JPH11314142A - Nozzle for continuous casting - Google Patents
Nozzle for continuous castingInfo
- Publication number
- JPH11314142A JPH11314142A JP13419998A JP13419998A JPH11314142A JP H11314142 A JPH11314142 A JP H11314142A JP 13419998 A JP13419998 A JP 13419998A JP 13419998 A JP13419998 A JP 13419998A JP H11314142 A JPH11314142 A JP H11314142A
- Authority
- JP
- Japan
- Prior art keywords
- nozzle
- cross
- gas
- hole
- continuous casting
- 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.)
- Pending
Links
Landscapes
- Continuous Casting (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は鋼の連続鋳造の方法
において、タンディッシュノズルの閉塞とノズルの内壁
の溶損を同時に防止しながら、圧延後の製品品質の優れ
た鋳片を製造するための連続鋳造方法に関する。[0001] The present invention relates to a method for continuous casting of steel, which is intended to produce a slab of excellent product quality after rolling while simultaneously preventing blockage of a tundish nozzle and erosion of the inner wall of the nozzle. A continuous casting method.
【0002】[0002]
【従来の技術】従来からタンディッシュノズルの材質と
しては、一般的にはハイアルミナ質が使用されている
が、アルミキルド鋼の鋳造に際して非金属介在物である
Al2 O3 クラスターがノズル内孔表面に付着し、ノズ
ル閉塞を発生し易い欠点を有していた。2. Description of the Related Art Conventionally, a high alumina material is generally used as a material for a tundish nozzle. However, Al 2 O 3 clusters, which are nonmetallic inclusions, are cast on the surface of the nozzle bore when casting aluminum killed steel. And had a disadvantage that the nozzle was easily clogged.
【0003】タンディッシュ上部ノズル材質がたとえ他
の材質であっても多連続鋳造(連々鋳)、例えば数チャ
ージ分の取鍋内溶鋼を鋳込むような場合には、取鍋交換
前の溶鋼温度の低下もAl2 O3 付着現象を助長する一
因となり、徐々にAl2 O3の付着が進行し、最終的に
はノズル閉塞が発生して鋳造不可能になってしまうケー
スが度々発生し、多大な損害を被り、改善を求められて
いた。ノズル内にAl2 O3 が付着することは、鋳造中
にノズルがやがて閉塞して鋳造速度を低下しなければな
らなくなったり、ノズル上方から閉塞部を洗浄する必要
が生じ、鋳造スラブの品質を悪化させたり、鋳造操業面
で支障をきたすことが多発していた。[0003] Even if the material of the upper nozzle of the tundish is another material, in the case of continuous casting (sequential casting), for example, when casting molten steel in the ladle for several charges, the molten steel temperature before the ladle replacement is changed. reduction also contribute to promote the Al 2 O 3 deposition phenomenon, gradually Al 2 deposition of O 3 proceeds, eventually case often occurs that becomes impossible casting nozzle clogging occurs , Suffered enormous damage and had to be improved. The adhesion of Al 2 O 3 in the nozzle may cause the nozzle to eventually block during casting and reduce the casting speed, or it may be necessary to clean the closed portion from above the nozzle, thereby reducing the quality of the casting slab. It often deteriorated or hindered the casting operation.
【0004】上述のようなノズル閉塞を防止するために
種々の方法が考えられ、ノズル内面に不活性ガスを流出
させ、ノズル内面に付着するAl2 O3 の付着または地
金の付着を防止する技術が開発されている(例えば、実
開平1−33257号公報、特開平4−319055号
公報等)。Various methods are conceivable to prevent the nozzle blockage as described above. An inert gas is caused to flow out to the inner surface of the nozzle to prevent Al 2 O 3 from adhering to the inner surface of the nozzle or the metal. Techniques have been developed (for example, Japanese Utility Model Laid-Open No. 1-3257, JP-A-4-319055).
【0005】図7は上記公報に開示された従来のノズル
の一例を示したもので、ノズル1の本体の肉厚部の内部
にガスプール2を設け、該ガスプール2に外部から不活
性ガスを供給管4を通して供給し、ガスプール内の上・
下方向(長手方向)にノズル内面5に向けて設けた複数
個のガス流出路3を通して不活性ガスをノズル内面5に
流出せしめAl2 O3 等がノズル内面5に付着するのを
防止している。FIG. 7 shows an example of a conventional nozzle disclosed in the above-mentioned publication, in which a gas pool 2 is provided inside a thick portion of a main body of a nozzle 1, and an inert gas is externally provided in the gas pool 2. Is supplied through the supply pipe 4 and is
The inert gas is caused to flow out to the nozzle inner surface 5 through a plurality of gas outflow passages 3 provided in the downward direction (longitudinal direction) toward the nozzle inner surface 5 to prevent Al 2 O 3 and the like from adhering to the nozzle inner surface 5. I have.
