JPH0461739B2 - - Google Patents
Info
- Publication number
- JPH0461739B2 JPH0461739B2 JP31614487A JP31614487A JPH0461739B2 JP H0461739 B2 JPH0461739 B2 JP H0461739B2 JP 31614487 A JP31614487 A JP 31614487A JP 31614487 A JP31614487 A JP 31614487A JP H0461739 B2 JPH0461739 B2 JP H0461739B2
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- nozzle
- discharge hole
- discharge
- flow
- 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
Links
- 229910000831 Steel Inorganic materials 0.000 claims description 42
- 239000010959 steel Substances 0.000 claims description 42
- 238000007654 immersion Methods 0.000 claims description 18
- 238000009749 continuous casting Methods 0.000 claims description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000005266 casting Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 230000005499 meniscus Effects 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
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
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
Description
＜産業上の利用分野＞
本発明は、鋼の製造特にパウダー性介在物、酸
化物系非金属介在物の少ない清浄鋼に連続鋳造に
用いる浸漬ノズルに関するものである。
＜従来の技術＞
従来、鋼の連続鋳造に際して、注入溶鋼中に含
まれている酸化物系非金属介在物などが注入溶鋼
流によつて鋳片内部に深く巻きこまれることが問
題となつており、特に、湾曲型の連鋳機では、一
旦深く巻き込まれた非金属介在物がメニスカス部
分にまで浮上することがなく、凝固殻の下面に把
えられ、圧延後の鋼板の表面にスリバー、ブリス
ター等の欠陥が発生するという問題が生じてい
る。
上記した問題を解決する技術として特開昭61−
23558号（先行技術１）、実開昭55−88347号（先
行技術２）に浸漬ノズルを改良して溶鋼流の未凝
固域内への侵入を防ぐ技術が開示されている。
第５図に示した先行技術１にかける浸漬ノズル
は、ノズル先端が半球状に湾曲しておりそこに設
けられた３個以上の吐出孔から溶鋼を流出させる
ものである。また第６図に示した浸漬ノズルは、
ノズル下端に互いに反対方向に水平または斜め上
向きに開孔した２個の吐出孔の直上に斜め下向き
に開孔した２個の吐出孔を有し、流出する溶鋼を
衝突させようとするものである。
これらのノズルについては、ノズル内部を通過
する溶鋼流速が大きくなると、下端の吐出孔のみ
から溶鋼は流出し、かえつて下向きの速い流れを
助長し溶鋼の侵入深さを大きくしてしまうという
問題点がある。
＜発明が解決しようとする問題点＞
本発明は、従来の浸漬ノズルでは溶鋼流の鋳片
内部への侵入深さが深く、非金属介在物の巻き込
みを完全に防止することが困難であつたので、吐
出孔からの流出速度を均一化し溶鋼流に伴う気
泡、非金属介在物の浮上を促進させ欠陥のより少
ない鋳片を製造する浸漬ノズルを提供するために
なされたものである。
＜問題点を解決するための手段＞
本発明者らは、浸漬ノズルの吐出孔からの流出
速度の均一化について鋭意研究を重ねた結果、左
右対称に、かつ縦方向にそれぞれ複数個の吐出孔
を設け、浸漬ノズルの溶鋼通路を下部ほど小さく
することによつて目的を達成できるとの知見を
得、この知見にもとづいて本発明をなすに至つ
た。
本発明は、有底円筒ノズルの高さ方向に吐出口
を左右対称に複数個設けてなる浸漬ノズルであつ
て、浸漬ノズルのの高さ方向に貫通する溶鋼通路
の断面積を下部に向つて段階的に細くなるような
段差部を設け、その段差部ごとに吐出孔を設ける
と共に、各吐出孔の断面積（上から順にs1，s2，
…so-1，so）と各吐出孔に対応する溶鋼通路の断
面積（上から順にS1，S2…So-1，So）について下
記の関係を満足させたことを特徴とする連続鋳造
用浸漬ノズルである。
記
K2〔S2／S1〕3＝〔s2＋…＋so／s1＋s2＋…＋so〕2…
…(1)
〓〔S3／S2〕3＝〔s3＋…＋so／s2＋s3＋…＋so
〕2……(2)
〓
〔so／so-1〕3＝〔so／so-1＋so〕2 ……(n)
0.7≦Ｋ≦1.0
＜作 用＞
本発明に係る浸漬ノズル形状の一例を第１図に
示した。この形状を選んだ理由を以下に説明す
る。
吐出孔を浸漬ノズルの縦方向に設置する場合に
吐出孔面積、溶鋼通路断面積の関係で必ずしも溶
鋼流は、各吐出孔から均一には流出しない。
下部吐出孔のみから溶鋼が流出するときには、
遠い下降流となり、溶鋼流が鋳片の深くまで侵入
する。また上部の吐出孔のみから溶鋼が流出する
ときには、湯面変動が激しくなりパウダの巻き込
みを生ずる。これらを防ぐためには各吐出孔から
溶鋼が等速度で流出できるようにすることが肝要
である。
本発明者らの研究の結果、円筒形浸漬ノズルに
おける上部吐出孔と下部吐出孔とからの溶鋼吐出
流のアンバランスは、ノズル内流速の速い上部は
ベルヌーイの法則にしたがつて静圧が小さいため
であることに起因することが判明した。従つて、
