
奏する。The inventors of the present invention have shown the state of non-metallic inclusions adhering to the periphery of the discharge hole when the swirl flow nozzle having two discharge holes facing each other in the vicinity of the bottom is actually used. I changed it and investigated. As a result, one of the side walls of the discharge hole 1a, in which the width of the discharge hole 1a is smaller than the inner diameter of the nozzle hole 1b, extends along the inner wall of the nozzle hole 1b, as shown in FIGS. When the holes are opened along the swirl tangential direction of the swirl flow and the two opposing discharge holes 1a are formed so as to be point-symmetric with respect to the central axis of the nozzle, non-metallic inclusions are less attached to the periphery of the discharge holes. I found that. This is the fifth continuous casting immersion nozzle according to the present invention. According to the fifth continuous casting immersion nozzle according to the present invention, the flow stagnation area around the discharge hole is reduced, and the adhesion of inclusions is reduced.
【００５２】旋回流ノズルは、旋回流に作用する遠心力
により２つの吐出孔に強制的に吐出流を分配するので、
対称位置にある各吐出孔からの吐出流量が均等になる利
点を有する。しかしながら、鋳込の進行とともに旋回羽
根に非金属介在物が付着して旋回流が不均等になると、
図９（ａ）に示したように、各吐出孔１ａからの吐出流
量に差異が生じる場合がある。Since the swirl flow nozzle forcibly distributes the discharge flow to the two discharge holes by the centrifugal force acting on the swirl flow,
This has the advantage that the discharge flow rates from the respective discharge holes located at symmetrical positions become uniform. However, if non-metallic inclusions adhere to the swirl vanes and the swirl flow becomes uneven as the casting progresses,
As shown in FIG. 9A, the discharge flow rate from each discharge hole 1a may differ.
【００５３】本発明者らの実験によれば、このような場
合にも、ノズル底部に図９（ｂ）に示したような深さが
５〜３０ｍｍの滝壷状凹部１ｃを有していると、比較的
均等な吐出流量分配を維持できることが判明した。これ
は、滝壷状凹部が偏った流れを再分配する作用を有する
ためである。According to the experiments conducted by the present inventors, even in such a case, it is found that the bottom of the nozzle has a waterhole-shaped recess 1c having a depth of 5 to 30 mm as shown in FIG. 9B. It was found that a relatively even distribution of the discharge flow rate can be maintained. This is because the waterfall-shaped recess has a function of redistributing a biased flow.
【００５４】この際、吐出孔からの吐出角度は、下向き
１５°以上、４０°以下に調整することが望ましい。本
発明者らは、水モデル実験により鋳型内流動を注意深く
観察した結果、旋回流ノズル１の吐出孔１ａからの吐出
角度が下向き１５°より浅いと、図１０の右半分に示し
たように、白抜き矢印で示した吐出流と斜線網かけ矢印
で示した鋳型短辺５ａからの反転流とが干渉し大きな湯
面変動を生じることを見出した。湯面変動の増大は凝固
シェル６ヘの非金属介在物付着やモールドパウダー巻き
込み等の鋳片表面欠陥を発生させる。At this time, it is desirable that the discharge angle from the discharge hole is adjusted to 15 ° or more and 40 ° or less downward. As a result of careful observation of the flow in the mold by the water model experiment, the present inventors found that if the discharge angle from the discharge hole 1a of the swirl nozzle 1 is shallower than 15 ° downward, as shown in the right half of FIG. It was found that the discharge flow indicated by the white arrow and the reversal flow from the mold short side 5a indicated by the shaded arrow interfere with each other to cause a large fluctuation in the molten metal surface. An increase in the fluctuation of the molten metal surface causes a slab surface defect such as non-metallic inclusions adhering to the solidified shell 6 or inclusion of mold powder.
【００５５】一方、旋回流ノズルの吐出孔からの吐出角
度が下向き４０°より深すぎる場合には、各吐出孔から
の吐出流量が均等になる利点を有する旋回流ノズルを適
用しているにもかかわらず、鋳型内流動に自励振動的片
流れが発生し、流れが偏った側の湯面が大きく変動する
ことを見出した。On the other hand, when the discharge angle from the discharge hole of the swirl flow nozzle is deeper than 40 ° downward, the swirl flow nozzle having the advantage of equalizing the discharge flow rate from each discharge hole is also applied. Nevertheless, it was found that self-excited oscillatory one-sided flow occurs in the flow in the mold, and the molten metal surface on the side where the flow is biased greatly fluctuates.
【００５６】これらの知見により、本発明者らは、上記
した適正な吐出角度の範囲を定めるに到ったのである。
旋回流ノズルの吐出孔からの吐出角度が本発明の範囲内
であれば、図１０の左半分に示したように、白抜き矢印
で示した吐出流と斜面網かけ矢印で示した鋳型短辺５ａ
からの反転流との干渉が少なく、湯面変動に大きな影響
を与えない。本発明者らの水モデル実験によれば、最も
望ましい吐出孔からの吐出角度は下向き２０°以上、３
０°以下であった。Based on these findings, the inventors of the present invention have come to determine the above-mentioned appropriate range of the ejection angle.
If the discharge angle from the discharge hole of the swirl flow nozzle is within the range of the present invention, as shown in the left half of FIG. 10, the discharge flow indicated by the white arrow and the mold short side indicated by the slanted hatched arrow 5a
There is little interference with the reversal flow from, and it does not affect the fluctuation of the molten metal level significantly. According to the water model experiment of the present inventors, the most desirable discharge angle from the discharge hole is 20 ° or more downward and 3
It was 0 ° or less.
【００５７】上記した吐出角度は、旋回流の捩りピッチ
により変化するが、吐出孔壁角度や吐出孔の大きさ、吐
出流に含まれる不活性ガス量を調整することにより適正
な範囲に制御することが可能である。各因子の影響は、
一般的に捩りピッチが大きい場合や、吐出孔の上下壁が
下向きの大きな角度である場合や、吐出孔が大きい場合
や、吐出流に含まれる不活性ガス量が少ない場合に下向
きの吐出角度が大きくなる傾向にある。The above-mentioned discharge angle varies depending on the twist pitch of the swirling flow, but is controlled within an appropriate range by adjusting the discharge hole wall angle, the size of the discharge hole, and the amount of inert gas contained in the discharge flow. It is possible. The influence of each factor is
Generally, when the twist pitch is large, when the upper and lower walls of the discharge hole have a large downward angle, when the discharge hole is large, or when the amount of inert gas contained in the discharge flow is small, the downward discharge angle is Tends to grow.
【００５８】本発明に係る連続鋳造用浸漬ノズルにあっ
ては、鋳型内湯面（メニスカス）の平均流速は２０ｃｍ
／ｓｅｃ以上、６０ｃｍ／ｓｅｃ以下が望ましい。２０
ｃｍ／ｓｅｃよりも遅いと溶鋼流の凝固シェル洗浄作用
を損ない、凝固シェルヘの気泡や非金属介在物の捕捉を
助長し、鋳片表面品質悪化を招くからである。また、鋳
型内湯面（メニスカス）の平均流速が６０ｃｍ／ｓｅｃ
よりも過大であると、湯面に渦が発生してモールドパウ
ダーを巻き込むからである。In the immersion nozzle for continuous casting according to the present invention, the average flow velocity on the molten metal surface (meniscus) in the mold is 20 cm.
/ Sec or more and 60 cm / sec or less is desirable. 20
This is because if it is slower than cm / sec, the solidified shell cleaning action of the molten steel flow is impaired, the bubbles and non-metal inclusions are trapped in the solidified shell, and the surface quality of the cast piece is deteriorated. Also, the average flow velocity on the molten metal surface (meniscus) in the mold is 60 cm / sec.