【0006】[0006]
【発明が解決しようとする課題】図6は図7に示された
従来型のノズル1を水銀槽内に浸漬して、該ノズル1の
ガス流出路からのガス流出状況を調査した結果を図中
(c)として示したもので、1mmの内径を有するノズ
ル1にガスプール2を設け、ノズル上・下方向に径0.
3mmの均一な貫通孔6を15個設けてガス流出路を形
成し、2.0kg/cm2 の圧力を有するArガスをガ
スプール2に供給し、各貫通孔6から噴出するガスによ
って生成するガス気泡個数を目視によりカウントし、そ
のノズル上・下方向のガス流出路の位置によって変化す
る状況を表したものである。図から明らかなように本例
においては上部No.1からNo.7までは下方に行く
に従い気泡発生個数が低減し、No.8以降の下方に属
する流出路からは気泡の発生はみられなかった。FIG. 6 is a graph showing the result of investigating the state of gas outflow from the gas outflow path of the nozzle 1 by immersing the conventional nozzle 1 shown in FIG. 7 in a mercury tank. The gas pool 2 is provided in a nozzle 1 having an inner diameter of 1 mm, and a diameter of 0.
Uniform through-holes 6 of 3 mm 15 pieces arranged to form a gas outflow passage, the Ar gas having a pressure of 2.0 kg / cm 2 was supplied to the gas pool 2, produced by gas ejected from the through holes 6 The number of gas bubbles is visually counted, and the number of gas bubbles changes depending on the position of the gas outflow path in the upward and downward directions of the nozzle. As is clear from FIG. No. 1 to No. Up to 7, the number of generated bubbles decreases as going downward. No air bubbles were generated from the outflow path belonging to the lower part after 8.
【0007】上記実験結果から判るように、同一径を有
する貫通孔6においては、ノズル上・下方向で気泡の発
生個数に差があり(ガス流出量に差ができ、その結果と
して気泡、発生個数の差として表れる)、均等にガスが
流出しないことが判明した。これは水銀のヘッド差に一
部起因すると思われる。As can be seen from the above experimental results, in the through-holes 6 having the same diameter, there is a difference in the number of generated bubbles in the upward and downward directions of the nozzle (a difference in the amount of gas flowing out, and as a result, It appears that the gas does not flow out evenly. This may be due in part to the head differences in mercury.
【0008】本発明はこのようなノズル上・下方向にお
いて、ガス流出量に差が生じないか、生じたとしてもそ
の差が少なくなるような新たなるノズルを開発したもの
で、できる限り上・下方向において均等なガス流出量を
確保することができるノズルを提供し、上記問題点の解
決を図ることを目的とするものである。The present invention has developed a new nozzle which does not cause a difference in the gas outflow amount in the upward and downward directions of the nozzle or reduces the difference even if it occurs. It is an object of the present invention to provide a nozzle capable of securing a uniform gas outflow amount in a downward direction, and to solve the above problems.
【0009】[0009]
【課題を解決するための手段】本発明の要旨とするとこ
ろは、下記手段を実施するところにある。 (1) 溶融金属を連続鋳造するに際しタンディッシュ
に装着するノズルにおいて、ノズル肉厚部内にガスプー
ルをノズル円周方向に配設すると共に、前記ガスプール
からノズル上・下方向にノズル内面へ向けてガス流出路
を設け、該ノズル上・下方向での流出路間のガス流量差
が少なくなるように構成せしめた連続鋳造用ノズル。 (2) 前記ガス流出路を貫通孔とし、該貫通孔をノズ
ル上・下方向で複数段にグループ分けし、グループ毎に
貫通孔断面積を等しくすると共に、上段側グループの貫
通孔断面積を小さくし、下段側グループに行くに従い順
次貫通孔断面積を大きくした(1)記載の連続鋳造用ノ
ズル。 (3) 前記ガス流出路の貫通孔断面積をノズル上・下
方向において、下部側に行くに従い順次大きくした
(1)記載の連続鋳造用ノズル。The gist of the present invention lies in the following means. (1) In a nozzle to be mounted on a tundish for continuous casting of molten metal, a gas pool is arranged in the nozzle circumferential direction in a thick portion of the nozzle, and the gas pool is directed upward and downward from the gas pool toward the inner surface of the nozzle. The continuous casting nozzle is provided with a gas outflow passage so as to reduce a gas flow difference between the outflow passages in the upper and lower directions of the nozzle. (2) The gas outflow passage is a through-hole, and the through-holes are divided into a plurality of stages in the upper and lower directions of the nozzle, and the cross-sectional areas of the through-holes are equalized for each group. (1) The continuous casting nozzle according to (1), wherein the nozzle is made smaller and the cross-sectional area of the through-hole is made larger in order toward the lower group. (3) The continuous casting nozzle according to (1), wherein the cross-sectional area of the through-hole of the gas outflow passage is gradually increased in the upper and lower directions of the nozzle toward the lower side.