浸漬ノズルの下部を細くすることによつて溶鋼吐
出流のバランスが得られることが判つた。
ここで、吐出孔面積と溶鋼通路の絞り方の条件
を以下に説明する。
第２図に本発明の浸漬ノズルにおける溶鋼通路
面積、吐出孔面積、溶鋼流速の関係をそれぞれ記
号で示した。なお、上部吐出孔からの流出の駆動
力は絞り部で発生する動圧によるものとする。
吐出孔２段の場合；
連続の式
S1U1＝2K′s1U＋KS2U2 ……(a)
KS2U2＝2K′s2U ……(b)
ベルヌーイの式
(a)〜(d)より
〔s2／s1＋s2〕2＝K2・〔S2／S1〕 ……(e)
吐出孔３段の場合；
連続式
S1U1＝2K′s1U＋KS2U2 ……(f)
KS2U2＝2K′s2U＋KS3U3 ……(g)
KS3U3＝2K′s3U ……(h)
ベルヌーイの式
(f)〜(l)より
K2〔S2／S1〕3＝〔s2＋s3／s1＋s2＋s3〕2……（ｍ）
〔S3／S2〕＝〔s3／s2＋s3〕2 ……（ｏ）
なお、同様に吐出孔ｎ段の場合は以下の通りで
ある。
K2〔S2／S1〕3＝〔s2＋…＋so／s1＋s2＋…＋so〕2…
…(1)
〔S3／S2〕3＝〔s3＋…＋so／s2＋s3＋…＋so〕2……
(2)
〓
〔So／So-1〕3＝〔so／so-1＋so〕2 ……(n)
以上の式によつて吐出孔面積と溶鋼通路面積の
関係が決まる。
なお、吐出孔を４段以上にすることもできるが
上部吐出孔がメニスカスに近づき湯面変動を増大
させる恐れがあるので吐出孔２〜３段が最適であ
る。
ここでＫ，K′は流出係数であり、厳密には各
流出部におけるＫ，K′の値は異なる訳であるが、
近似的に縦方向の流出係数はＫ、横方向の流出係
数はK′（これは式の導出過程で消去され、実用的
影響はない）でそれぞれ一定であると仮定でき
る。
Ｋは前記のとおり流出係数で、経済的に0.8程
度の値となるものである。各流路断面としては
(13)，(14)式を満足する理想条件を多少外れても実用
上は許される。実用上許される断面積の範囲をＫ
に含めて表現しなおした許容係数（×Ｋ）をあら
ためてＫと定義しなおすとＫが１以下0.7以上の
条件が本発明における許容好適範囲といえる。第
３図に斜線で示した適正範囲は、Ｋが0.7以上1.0
以下になるための吐出孔面積と溶鋼通路断面積比
との関係を示したものであり、ノズルの設計にあ
たり、この適正範囲を満足させるように吐出孔断
面積比、溶鋼通路断面積比を設定すればよい。
吐出孔が２段の場合、あらかじめ吐出孔面積
s1，s2を定めておくと、〔s2／s1＋s2〕2＝K2〔S2／S1
〕3か
ら溶鋼通路の面積比が決まる。溶鋼通路面積はノ
ズルの大きさによつて制限されるから、許容でき
る範囲で、S1を定めるとS2も計算される。
吐出孔が３段の場合も同様に、３つの吐出孔面
積s1，s2，s3を決めておく。まず、
〔S3／S2〕3＝〔s3／s2＋s3〕2より、溶鋼通路の下部
２段
の面積比が決まり、S3をノズルの大きさに従つて
決めるとS2が計算される。また、S2の大きさも、
K2〔S2／S1〕3＝〔s2＋s3／s1＋s2＋s3〕3の式に以上の
計算によ
つて算出した、s1，s2，s3，S1，S2を代入するこ
とによつて求められる。
この式より計算される上下の吐出流速を均一に
する吐出孔面積比（上部／上部＋下部）と溶鋼通
路面積比（下部／上部）の範囲は第３図の実線に
はさまれる範囲である。しかしながら水モデルで
検証した結果、上部吐出孔もしくは下部吐出孔が
著しく小さくなつた場合、偏流、負圧領域の増加
がおこり、吐出孔面積（上部／上部＋下部）が
0.2〜0.8の範囲でないと流速の均一性が保たれな
かつた。よつて、適正範囲は第３図の斜線の範囲
である。また第３図中には上下吐出孔における最
大流速比の等高線も示してある。斜線部はほぼ最
大流速比1.4以内にある。
吐出孔面積を通常のノズルの1.7倍にし、上下
の吐出孔における最大流速比が1.0〜1.9の各ノズ
ルを用い、鋳込速度1.5m／minで鋳造し、鋳片中
に検出された介在物の評価を第４図に示す。最大
流速比が、1.4以上になると、介在物が増加する。
また通常のノズルでは介在物評点は5.0であつた。
＜実施例＞
(e)式に基づいた吐出孔２段の本発明に係る浸漬
ノズルを製作し2.5t／min、4.0t／minの給湯量の
場合に、各吐出孔における流速比をあらかじめ水
モデルを用いピトー管で測定し、またそのヒート
の鋳片から試料を採取して介在物の評価を行つ
た。同時に第６図に示すような従来浸漬ノズルに
ついても、好適範囲から外れる比較例として同一
条件で鋳造し、同様に測定、評価を行い、その結
果を第１表に示した。
第１表からわかるように本発明の浸漬ノズルを
使用することによつて介在物評点が半減しており
成品の品質向上に効果があることが明らかであ
る。
<Industrial Application Field> The present invention relates to an immersion nozzle used for continuous casting of steel, particularly clean steel with few powdery inclusions and oxide nonmetallic inclusions. <Conventional technology> Conventionally, when continuously casting steel, there has been a problem that oxide-based nonmetallic inclusions contained in the injected molten steel are deeply engulfed inside the slab by the injected molten steel flow. In particular, in a curved continuous casting machine, non-metallic inclusions that are deeply rolled up do not float up to the meniscus area, but are caught on the lower surface of the solidified shell, forming slivers and blisters on the surface of the rolled steel sheet. The problem is that defects such as the following occur. As a technology to solve the above problems, JP-A-61-