If it is too large, a vortex will be generated on the surface of the molten metal and the mold powder will be involved.
【００５９】鋳型内湯面（メニスカス）の平均流速は、
鋳造速度、溶鋼スループット、鋳型形状等により変化す
るが、吐出孔面積の増減に応じて減少、増加する特性を
活かして適正範囲に調整することが可能である。溶鋼吐
出角度を適正値に保った時、各因子の影響は、鋳造速度
や溶鋼スループットが大きい場合や、鋳型断面積が小さ
い場合や、吐出孔面積が小さい場合にメニスカス流速が
大きくなる傾向にある。The average flow velocity on the molten metal surface (meniscus) in the mold is
Although it changes depending on the casting speed, the molten steel throughput, the shape of the mold, etc., it can be adjusted to an appropriate range by taking advantage of the characteristic that it decreases or increases as the area of the discharge hole increases or decreases. When the molten steel discharge angle is maintained at an appropriate value, the influence of each factor tends to increase the meniscus flow velocity when the casting speed and molten steel throughput are large, the mold cross-sectional area is small, and the discharge hole area is small. .
【００６０】これらノズル底部への滝壷状凹部の設置、
溶鋼吐出角度の適正化、鋳型内湯面（メニスカス）平均
流速の調整を同時に行うと、安定して適正な流動を保つ
ことができる。これが本発明に係る第６の連続鋳造用浸
漬ノズルである。Installation of a waterhole-shaped recess at the bottom of these nozzles,
If the molten steel discharge angle is optimized and the molten metal surface (meniscus) average flow velocity in the mold is adjusted at the same time, stable and proper flow can be maintained. This is the sixth continuous casting immersion nozzle according to the present invention.
【００６１】本発明者らは、ノズル側壁に複数の吐出孔
を穿つ場合に、吐出孔上壁の形状と吐出孔上部への非金
属介在物付着状況との関係を調査した。その結果、図１
１に示すように、吐出孔１ａの上壁１ａａを半径Ｒ1 が
４０ｍｍ以上、１８０ｍｍ以下の円弧状となし、ノズル
孔１ｂの内壁から吐出孔１ａの上壁１ａａに向って拡管
状断面を有するように成形した場合に、吐出孔上部への
非金属介在物の付着が少ないことを見出した。これが本
発明に係る第７の連続鋳造用浸漬ノズルである。The present inventors investigated the relationship between the shape of the upper wall of the discharge hole and the state of non-metallic inclusions adhering to the upper portion of the discharge hole when a plurality of discharge holes were formed in the side wall of the nozzle. As a result,
As shown in FIG. 1, the upper wall 1aa of the discharge hole 1a is formed in an arc shape having a radius R1 of 40 mm or more and 180 mm or less, and has an expanded tubular cross section from the inner wall of the nozzle hole 1b toward the upper wall 1aa of the discharge hole 1a. It was found that the non-metallic inclusions adhered little to the upper portion of the discharge hole when molded into a sheet. This is the seventh continuous casting immersion nozzle according to the present invention.
【００６２】このような吐出孔上壁形状にすると、旋回
しつつ流下する溶鋼流が遠心力により拡管状の吐出孔上
壁に沿って吐出するようになるので、吐出孔上壁部の流
動淀み域が小さくなり、介在物付着が軽減される。但
し、吐出孔上壁の半径Ｒ1 が４０ｍｍよりも小さい場合
には、曲率が急であるために吐出流の剥離が生じやす
く、介在物付着軽減効果が損なわれる。また、１８０ｍ
ｍよりも大きい場合には、吐出孔上壁部のノズル肉厚が
薄くなり、ノズルの耐久性が低下する。そこで、本発明
に係る第７の連続鋳造用浸漬ノズルでは上記半径Ｒ1 を
４０ｍｍ以上、１８０ｍｍ以下としたのである。With such a discharge hole upper wall shape, the molten steel flow flowing down while swirling is discharged along the expanded pipe discharge hole upper wall by centrifugal force, so that the flow stagnation of the discharge hole upper wall portion occurs. The area becomes smaller, and the adhesion of inclusions is reduced. However, when the radius R1 of the upper wall of the discharge hole is smaller than 40 mm, the discharge flow is likely to be separated due to the steep curvature, and the effect of reducing the adhesion of inclusions is impaired. Also, 180m
When it is larger than m, the nozzle wall thickness of the upper wall portion of the discharge hole becomes thin, and the durability of the nozzle deteriorates. Therefore, in the seventh continuous casting immersion nozzle according to the present invention, the radius R1 is set to 40 mm or more and 180 mm or less.
【００６３】旋回流ノズルを用いて矩形断面鋳型に給湯
する場合、鋳型幅中央から何れかの短辺側に偏って設置
されると、鋳型内の流動が不均等となり、旋回流ノズル
のメリットを十分に享受することができない。本発明者
らの実験によると、図１２に示すように、旋回流ノズル
１が鋳型幅中央から５０ｍｍ以上偏って設置されると、
図１３に示したように、鋳片の表面品質の悪化が顕著で
あった。このことから、旋回流ノズルは鋳型幅中央から
５０ｍｍ以内に設置することが望まれる。本発明者らの
実験によると、鋳型幅中央から２０ｍｍ以内に設置した
場合には、更に好ましい結果が得られた。これが本発明
に係る第２の連続鋳造方法である。When hot water is supplied to a rectangular cross-section mold by using a swirl flow nozzle, if it is installed deviating from the center of the mold width to any one of the short sides, the flow in the mold becomes uneven, and the advantage of the swirl flow nozzle is obtained. I cannot fully enjoy it. According to the experiments by the present inventors, as shown in FIG. 12, when the swirl flow nozzle 1 is installed with a deviation of 50 mm or more from the center of the mold width,
As shown in FIG. 13, the deterioration of the surface quality of the slab was remarkable. From this, it is desired that the swirl flow nozzle be installed within 50 mm from the center of the mold width. According to the experiments conducted by the present inventors, more preferable results were obtained when the mold was installed within 20 mm from the center of the mold width. This is the second continuous casting method according to the present invention.
【００６４】次に、底の無い単孔の吐出孔を形成した連
続鋳造用浸漬ノズルについて、説明する。図１４に示し
たように、底の無い単孔の吐出孔１ａのノズル孔１ｂの
内壁との連続部分を円弧状となし、ノズル孔１ｂの内壁
から吐出孔１ａに向って拡管状断面を有するように成形
すると、旋回しつつ流下する溶鋼が遠心力により横に広
がりつつ吐出するので、図１５に示したような通常の単
孔ノズル７を採用した場合のように、吐出流により非金
属介在物が鋳片の深くへ持ち込まれたり、鋳型内湯面
（メニスカス）への溶鋼供給が不十分で温度が低下し気
泡や非金属介在物の浮上分離が妨げられるといった問題
が解消される。また、吐出孔近傍での溶鋼流の淀み域が
小さくなるので、吐出孔への介在物付着も減少する。な
お、図１４中の４ｂはタンディッシュ底部の流量調整装
置であるストッパーを示す。Next, a continuous casting immersion nozzle having a single bottomed discharge hole will be described. As shown in FIG. 14, the continuous portion of the single-bottomed discharge hole 1a with the inner wall of the nozzle hole 1b is formed in an arc shape, and has an expanded tubular cross section from the inner wall of the nozzle hole 1b toward the discharge hole 1a. In this case, since the molten steel flowing down while swirling is discharged while being spread laterally by the centrifugal force, the non-metallic intervening by the discharge flow as in the case of adopting the normal single-hole nozzle 7 as shown in FIG. It is possible to solve the problems that the object is brought deep into the slab and that the molten steel is insufficiently supplied to the molten metal surface (meniscus) in the mold to lower the temperature and hinder the floating separation of bubbles and non-metallic inclusions. Further, since the stagnation area of the molten steel flow in the vicinity of the discharge hole becomes small, the adhesion of inclusions to the discharge hole also decreases. In addition, 4b in FIG. 14 shows a stopper which is a flow rate adjusting device at the bottom of the tundish.
【００６５】しかしながら、前記したノズル孔内壁との
連続部分の円弧状の半径Ｒ2 が４０ｍｍよりも小さい場
合には、曲率が急であるために吐出流の剥離に伴う淀み
域が生じやすく、介在物付着軽減効果が損なわれる。一
方、半径Ｒ2 が１８０ｍｍよりも大きい場合には、吐出
孔上壁郡のノズル肉厚が薄くなり、ノズルの耐久性が低
下する。そこで、本発明の連続鋳造用浸漬ノズルでは、
上記本発明に係る底の無い単孔の吐出孔を有した第１〜
３の連続鋳造用浸漬ノズルにおいて、前記した半径Ｒ2
を４０ｍｍ以上、１８０ｍｍ以下とした。これが本発明
に係る第８の連続鋳造用浸漬ノズルである。However, when the arc-shaped radius R2 of the continuous portion with the inner wall of the nozzle hole is smaller than 40 mm, the stagnation region easily occurs due to the separation of the discharge flow because the curvature is steep, and the inclusions are present. The adhesion reducing effect is impaired. On the other hand, when the radius R2 is larger than 180 mm, the nozzle wall thickness of the upper wall of the discharge hole is thin, and the durability of the nozzle is reduced. Therefore, in the continuous casting immersion nozzle of the present invention,
The first to the third embodiment having a single-hole discharge hole without a bottom according to the present invention
In the continuous casting dipping nozzle No. 3, the above-mentioned radius R2
Was 40 mm or more and 180 mm or less. This is the eighth continuous casting immersion nozzle according to the present invention.
【００６６】ところで、スラブの連続鋳造に水平循環流
を形成する鋳型内電磁攪拌を適用する場合に問題となる
のは、２孔ノズルからの吐出流によリ鋳型内に形成され
る流れ（反転流）９と、電磁攪拌が形成する流れ１０と
が干渉する点である。この干渉により図１６に示すよう
な淀み部位８が発生し、局部的に図１６に矢印で示した
溶鋼流の凝固シェル洗浄作用が低下することになって、
鋳片の表面品質が悪化するという問題が発生する。By the way, when applying electromagnetic stirring in a mold for forming a horizontal circulating flow to continuous casting of a slab, the problem is that the flow formed in the mold by the discharge flow from the two-hole nozzle (reversal). Flow) 9 and the flow 10 formed by the electromagnetic stirring interfere with each other. Due to this interference, a stagnation portion 8 as shown in FIG. 16 is generated, and the solidified shell cleaning action of the molten steel flow indicated by the arrow in FIG. 16 is locally reduced,
There is a problem that the surface quality of the slab deteriorates.
【００６７】しかしながら、上記した本発明に係る第８
の連続鋳造用浸漬ノズルを用いると共に、旋回方向と同
方向の水平循環流を形成するよう鋳型内を電磁攪拌する
と、上述のような流れの干渉問題が生じることがないの
で、鋳型内電磁攪拌の効果を十分に享受できることにな
る。これが本発明に係る第３の連続鋳造方法である。な
お、同等の効果を有する対策として、通常の単孔ノズル
を用いて鋳型内電磁攪拌と鋳型下部に電磁ブレーキを併
用することも考えられるが、設備費が高く実現性に乏し
い。However, the eighth aspect of the present invention described above.
While using the continuous casting immersion nozzle of, electromagnetic stirring in the mold to form a horizontal circulation flow in the same direction as the swirling direction, since the flow interference problem as described above does not occur, the electromagnetic stirring of the mold You will be able to fully enjoy the effect. This is the third continuous casting method according to the present invention. As a measure having the same effect, it is conceivable to use an ordinary single-hole nozzle for electromagnetic stirring in the mold and an electromagnetic brake at the bottom of the mold, but the equipment cost is high and the feasibility is poor.
【００６８】一方、丸ビレットの連続鋳造に上記した本
発明に係る第８の連続鋳造用浸漬ノズルを用いると、旋
回しつつ流下する溶鋼が遠心力により横に広がりつつ吐
出されるので、鋳型内湯面（メニスカス）への上昇流が
生じて湯面温度が上昇し、気泡や非金属介在物の浮上分
離を促進されるという効果が得られる。On the other hand, when the eighth continuous casting dipping nozzle according to the present invention is used for continuous casting of round billets, the molten steel flowing down while swirling is discharged while being spread laterally by the centrifugal force. An effect is obtained in which an upward flow to the surface (meniscus) occurs, the temperature of the molten metal surface rises, and the floating separation of bubbles and non-metallic inclusions is promoted.
【００６９】ところが、本発明者らによる実験の結果、
本発明に係る第８の連続鋳造用浸漬ノズルに鋳型内電磁
攪拌を併用した場合には、図１７に示すように、上述の
効果が縮減ないしは消滅することが判明した。なお、図
１７中の○印は鋳型径がφ３１０ｍｍの場合、●印は同
じくφ２２５ｍｍの場合の結果であり、順方向とはノズ
ル内旋回と同方向を、逆方向とはノズル内旋回と逆方向
を示す。However, as a result of the experiment by the present inventors,
When the eighth continuous casting immersion nozzle according to the present invention is used together with in-mold electromagnetic stirring, it has been found that the above-mentioned effects are reduced or eliminated as shown in FIG. The circles in FIG. 17 are the results when the mold diameter is φ310 mm, and the circles are the same when φ225 mm. The forward direction is the same direction as the in-nozzle swirl, and the reverse direction is the in-nozzle swirl direction. Indicates.
【００７０】すなわち、丸ビレットの連続鋳造に本発明
に係る第８の連続鋳造用浸漬ノズルを用いる場合には、
電磁攪拌を実施しないことが望ましい。これが本発明に
係る第４の連続鋳造方法である。That is, when the eighth continuous casting dipping nozzle according to the present invention is used for continuous casting of round billets,
It is desirable not to carry out magnetic stirring. This is the fourth continuous casting method according to the present invention.
【００７１】[0071]
【実施例】以下、本発明の効果を確認するために行なっ
た実験結果に基づいて説明する。下記表１および表２に
本発明の実施例と比較例の条件及びその実験結果を示
す。EXAMPLES The following description will be given based on the results of experiments conducted to confirm the effects of the present invention. Tables 1 and 2 below show the conditions of Examples and Comparative Examples of the present invention and the experimental results thereof.