No. 23558 (prior art 1) and Utility Model Application Publication No. 55-88347 (prior art 2) disclose techniques for improving the immersion nozzle to prevent the molten steel flow from entering the unsolidified region. The immersion nozzle used in Prior Art 1 shown in FIG. 5 has a hemispherically curved nozzle tip and allows molten steel to flow out from three or more discharge holes provided therein. In addition, the immersion nozzle shown in Fig. 6 is
The nozzle has two discharge holes that are opened horizontally or diagonally upward in opposite directions at the lower end of the nozzle, and two discharge holes that are opened diagonally downward directly above the nozzle to cause the flowing molten steel to collide. . The problem with these nozzles is that when the flow velocity of molten steel increases inside the nozzle, the molten steel flows out only from the discharge hole at the bottom end, which instead promotes a fast downward flow and increases the penetration depth of the molten steel. There is. <Problems to be Solved by the Invention> The present invention solves the problem that with conventional immersion nozzles, the molten steel flow penetrates deep into the slab, making it difficult to completely prevent non-metallic inclusions from being entrained. Therefore, this method was developed in order to provide a submerged nozzle that uniformizes the outflow velocity from the discharge hole, promotes the floating of bubbles and nonmetallic inclusions accompanying the flow of molten steel, and produces slabs with fewer defects. <Means for Solving the Problems> As a result of extensive research into uniforming the outflow velocity from the discharge holes of a submerged nozzle, the inventors of the present invention have determined that a plurality of discharge holes are symmetrically arranged horizontally and vertically. The inventors have found that the objective can be achieved by making the molten steel passage of the immersion nozzle smaller toward the bottom. Based on this knowledge, the present invention has been completed. The present invention is an immersed nozzle in which a plurality of discharge ports are symmetrically provided in the height direction of a bottomed cylindrical nozzle, and the cross-sectional area of a molten steel passage passing through the immersed nozzle in the height direction is directed toward the bottom. Steps are provided that gradually become thinner, and a discharge hole is provided for each step.
...s o-1 , s o ) and the cross-sectional area of the molten steel passage corresponding to each discharge hole (from top to bottom: S 1 , S 2 ...S o-1 , S o ) satisfy the following relationship. This is an immersion nozzle for continuous casting. Note K 2 [S 2 /S 1 ] 3 = [s 2 +…+s o /s 1 +s 2 +…+s o ] 2 …
…(1) 〓[S 3 /S 2 ] 3 = [s 3 +…+s o /s 2 +s 3 +…+s o
] 2 ...(2) 〓 [s o /s o-1 ] 3 = [s o /s o-1 +s o ] 2 ...(n) 0.7≦K≦1.0 <Function> Immersion according to the present invention An example of the nozzle shape is shown in FIG. The reason for choosing this shape will be explained below. When the discharge holes are installed in the vertical direction of the immersion nozzle, the molten steel flow does not necessarily flow uniformly from each discharge hole due to the relationship between the discharge hole area and the molten steel passage cross-sectional area. When molten steel flows out only from the lower discharge hole,
The flow becomes a far downward flow, and the molten steel flow penetrates deep into the slab. Further, when molten steel flows out only from the upper discharge hole, the molten metal level fluctuates rapidly, causing powder to be dragged into the molten steel. In order to prevent these, it is important to allow molten steel to flow out from each discharge hole at a uniform speed. As a result of the research conducted by the present inventors, the unbalance of the molten steel discharge flow from the upper discharge hole and the lower discharge hole in a cylindrical submerged nozzle is caused by the fact that the upper part, where the flow velocity inside the nozzle is faster, has lower static pressure according to Bernoulli's law. It turns out that this is due to the fact that Therefore,
It was found that the balance of the molten steel discharge flow could be obtained by narrowing the lower part of the immersion nozzle. Here, the conditions for the discharge hole area and how to narrow the molten steel passage will be explained below. FIG. 2 shows the relationships among the molten steel passage area, discharge hole area, and molten steel flow rate in the immersion nozzle of the present invention, respectively, using symbols. Note that the driving force for outflow from the upper discharge hole is due to the dynamic pressure generated in the constriction section. In the case of two stages of discharge holes; Continuity equation S 1 U 1 = 2K′s 1 U + KS 2 U 2 ……(a) KS 2 U 2 = 2K′s 2 U ……(b) Bernoulli equation From (a) to (d), [s 2 /s 1 +s 2 ] 2 = K 2・[S 2 /S 1 ] ...(e) In case of 3 stages of discharge holes; Continuous type S 1 U 1 = 2K' s 1 U＋KS 2 U 2 ...(f) KS 2 U 2 =2K′s 2 U+KS 3 U 3 ...(g) KS 3 U 3 =2K′s 3 U ...(h) Bernoulli's equation From (f) to (l), K 2 [S 2 /S 1 ] 3 = [s 2 +s 3 /s 1 +s 2 +s 3 ] 2 ... (m) [S 3 /S 2 ] = [s 3 / s 2 +s 3 ] 2 ...(o) Similarly, in the case of n stages of discharge holes, the equation is as follows. K 2 [S 2 /S 1 ] 3 = [s 2 +…+s o /s 1 +s 2 +…+s o ] 2 …
…(1) [S 3 /S 2 ] 3 = [s 3 +…+s o /s 2 +s 3 +…+s o ] 2 …
(2) 〓 [S o /S o-1 ] 3 = [s o /s o-1 + s o ] 2 ...(n) The relationship between the discharge hole area and the molten steel passage area is determined by the above formula. Although it is possible to have four or more stages of discharge holes, it is optimal to have two to three stages of discharge holes because the upper discharge hole approaches the meniscus and may increase fluctuations in the melt level. Here, K and K' are runoff coefficients, and strictly speaking, the values of K and K' at each outlet are different, but
Approximately, it can be assumed that the runoff coefficient in the vertical direction is constant at K and the runoff coefficient in the horizontal direction is K' (these are eliminated in the process of deriving the equation and have no practical effect). As mentioned above, K is the runoff coefficient, which has an economical value of about 0.8. The cross section of each flow path is
It is practically acceptable even if the ideal condition of satisfying equations (13) and (14) is slightly deviated from. K is the range of cross-sectional area that is allowed in practice.