【００７２】[0072]
【表１】 [Table 1]
【００７３】[0073]
【表２】 [Table 2]
【００７４】実施例Ａは、請求項１〜４、６〜９を満た
す本発明例である。実施例Ａでは、旋回羽根上流側に適
正な絞りが設けられ、かつ、旋回羽根上端の向き、旋回
羽根形状や旋回羽根下の絞りが適正であるので、操業し
易く、均一で必要十分な旋回流が形成された。また、旋
回羽根の強度は十分に確保され、旋回羽根部における非
金属介在物による閉塞も軽微であった。加えて吐出孔形
状、振り角、開孔方法、ノズル設置位置が適正であるの
で、鋳型内湯面の変動が小さく、適切な流速の安定した
流れが生じ、優れた鋳片表面品質が得られた。また、吐
出孔への非金属介在物付着（詰まり）も軽微であった。Example A is an example of the present invention which satisfies claims 1 to 4 and 6 to 9. In Example A, since a proper diaphragm is provided on the upstream side of the swirl blade, and the orientation of the upper end of the swirl blade, the shape of the swirl blade, and the diaphragm under the swirl blade are proper, the operation is easy, and the swirl is uniform and necessary and sufficient. A stream was formed. In addition, the strength of the swirl vane was sufficiently secured, and the clogging of the swirl vane portion by non-metallic inclusions was also slight. In addition, since the discharge hole shape, swing angle, opening method, and nozzle installation position are appropriate, the fluctuation of the molten metal level in the mold was small, a stable flow with an appropriate flow rate was generated, and excellent slab surface quality was obtained. . Further, non-metallic inclusions (clogging) on the discharge holes were also slight.
【００７５】実施例Ｂは、請求項１、２、４、７を満た
す本発明例である。実施例Ｂでは、旋回羽根上端の向
き、旋回羽根形状や旋回羽根下の絞りが適正であるの
で、操業し易く、均一な旋回流が形成された。実施例Ａ
に比べるとタンディッシュと鋳型間の必要ヘッド予測値
Ｈが小さいので旋回はやや弱いものの、十分な旋回流が
得られた。また、旋回羽根の強度は十分に確保されてい
る。旋回羽根部における非金属介在物による閉塞も軽微
であった。加えて吐出孔形状、振り角、開孔方法が適正
であるので、鋳型内湯面では必要とされる流速が安定し
て確保できている。吐出孔は側壁が旋回接線方向に沿う
開孔方法ではなく、吐出孔上壁形状も拡管状ではないの
で、ある程度吐出孔への非金属介在物付着（詰まり）が
見られたが、操業に支障を来たすほどではなかった。実
施例Ｂでは、設備上の制約によりノズルを鋳型幅方向中
央からややずらして設置したが、鋳片表面品質は良好で
あった。Example B is an example of the present invention satisfying claims 1, 2, 4, and 7. In Example B, the orientation of the upper end of the swirl vane, the shape of the swirl vane, and the diaphragm under the swirl vane were appropriate, so that the operation was easy and a uniform swirl flow was formed. Example A
The required head predicted value H between the tundish and the mold was smaller than that of Example 1, so that the swirling was slightly weak, but a sufficient swirling flow was obtained. Further, the strength of the swirl vane is sufficiently secured. The blockage due to non-metallic inclusions in the swirl vane was also slight. In addition, since the shape of the discharge hole, the swing angle, and the opening method are appropriate, the required flow velocity can be stably secured on the molten metal surface in the mold. Since the discharge hole is not an opening method in which the side wall is along the tangential direction of the swirl and the shape of the discharge hole upper wall is not expanded, some adhesion (clogging) of non-metallic inclusions to the discharge hole was observed, but this hindered operation. It wasn't enough to come. In Example B, the nozzle was placed slightly offset from the center in the width direction of the mold due to equipment restrictions, but the slab surface quality was good.
【００７６】実施例Ｃは、請求項１、２、１０、１２を
満たす本発明例である。実施例Ｃでは、旋回羽根上端の
向き、旋回羽根形状や旋回羽根下の絞りが適正であるの
で、操業し易く、均一な旋回流が形成された。また、旋
回羽根の強度は十分に確保されている。旋回羽根部にお
ける非金属介在物による閉塞も軽微であった。実施例Ｃ
では、単孔の吐出孔に適正な拡管状曲率を与えたので、
溶鋼流の淀み域が小さく、吐出孔への非金属介在物付着
は軽微であった。丸ビレットの鋳造に際し、鋳型内電磁
攪拌（水平回転）は実施していないので、吐出流は遠心
力により十分に広がり、また、鋳型内湯面温度を上昇さ
せたので、気泡や介在物の浮上分離が促進され、優れた
表面品質の鋳片が得られた。Example C is an example of the present invention satisfying claims 1, 2, 10, and 12. In Example C, the orientation of the upper end of the swirl vane, the shape of the swirl vane, and the diaphragm under the swirl vane were appropriate, so that the operation was easy and a uniform swirl flow was formed. Further, the strength of the swirl vane is sufficiently secured. The blockage due to non-metallic inclusions in the swirl vane was also slight. Example C
Then, since the proper expansive curvature was given to the single hole discharge hole,
The stagnation area of the molten steel flow was small, and the non-metallic inclusions adhered to the discharge holes were slight. When casting round billets, electromagnetic stirring (horizontal rotation) in the mold was not performed, so the discharge flow was sufficiently spread by the centrifugal force, and the molten metal surface temperature inside the mold was raised, so that air bubbles and inclusions floated and separated. Was promoted and a slab with excellent surface quality was obtained.
【００７７】実施例Ｄは、請求項１、１０、１１を満た
す本発明例である。実施例Ｄでは、旋回羽根形状や旋回
羽根下の絞りが適正であるので、操業し易く、均一な旋
回流が形成された。また、旋回羽根の強度は十分に確保
されている。旋回羽根部における非金属介在物による閉
塞も軽微であった。実施例Ｄでは、単孔の吐出孔に適正
な拡管状曲率を与えたので、溶鋼流の淀み域が小さく、
吐出孔への非金属介在物付着は軽微であった。加えて単
孔の旋回流ノズルと鋳型内電磁攪拌（水平回転）とを組
み合わせてスラブを鋳造したので、円滑かつ安定した鋳
型内湯面（メニスカス）流動が得られ、表面品質は極め
て良好であった。Example D is an example of the present invention satisfying claims 1, 10 and 11. In Example D, the swirl vane shape and the diaphragm under the swirl vane were appropriate, so that the swirl vane was easy to operate and a uniform swirl flow was formed. Further, the strength of the swirl vane is sufficiently secured. The blockage due to non-metallic inclusions in the swirl vane was also slight. In Example D, since the single-hole discharge hole was provided with an appropriate expanded tubular curvature, the stagnation area of the molten steel flow was small,
Adhesion of non-metallic inclusions to the discharge holes was slight. In addition, since a slab was cast by combining a single-hole swirl flow nozzle and electromagnetic stirring (horizontal rotation) in the mold, a smooth and stable molten metal (meniscus) flow in the mold was obtained, and the surface quality was extremely good. .