If we redefine the tolerance coefficient (×K) expressed as K, the condition where K is 1 or less and 0.7 or more can be said to be the preferred tolerance range in the present invention. The appropriate range indicated by diagonal lines in Figure 3 is K of 0.7 or more and 1.0.
This shows the relationship between the discharge hole area and the molten steel passage cross-sectional area ratio to achieve the following, and when designing the nozzle, set the discharge hole cross-sectional area ratio and the molten steel passage cross-sectional area ratio to satisfy this appropriate range. do it. If there are two stages of discharge holes, the discharge hole area should be determined in advance.
If s 1 and s 2 are determined, [s 2 /s 1 +s 2 ] 2 = K 2 [S 2 /S 1
] The area ratio of the molten steel passage is determined from 3 . Since the molten steel passage area is limited by the size of the nozzle, once S 1 is determined, S 2 is also calculated within an allowable range. In the case where there are three stages of discharge holes, the areas of the three discharge holes s 1 , s 2 , and s 3 are determined in the same way. First, the area ratio of the lower two stages of the molten steel passage is determined from [S 3 /S 2 ] 3 = [s 3 /s 2 +s 3 ] 2 , and if S 3 is determined according to the nozzle size, S 2 becomes calculated. The size of S 2 is also calculated by the above calculation using the formula K 2 [S 2 /S 1 ] 3 = [s 2 + s 3 /s 1 + s 2 + s 3 ] 3 , s 1 , s 2 , s 3 , S 1 , and S 2 . The range of the discharge hole area ratio (upper/upper + lower) and molten steel passage area ratio (lower/upper) that equalizes the upper and lower discharge flow speeds calculated from this formula is the range between the solid lines in Figure 3. . However, as a result of verification using a water model, if the upper or lower discharge hole becomes significantly smaller, drifting and negative pressure areas will occur, and the discharge hole area (upper/upper + lower) will decrease.
Uniformity of flow rate could not be maintained unless it was in the range of 0.2 to 0.8. Therefore, the appropriate range is the shaded range in FIG. Also shown in FIG. 3 are contour lines of the maximum flow velocity ratio in the upper and lower discharge holes. The shaded area is approximately within the maximum flow velocity ratio of 1.4. Inclusions detected in the slab were cast using nozzles with a discharge hole area 1.7 times that of a normal nozzle and a maximum flow velocity ratio of 1.0 to 1.9 between the upper and lower discharge holes at a casting speed of 1.5 m/min. The evaluation is shown in Figure 4. When the maximum flow velocity ratio becomes 1.4 or more, inclusions increase.
In addition, the inclusion rating for the normal nozzle was 5.0. <Example> A submerged nozzle according to the present invention with two stages of discharge holes was manufactured based on equation (e), and in the case of hot water supply rates of 2.5 t/min and 4.0 t/min, the flow velocity ratio at each discharge hole was determined in advance. Measurements were made using a pitot tube using a model, and samples were taken from the heat slab to evaluate inclusions. At the same time, a conventional immersion nozzle as shown in FIG. 6 was also cast under the same conditions as a comparative example outside the preferred range, and similarly measured and evaluated, and the results are shown in Table 1. As can be seen from Table 1, by using the immersion nozzle of the present invention, the inclusion score was halved, and it is clear that the use of the immersion nozzle of the present invention is effective in improving the quality of the product.
【表】
＜発明の効果＞
本発明は浸漬ノズルを使用することによつて、
溶鋼流の鋳片内部への侵入深さを浅くし、非金属
介在物の鋳片への巻き込み量を低減し、鋳片の品
質の向上ができた。[Table] <Effects of the invention> By using a submerged nozzle, the present invention
The penetration depth of the molten steel flow into the slab was made shallower, the amount of non-metallic inclusions entrained in the slab was reduced, and the quality of the slab was improved.
第１図ａは、本発明の浸漬ノズルの正面図、第
１図ｂはその側面図、第２図は、本発明の浸漬ノ
ズルの吐出孔面積、溶鋼通路面積の説明図、第３
図は、吐出孔面積比と溶鋼通路面積比の適正範囲
を示す特性図、第４図は、浸漬ノズルの最大流速
比と介在物評価との関係を示す特性図、第５図ａ
は、従来ノズルの正面断面図、第５図ｂはその側
面図、第６図は、従来ノズルの正面断面図であ
る。
１…浸漬ノズル、２…吐出孔、３…溶鋼通路。
FIG. 1a is a front view of the immersion nozzle of the present invention, FIG. 1b is a side view thereof, FIG. 2 is an explanatory diagram of the discharge hole area and molten steel passage area of the immersion nozzle of the present invention, and FIG.