【００７８】実施例Ｅは、請求項１、３、７、８、９を
満たす本発明例である。実施例Ｅでは、旋回羽根上流側
に適正な絞りが設けられ、かつ、旋回羽根上端の向き、
旋回羽根形状や旋回羽根下の絞りが適正であるので、操
業し易く、均一で必要十分な旋回流が形成された。ま
た、旋回羽根の強度は十分に確保されている。旋回羽根
部における非金属介在物による閉塞も軽微であった。実
施例Ｅではノズル振り角は与えていないので、吐出流が
長辺に衝突し流速が低下する傾向にあったが、吐出孔を
実施例Ａ或いは実施例Ｂなどに比べて小さめに調整する
ことにより、吐出速度を速めてこれをカバーし、加え
て、吐出孔上下壁の形状、ノズル設置位置を適正化する
ことにより、鋳型内湯面の変動が小さく、適切な流速の
安定した流れが形成され、良好な鋳片表面品質が得られ
た。吐出孔は、側壁が旋回接線方向に沿う開孔方法では
ないので、若干の非金属介在物付着（詰まり）が見られ
たが、大きな問題とはならなかった。Example E is an example of the present invention satisfying claims 1, 3, 7, 8, and 9. In Example E, a proper diaphragm is provided on the upstream side of the swirl blade, and the direction of the upper end of the swirl blade is
Since the swirl vane shape and the diaphragm under the swirl vane are proper, it is easy to operate, and a uniform and necessary swirl flow is formed. Further, the strength of the swirl vane is sufficiently secured. The blockage due to non-metallic inclusions in the swirl vane was also slight. In Example E, since the nozzle swing angle was not given, the discharge flow tended to collide with the long side and the flow velocity tended to decrease, but the discharge hole should be adjusted smaller than in Example A or Example B. By increasing the discharge speed to cover it, and by optimizing the shape of the upper and lower walls of the discharge hole and the nozzle installation position, the fluctuation of the molten metal level in the mold is small and a stable flow with an appropriate flow velocity is formed. Good slab surface quality was obtained. Since the discharge hole is not formed by the method in which the side wall is along the tangential direction of rotation, some non-metallic inclusion adhesion (clogging) was observed, but it was not a serious problem.
【００７９】実施例Ｆは、請求項１、２、６、８、９を
満たす本発明例である。実施例Ｆでは、旋回羽根上端の
向き、旋回羽根形状や旋回羽根下の絞りが適正であるの
で、操業し易く、均一で必要十分な旋回流が形成され
た。また、旋回羽根の強度は十分に確保されている。旋
回羽根部における非金属介在物による閉塞も軽微であっ
た。ノズル振り角は与えていないが鋳片厚が４１０ｍｍ
と厚いので、吐出流の長辺への衝突は無視できる程度に
小さく影響が無かった。また、鋳型内電磁攪拌（水平回
転）と２孔ノズルとを組み合わせたが、溶鋼スループッ
トが小さく吐出流が少ないため吐出流と電磁攪拌流との
干渉問題は生じなかった。吐出孔形状、吐出孔開孔方
法、ノズル設置位置が適正であったので、鋳型内湯面変
動は小さく、電磁攪拌との組み合わせで適切な流速の安
定した流れが得られ、良い表面品質の鋳片が得られた。
吐出孔上壁形状が拡管状ではないので、若干、吐出孔へ
の非金属介在物付着（詰まり）が見られたものの、問題
となるレベルではなかった。Example F is an example of the present invention which satisfies claims 1, 2, 6, 8, and 9. In Example F, since the orientation of the upper end of the swirl vane, the shape of the swirl vane, and the diaphragm under the swirl vane were appropriate, the operation was easy, and a uniform and necessary swirl flow was formed. Further, the strength of the swirl vane is sufficiently secured. The blockage due to non-metallic inclusions in the swirl vane was also slight. No swing angle is given, but the thickness of the cast piece is 410 mm
Since it is thick, the collision of the discharge flow on the long side is negligibly small and has no effect. Further, electromagnetic stirring in the mold (horizontal rotation) and a two-hole nozzle were combined, but since the molten steel throughput was small and the discharge flow was small, there was no problem of interference between the discharge flow and the electromagnetic stirring flow. Since the shape of the discharge hole, the method of opening the discharge hole, and the nozzle installation position were appropriate, the fluctuation of the molten metal level in the mold was small, and a stable flow with an appropriate flow rate was obtained in combination with electromagnetic stirring, and a slab with good surface quality was obtained. was gotten.
Since the shape of the upper wall of the discharge hole was not expanded, some adhesion (clogging) of non-metallic inclusions to the discharge hole was observed, but this was not a problematic level.
【００８０】上記した実施例に対して、比較例Ｇは、旋
回羽根の捩りピッチＰｃが過大でタンディッシュと鋳型
間の必要ヘッド予測値Ｈが小さいので、十分な旋回流が
得られなかった。また、旋回羽根の捩り角θが４５°と
小さく、旋回羽根下の絞りも不十分（Ｓ2 ／Ｓｅが１．
９と大きい）であり、スライディングゲートの摺動方向
と旋回羽根上端長手方向の向きが平行ではなく、さら
に、旋回羽根上流に絞りが無いことから、形成される旋
回流が不均一であった。また、旋回羽根厚みが過大で流
路を挟めているので、非金属介在物が詰まると旋回羽根
部が容易に閉塞した。加えて、ノズル振り角が付与され
ていないので吐出流が長辺に衝突し流速が低下する傾向
にあった。さらに、溶鋼吐出角度が４５°と過度に深い
ので、鋳型湯面（メニスカス）流速が１８ｃｍ／ｓｅｃ
と小さく、凝固シェル洗浄作用が不十分であった。溶鋼
吐出角度が過度に深いことは、鋳型内において溶鋼流の
片流れを生じる要因でもある。また、ノズル設置位置が
鋳型幅方向中心から７０ｍｍと大きくずれているので鋳
型内流動が不均等であった。従って、鋳造したスラブに
は、これら旋回流の不均一さや鋳型内流動の不安定さに
起因する鋳片表面疵が多く発生した。In the comparative example G, the twist pitch Pc of the swirl vanes was excessive and the required head predicted value H between the tundish and the mold was small in the comparative example G, so that a sufficient swirl flow was not obtained. Further, the twist angle θ of the swirl vanes is as small as 45 °, and the diaphragm under the swirl vanes is insufficient (S 2 / Se is 1.
9), the sliding direction of the sliding gate was not parallel to the longitudinal direction of the upper end of the swirl vane, and there was no restriction upstream of the swirl vane, so the swirl flow formed was non-uniform. In addition, since the swirl vanes have an excessively large thickness and sandwich the flow path, the swirl vanes were easily blocked when non-metallic inclusions were clogged. In addition, since the nozzle swing angle is not given, the discharge flow tends to collide with the long side and the flow velocity tends to decrease. Furthermore, since the molten steel discharge angle is 45 °, which is excessively deep, the mold surface temperature (meniscus) is 18 cm / sec.
And the coagulation shell cleaning action was insufficient. An excessively deep molten steel discharge angle is also a factor that causes a partial flow of the molten steel flow in the mold. Further, since the nozzle installation position was largely deviated from the center in the width direction of the mold by 70 mm, the flow in the mold was uneven. Therefore, in the cast slab, many slab surface flaws were generated due to the nonuniformity of the swirling flow and the instability of the flow in the mold.
【００８１】また、比較例Ｈは、旋回羽根部ノズル内径
（旋回羽根径）Ｄ1 が４０ｍｍと小さく、旋回羽根部の
詰まりが顕著に発生した。また、丸ビレットの鋳造に際
し、鋳型内電磁攪拌（水平回転）を併せて実施したの
で、吐出流が遠心力により広がり鋳型内湯面温度を上昇
させるという旋回流ノズルの作用が十分に発揮できず、
鋳片表面品質が悪化した。また、吐出孔の拡管曲率Ｒが
３０ｍｍと小さいので、急激な拡管形状となっており、
吐出流の淀み域が生じ吐出孔への介在物付着が見られ
た。In Comparative Example H, the swirl vane nozzle inner diameter (swirl vane diameter) D 1 was as small as 40 mm, and the swirl vane was significantly clogged. Further, when casting the round billet, since electromagnetic stirring (horizontal rotation) in the mold was also carried out, the action of the swirling flow nozzle that the discharge flow spreads by centrifugal force and raises the molten metal surface temperature in the mold cannot be fully exerted,
The slab surface quality deteriorated. Further, since the pipe expansion curvature R of the discharge hole is as small as 30 mm, the pipe has a sharp pipe expansion shape.
A stagnation area of the discharge flow was generated and inclusions were observed to be attached to the discharge holes.
【００８２】なお、本発明は上記した実施例に限らない
ことは勿論であり、上記した実施例以外であっても、上
記した実施例に付加した或いは削減した構成の作用効果
が付加されたり、削減されたりするだけであることは言
うまでもない。It is needless to say that the present invention is not limited to the above-described embodiments, and the effects of the configurations added to or reduced from the above-mentioned embodiments are added to other than the above-mentioned embodiments. Needless to say, it will only be reduced.
【００８３】[0083]
【発明の効果】以上説明したように、本発明は上記した
実施例や比較例からも明らかなように、以下のような旋
回流ノズルに期待される効果を享受することができる。
すなわち、底面に対向する２つの吐出孔を有する２孔ノ
ズルの場合には、遠心力により２つの吐出孔に溶鋼が強
制的に分配され吐出するので、２つの吐出孔からの吐出
流量や吐出速度の変動が小さく安定しており、鋳型内に
不均等な流動（片流れ）が生じ難く、鋳型内流動の不均
等（片流れ）に起因する鋳片表面疵を低減する効果が期
待できる。As described above, the present invention can enjoy the effects expected of the following swirl flow nozzles, as is clear from the above-mentioned examples and comparative examples.
That is, in the case of a two-hole nozzle having two discharge holes facing each other on the bottom surface, the molten steel is forcibly distributed and discharged to the two discharge holes by the centrifugal force, so that the discharge flow rate and discharge speed from the two discharge holes are high. Is small and stable, uneven flow (single flow) is unlikely to occur in the mold, and an effect of reducing slab surface defects due to uneven flow in mold (single flow) can be expected.
【００８４】また、筒状ノズルの底部に１つの吐出孔を
有する単孔ノズルの場合には、旋回流ノズルを適用する
と、遠心力により吐出流が広がりながら吐出するので、
吐出流速が低下し、吐出流が鋳片内に侵入する深さが低
下するという電磁ブレーキ的効果により、鋳型内におけ
る介在物の浮上が促進されたり、鋳型内湯面（メニスカ
ス）温度が上昇してモールドパウダーの溶融滓化が促進
され鋳片肌が改善されたり、鋳片内部の温度が低下し等
軸晶が増え鋳片中心部のポロシティ（引け巣）欠陥が減
少するといった効果が期待される。Further, in the case of a single hole nozzle having one discharge hole at the bottom of the cylindrical nozzle, if a swirl flow nozzle is applied, the discharge flow is discharged while spreading due to centrifugal force.
Due to the electromagnetic brake effect that the discharge flow velocity decreases and the depth of the discharge flow entering the slab decreases, the floating of inclusions in the mold is promoted and the molten metal surface (meniscus) temperature in the mold rises. Expected to have the effect of promoting melting of the mold powder to improve the surface of the slab, reducing the temperature inside the slab and increasing equiaxed crystals to reduce porosity (shrinkage cavity) defects in the center of the slab. .
【図１】本発明に係る連続鋳造用浸漬ノズルの第１実施
例を断面して示した図である。FIG. 1 is a cross-sectional view showing a first embodiment of a continuous casting immersion nozzle according to the present invention.
【図２】ねじのモデル概念図である。FIG. 2 is a conceptual diagram of a screw model.
【図３】旋回流ノズルを採用した場合における旋回流形
成モデルを示した図である。FIG. 3 is a diagram showing a swirl flow formation model when a swirl flow nozzle is adopted.
【図４】タンディッシュと鋳型間の必要ヘッド予測値Ｈ
と実測値との相関を示した図である。FIG. 4 Predicted required head value H between tundish and mold
It is the figure which showed the correlation with the measured value.
【図５】本発明に係る連続鋳造用浸漬ノズルの第２実施
例を断面して示した図である。FIG. 5 is a cross-sectional view showing a second embodiment of the continuous casting immersion nozzle according to the present invention.
【図６】吐出流が鋳型長辺に向って吐出し、鋳型長辺衝
突時に著しく減衰する状況を模式的に示した図である。FIG. 6 is a diagram schematically showing a situation in which the discharge flow is discharged toward the long side of the mold and is significantly attenuated when the long side of the mold collides.
【図７】本発明に係る連続鋳造用浸漬ノズルの第３実施
例を吐出孔部分を横断面して示した図である。FIG. 7 is a cross-sectional view of a discharge hole portion of a third embodiment of the continuous casting immersion nozzle according to the present invention.
【図８】（ａ）（ｂ）は本発明に係る連続鋳造用浸漬ノ
ズルの第４実施例を吐出孔部分を横断面して示した図で
ある。FIGS. 8 (a) and 8 (b) are cross-sectional views of a discharge hole portion of a fourth embodiment of the continuous casting immersion nozzle according to the present invention.
【図９】旋回流ノズルの底部を縦断面して示した図で、
（ａ）は滝壷状凹部を形成しないもの、（ｂ）は滝壷状
凹部を形成したものである。FIG. 9 is a vertical cross-sectional view of the bottom of the swirl flow nozzle,
(A) does not have a waterfall-shaped recess, and (b) has a waterfall-shaped recess.
【図１０】旋回流ノズルの吐出孔の吐出角度が湯面に及
ぼす影響を示した図で、右半分は吐出角度が浅い場合、
左半分は吐出角度が適正な場合を示す。FIG. 10 is a diagram showing the influence of the discharge angle of the discharge hole of the swirl flow nozzle on the molten metal surface. In the right half, when the discharge angle is shallow,
The left half shows the case where the discharge angle is appropriate.
【図１１】本発明に係る連続鋳造用浸漬ノズルの第５実
施例を吐出孔部分を縦断面して示した図である。FIG. 11 is a vertical sectional view of a discharge hole portion of a fifth embodiment of the continuous casting immersion nozzle according to the present invention.
【図１２】旋回流ノズルが鋳型幅中央から５０ｍｍを越
えて偏って鋳込まれている状況を模式的に示した図であ
る。FIG. 12 is a diagram schematically showing a situation in which a swirl flow nozzle is cast while being biased more than 50 mm from the center of the mold width.
【図１３】旋回流ノズルの設置位置が品質に及ぼす影響
を示した図である。FIG. 13 is a diagram showing the influence of the installation position of the swirl flow nozzle on the quality.
【図１４】本発明に係る連続鋳造用浸漬ノズルの第６実
施例を断面して示した図である。FIG. 14 is a sectional view showing a sixth embodiment of the immersion nozzle for continuous casting according to the present invention.
【図１５】通常の単孔ノズル使用時における鋳型内流動
パターンを模式的に示した図である。FIG. 15 is a diagram schematically showing a flow pattern in a mold when using a normal single hole nozzle.
【図１６】２孔ノズルにより鋳型内に形成される流れと
電磁攪拌形成流との干渉状況を模式的に示した図であ
る。FIG. 16 is a diagram schematically showing an interference state between a flow formed in a mold by a two-hole nozzle and an electromagnetic stirring formation flow.
【図１７】旋回流ノズルと電磁攪拌を組合わせた場合の
メニスカス温度への影響を表わした図である。FIG. 17 is a diagram showing the influence on the meniscus temperature when a swirl flow nozzle and electromagnetic stirring are combined.