Figure 4 is a characteristic diagram showing the appropriate range of the discharge hole area ratio and molten steel passage area ratio, Figure 4 is a characteristic diagram showing the relationship between the maximum flow velocity ratio of the submerged nozzle and inclusion evaluation, and Figure 5 a.
5 is a front sectional view of the conventional nozzle, FIG. 5b is a side view thereof, and FIG. 6 is a front sectional view of the conventional nozzle. 1... Immersion nozzle, 2... Discharge hole, 3... Molten steel passage.
Claims (1)
称に複数個設けてなる浸漬ノズルであつて、浸漬
ノズルの高さ方向に貫通する溶鋼通路の断面積を
下部に向かつて段階的に細くなるような段差部を
設け、その段差部ごとに吐出孔を設けると共に、
各吐出孔の断面積（上から順にs1，s2…so-1，so）
と各吐出孔に対応する溶鋼通路の断面積（上から
順にs1，s2…so-1，so）について下記の関係を満
足させたことを特徴とする連続鋳造用浸漬ノズ
ル。 記 K2〔S2／S1〕3＝〔s2＋…＋so／s1＋s2＋…＋so〕2…
…(1) 〔S3／S2〕3＝〔s3＋…＋so／s2＋s3＋…＋so〕2…
…(2) 〓 〓〔so／so-1〕3＝〔so／so-1＋so〕2……（ｎ） 0.7≦Ｋ≦1.0[Scope of Claims] 1. A submerged nozzle comprising a bottomed cylindrical nozzle with a plurality of discharge ports symmetrically provided in the height direction, the cross-sectional area of the molten steel passage passing through the submerged nozzle in the height direction being set at the bottom. In addition to providing a step portion that gradually becomes thinner towards the end, and providing a discharge hole for each step portion,
Cross-sectional area of each discharge hole (from top to bottom: s 1 , s 2 ... s o-1 , s o )
An immersion nozzle for continuous casting, characterized in that the following relationship is satisfied with respect to the cross-sectional area of the molten steel passage corresponding to each discharge hole (s 1 , s 2 . . . s o-1 , s o in order from the top). Note K 2 [S 2 /S 1 ] 3 = [s 2 +…+s o /s 1 +s 2 +…+s o ] 2 …
…(1) [S 3 /S 2 ] 3 = [s 3 +…+s o /s 2 +s 3 +…+s o ] 2 …
…(2) 〓 〓[s o /s o-1 ] 3 = [s o /s o-1 +s o ] 2 …(n) 0.7≦K≦1.0
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62316144A JPH01157751A (en) | 1987-12-16 | 1987-12-16 | Submerged nozzle for continuous casting |
| US07/283,789 US4949778A (en) | 1987-12-16 | 1988-12-13 | Immersion nozzle for continuous casting |
| EP88311821A EP0321206B1 (en) | 1987-12-16 | 1988-12-14 | Immersion nozzle for continuous casting |
| DE8888311821T DE3861957D1 (en) | 1987-12-16 | 1988-12-14 | SUBMERSIBLE PIPE FOR CONTINUOUS CASTING. |
| KR1019880016815A KR960004421B1 (en) | 1987-12-16 | 1988-12-15 | Immersion nozzle for continuous casting |
| CA000585951A CA1318766C (en) | 1987-12-16 | 1988-12-15 | Immersion nozzle for continuous casting |
| BR888806679A BR8806679A (en) | 1987-12-16 | 1988-12-16 | IMMERSION TUBE FOR CONTINUOUS CASTING AND CONTINUOUS CASTING PROCESS |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62316144A JPH01157751A (en) | 1987-12-16 | 1987-12-16 | Submerged nozzle for continuous casting |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01157751A JPH01157751A (en) | 1989-06-21 |
| JPH0461739B2 true JPH0461739B2 (en) | 1992-10-01 |
Family
ID=18073754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62316144A Granted JPH01157751A (en) | 1987-12-16 | 1987-12-16 | Submerged nozzle for continuous casting |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01157751A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
-
1987
- 1987-12-16 JP JP62316144A patent/JPH01157751A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01157751A (en) | 1989-06-21 |
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