１ 旋回流ノズル １ａ 吐出孔 １ａａ 上壁 １ｂ ノズル孔 １ｃ 滝壷状凹部 ２ 旋回羽根 ３ 絞り部 1 swirl flow nozzle 1a Discharge hole 1aa top wall 1b nozzle hole 1c Waterfall-shaped recess 2 swirl vanes 3 throttle
フロントページの続き (72)発明者 川本 正幸 大阪府大阪市中央区北浜４丁目５番33号 住友金属工業株式会社内 (72)発明者 丸川 雄浄 大阪府大阪市中央区北浜４丁目５番33号 住友金属工業株式会社内 (72)発明者 原 茂太 大阪府吹田市山田丘２−１ 大阪大学工 学部内 (72)発明者 横谷 真一郎 埼玉県南埼玉郡宮代町学園台４−１ 日 本工業大学内 (72)発明者 野々部 和男 岡山県備前市浦伊部1175 九州耐火煉瓦 株式会社内 (56)参考文献 特開2000−237852（ＪＰ，Ａ) 特開2000−135549（ＪＰ，Ａ) 特開 平７−303949（ＪＰ，Ａ) 特開 平11−90593（ＪＰ，Ａ) 国際公開99／015291（ＷＯ，Ａ１) (58)調査した分野(Int.Cl.7，ＤＢ名) B22D 11/10 330 B22D 11/115 B22D 41/50 520 Front page continued (72) Inventor Masayuki Kawamoto 4-5-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Inventor Yujo Marukawa 4-53, Kitahama, Chuo-ku, Osaka City, Osaka Prefecture No. Sumitomo Metal Industries Co., Ltd. (72) Inventor Shigeta Hara 2-1 Yamadaoka, Suita City, Osaka Prefecture Faculty of Engineering, Osaka University (72) Inventor Shinichiro Yokotani 4-1, Miyashiro-cho, Minami-Saitama-gun, Saitama Nihon Kogyo University (72) Inventor Kazuo Nonobe 1175 Uraiebe, Bizen City, Okayama Prefecture Kyushu Fire Brick Co., Ltd. (56) Reference JP 2000-237852 (JP, A) JP 2000-135549 (JP, A) JP 7 -303949 (JP, A) JP-A-11-90593 (JP, A) International Publication 99/015291 (WO, A1) (58) Fields investigated (Int.Cl. 7 , DB name) B22D 11/10 330 B22D 11/115 B22D 41/50 520
Claims (12)
流量調整装置の下流側に取り付けられ、内部に捩り板型
旋回羽根を設置した浸漬ノズルであって、下記式に定
義される旋回羽根捩りピッチＰｃを０．８〜３．０、旋
回羽根捩り角θを６０〜１８０°、旋回羽根の外径（＝
２Ｒ）を５０〜２５０ｍｍ、旋回羽根の厚みを前記旋回
羽根の外径の５〜３０％とし、旋回羽根下端と吐出孔と
の間において内径を絞り、その絞り後の横断面積を下記
式で定義される旋回羽根部流路有効断面積Ｓｅの最小
値の０．５〜１．８倍の範囲内に設定すると共に、下記
式で示したタンディッシュと鋳型間の必要ヘッド予測
値Ｈを０．３〜２．０（ｍ）の範囲内におさめたことを
特徴とする連続鋳造用浸漬ノズル。 Ｐｃ＝Ｌ・π／（２・Ｒ・θ）… 但し、Ｌ：旋回羽根捩り部長さ（ｍｍ） Ｒ：旋回羽根半径（ｍｍ） θ：旋回羽根捩り角（ｒａｄ） Ｓｅ（ｍｍ2 ）＝ｓｉｎ（ｔａｎ-1（２・Ｐｃ・θ／π2 ））・Ｓ1 … 但し、Ｓ1 ：旋回羽根部横断面流路面積（ｍｍ2 ） Ｈ（ｍ）＝（５６０・Ｋ＋０．０６）・ＥＸＰ（０．０２４・ＴＰ）… 但し、ＴＰ：溶鋼スループット（ｋｇ／ｓｅｃ） Ｋ：旋回速度定数（ｍｍ2 ） 〔＝（Ｄ1 ／Ｄ2 ）・｛π／（２・Ｐｃ・Ｓ1 ）｝〕 Ｄ1 ：旋回羽根部ノズル内径（ｍｍ） Ｄ2 ：旋回羽根下端と吐出孔間における絞り後のノズル
内径（ｍｍ）1. A dipping nozzle, which is mounted on the downstream side of a flow rate adjusting device at the bottom of a continuous casting tundish and has a twisting plate type swirl vane installed therein, and has a swirl vane twist pitch Pc defined by the following formula. 0.8 to 3.0, swirl vane twist angle θ of 60 to 180 °, outer diameter of swirl vane (=
2R) is 50 to 250 mm, the thickness of the swirl blade is 5 to 30% of the outer diameter of the swirl blade, the inner diameter is narrowed between the lower end of the swirl blade and the discharge hole, and the cross-sectional area after the narrowing is defined by the following formula. The required head predicted value H between the tundish and the mold shown by the following equation is set to 0.5 to 1.8 times the minimum value of the effective sectional area Se of the swirl vane passage. An immersion nozzle for continuous casting, characterized by being kept within a range of 3 to 2.0 (m). Pc = L.pi ./ (2.R..theta.), Where L: swirl vane twist length (mm) R: swivel vane radius (mm) θ: swirl vane twist angle (rad) Se (mm 2 ) = sin (Tan −1 (2 · Pc · θ / π 2 )) · S 1 where S 1 : swirl vane cross-sectional flow path area (mm 2 ) H (m) = (560 · K + 0.06) · EXP (0.024 · TP) However, TP: Molten steel throughput (kg / sec) K: Turning rate constant (mm 2 ) [= (D 1 / D 2 ) · {π / (2 · Pc · S 1 )} ] D 1 : Swirling vane nozzle inner diameter (mm) D 2 : Nozzle inner diameter (mm) between the lower end of the swirl blade and the discharge hole
ュ底部のスライディングゲートの摺動方向と平行となる
ように設置されていることを特徴とする請求項１記載の
連続鋳造用浸漬ノズル。2. The immersion nozzle for continuous casting according to claim 1, wherein the dipping nozzle for continuous casting is installed such that the longitudinal direction of the upper end of the swirl vane is parallel to the sliding direction of the sliding gate at the bottom of the tundish.
流側において、内径を断面積で１０〜３５％縮減する絞
り部を設けたことを特徴とする請求項１又は２記載の連
続鋳造用浸漬ノズル。3. The immersion nozzle for continuous casting according to claim 1 or 2, wherein a throttle portion for reducing the inner diameter by 10 to 35% in cross-sectional area is provided on the upstream side within 200 mm from the upper end of the swirling blade. .
た請求項１〜３の何れか記載の連続鋳造用浸漬ノズルに
おいて、タンディッシュ底部の流量調整装置の下流側に
設置した際、２つの吐出孔からの吐出流が矩形断面鋳型
の長辺と平行に吐出するように、前記２つの吐出孔を鋳
型長辺と平行な線から反旋回方向に２〜１０°振った状
態となるように開設したことを特徴とする連続鋳造用浸
漬ノズル。4. The immersion nozzle for continuous casting according to any one of claims 1 to 3, which has two discharge holes facing each other in the vicinity of the bottom portion, when installed on the tundish bottom portion on the downstream side of the flow rate adjusting device. In order that the discharge flow from one discharge hole is discharged in parallel with the long side of the rectangular cross-section mold, the two discharge holes are in a state of being swung by 2 to 10 ° in a direction opposite to the swirl direction from a line parallel to the long side of the mold. Immersion nozzle for continuous casting characterized by being opened in.
た請求項１〜３の何れか記載の連続鋳造用浸漬ノズル
を、２つの吐出孔からの吐出流が矩形断面鋳型の長辺と
平行に吐出するように、前記２つの吐出孔が鋳型長辺と
平行な線から反旋回方向に２〜１０°振った状態となる
ように設置して鋳造することを特徴とする連続鋳造方
法。5. The continuous casting immersion nozzle according to claim 1, which has two discharge holes facing each other in the vicinity of the bottom, and the discharge flow from the two discharge holes is the long side of the rectangular cross-section mold. A continuous casting method characterized in that the two discharge holes are installed and cast so as to be in a state of being swung by 2 to 10 ° in a counter-rotating direction from a line parallel to the long side of the mold so as to discharge in parallel.
た請求項１〜３の何れか、又は、請求項４記載の連続鋳
造用浸漬ノズルにおいて、ノズル中心軸に対し点対称と
なるように底部近傍に開孔させた対向する２つの吐出孔
の、幅をノズル孔内径よりも小さい矩形状となるように
形成すると共に、これらの吐出孔の側壁の一方をノズル
孔内壁に沿う旋回流の旋回接線方向に倣って開孔させた
ことを特徴とする連続鋳造用浸漬ノズル。6. The continuous casting immersion nozzle according to claim 1, which has two discharge holes facing each other in the vicinity of the bottom, or the immersion nozzle for continuous casting according to claim 4, so as to be point-symmetric with respect to the central axis of the nozzle. The two opposing discharge holes opened near the bottom are formed to have a rectangular shape with a width smaller than the inner diameter of the nozzle hole, and one of the side walls of these discharge holes is swirled along the inner wall of the nozzle hole. An immersion nozzle for continuous casting, characterized in that a hole is formed along the swirl tangential direction of.
を設け、ノズル中心軸に対し点対称となるように底部近
傍に開孔させた対向する２つの吐出孔からの吐出角度が
下向きに１５〜４０°で鋳型内湯面（メニスカス）の平
均流速が２０〜６０ｃｍ／ｓｅｃになるよう吐出孔形状
が調整されて設けられていることを特徴とする底部近傍
に対向する２つの吐出孔を有した請求項１〜３の何れ
か、或いは、請求項４又は６記載の連続鋳造用浸漬ノズ
ル。7. A waterhole-shaped recess having a depth of 5 to 30 mm is provided at the bottom, and the ejection angles from two opposing ejection holes opened near the bottom so as to be point-symmetric with respect to the central axis of the nozzle are downward. The discharge hole shape is adjusted so that the average flow velocity of the molten metal surface (meniscus) in the mold at 15 to 40 ° is 20 to 60 cm / sec. Two discharge holes facing each other are provided near the bottom. The immersion nozzle for continuous casting according to any one of claims 1 to 3 or claim 4 or 6 having.
ｍｍの円弧状となし、ノズル孔内壁から吐出孔上壁に向
って拡管状断面を有するように成形したことを特徴とす
る底部近傍に対向する２つの吐出孔を有した請求項１〜
３の何れか、或いは、請求項４又は６又は７記載の連続
鋳造用浸漬ノズル。8. The radius R1 of the upper wall of the discharge hole is 40 to 180.
mm-shaped arc, and formed so as to have an expanded tubular cross section from the inner wall of the nozzle hole toward the upper wall of the discharge hole, characterized by having two discharge holes facing each other near the bottom.
The immersion nozzle for continuous casting according to any one of claims 3 or 4 or 6 or 7.
に設置した請求項１〜４、６〜８の何れか記載の連続鋳
造用浸漬ノズルを介して溶鋼を供給することを特徴とす
るスラブの連続鋳造方法。9. A slab characterized in that molten steel is supplied through the continuous casting immersion nozzle according to any one of claims 1 to 4 and 6 to 8 which is installed within 50 mm from the center of the width of the rectangular cross-section mold. Continuous casting method.
との連続部分を、半径Ｒ2 が４０〜１８０ｍｍの円弧状
となし、ノズル孔内壁から吐出孔に向って拡管状断面を
有するように成形したことを特徴とする底の無い単孔の
吐出孔を有した請求項１〜３の何れか記載の連続鋳造用
浸漬ノズル。10. The bottomless single-hole discharge hole is connected to the inner wall of the nozzle hole in an arc shape having a radius R2 of 40 to 180 mm, and has an expanded tubular cross section from the inner wall of the nozzle hole toward the discharge hole. The immersion nozzle for continuous casting according to any one of claims 1 to 3, which has a single-hole discharge hole having no bottom, which is formed by molding.
ルを用い、かつ、旋回方向と同方向の水平循環流を形成
するよう鋳型内を電磁攪拌することを特徴とするスラブ
の連続鋳造方法。11. A continuous casting method for a slab, which comprises using the immersion nozzle for continuous casting according to claim 10 and electromagnetically stirring the inside of the mold so as to form a horizontal circulating flow in the same direction as the swirling direction.
ルを用い、鋳型内電磁攪拌を実施しないことを特徴とす
る丸ビレットの連続鋳造方法。12. A continuous casting method for a round billet, wherein the immersion nozzle for continuous casting according to claim 10 is used and electromagnetic stirring in a mold is not carried out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001045097A JP3515762B2 (en) | 2001-02-21 | 2001-02-21 | Immersion nozzle for continuous casting and continuous casting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001045097A JP3515762B2 (en) | 2001-02-21 | 2001-02-21 | Immersion nozzle for continuous casting and continuous casting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2002239690A JP2002239690A (en) | 2002-08-27 |
| JP3515762B2 true JP3515762B2 (en) | 2004-04-05 |
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ID=18906959
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001045097A Expired - Fee Related JP3515762B2 (en) | 2001-02-21 | 2001-02-21 | Immersion nozzle for continuous casting and continuous casting method |
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Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3861861B2 (en) * | 2003-08-04 | 2006-12-27 | 住友金属工業株式会社 | Immersion nozzle for continuous casting and continuous casting method |
| JP4343907B2 (en) * | 2003-08-22 | 2009-10-14 | 黒崎播磨株式会社 | Immersion nozzle for continuous casting of steel and method for continuous casting of steel using the same |
| JP4549112B2 (en) * | 2004-06-17 | 2010-09-22 | 株式会社神戸製鋼所 | Continuous casting method |
| JP4553639B2 (en) * | 2004-06-17 | 2010-09-29 | 株式会社神戸製鋼所 | Continuous casting method |
| JP4456491B2 (en) * | 2005-01-20 | 2010-04-28 | 新日本製鐵株式会社 | Porous immersion nozzle and continuous casting method using the same |
| CN100333865C (en) * | 2005-08-03 | 2007-08-29 | 东北大学 | Molten steel spin type continuous casting pouring basket |
| EP1952913B1 (en) * | 2005-10-27 | 2018-06-20 | Nippon Steel & Sumitomo Metal Corporation | Method for manufacture of ultra-low carbon steel slab |
| CN102781605B (en) * | 2009-11-06 | 2014-11-05 | 新日铁住金株式会社 | Continuous casting method for molten metal |
| JP5347922B2 (en) * | 2009-11-30 | 2013-11-20 | 新日鐵住金株式会社 | Immersion nozzle for continuous casting and continuous casting method |
| JP6331810B2 (en) * | 2014-07-18 | 2018-05-30 | 新日鐵住金株式会社 | Metal continuous casting method |
| JP7115230B2 (en) * | 2018-11-07 | 2022-08-09 | 日本製鉄株式会社 | Pouring equipment for continuous casting |
| CN117718467B (en) * | 2023-12-14 | 2024-06-28 | 东北大学 | Electromagnetic rotational flow enhanced submerged nozzle |
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