【0010】(4) 前記ガス流出路の貫通孔断面を円
形に形成せしめた(2)または(3)記載の連続鋳造用
ノズル。 (5) (4)において、ガス流出路の各貫通孔径をノ
ズル上・下方向で貫通孔径を設定するに当たり、下記
(1)式に基づいて上から2段目以降の貫通孔径を求め
た連続鋳造用ノズル。 Φn=(K/(K−(n−1)ρgh)1/4 nφ1 ・・・・・(1) ただし、 Φn:上からn段目の貫通孔径(mm) K:定数 ρ:連続鋳造する金属比重(g/cm2 ) g:重力(g/cm2 ) h:貫通孔間隔(mm) nφ1:上から1段目の貫通孔径(mm)(4) The continuous casting nozzle according to (2) or (3), wherein a cross section of the through hole of the gas outflow passage is formed in a circular shape. (5) In (4), when setting the diameter of each through-hole of the gas outflow path in the upward and downward directions of the nozzle, the through-hole diameter of the second and subsequent through-holes from the top is determined based on the following equation (1). Nozzle for casting. Φn = (K / (K− (n−1) ρgh) 1/4 nφ1 (1) where Φn: diameter of through-hole at the nth stage from the top (mm) K: constant ρ: continuous casting Metal specific gravity (g / cm 2 ) g: Gravity (g / cm 2 ) h: Through hole interval (mm) nφ1: Diameter of first through hole (mm) from above
【0011】(6) 前記ガス流出路を気孔率の高いポ
ーラス耐火物で形成し、該ガス流出路をノズル上・下方
向で複数段にグループ分けし、グループ内でのポーラス
耐火物の気孔率を等しくすると共に、上段側グループの
気孔率を低くし、下段側グループに行くに従い順次気孔
率を高くした(1)記載の連続鋳造用ノズル。 (7) 前記ガス流出路を気孔率の高いポーラス耐火物
で形成し、該ガス流出路をノズル上・下方向で複数段に
グループ分けし、グループ内での流出路断面積を等しく
すると共に、上段側グループの流出路断面積を小さく
し、下段側グループに行くに従い順次流出路断面積を大
きくした(1)記載の連続鋳造用ノズル。 (8) 前記請求項6または請求項7において、各段の
グループ内での流通路断面積を上部から順次下部へ行く
に従い大きくした連続鋳造用ノズル。(6) The gas outflow passage is formed of a porous refractory having a high porosity, and the gas outflow passage is divided into a plurality of stages in the upper and lower directions of the nozzle, and the porosity of the porous refractory in the group is defined. (1), wherein the porosity of the upper group is reduced, and the porosity is sequentially increased toward the lower group. (7) The gas outflow passage is formed of a porous refractory having a high porosity, and the gas outflow passages are grouped into a plurality of stages in the upward and downward directions of the nozzle to make the outflow passage cross-sectional areas in the groups equal, The continuous casting nozzle according to (1), wherein the cross-sectional area of the outflow passage in the upper group is reduced, and the cross-sectional area of the outflow passage is gradually increased toward the lower group. (8) The continuous casting nozzle according to (6) or (7), wherein the cross-sectional area of the flow passage in the group of each stage is gradually increased from the top to the bottom.
【0012】(9) 前記ガス流出路をポーラス耐火物
で形成し、その断面積をノズル上・下方向で上部側の断
面積を小さく、順次下部側に行くに従い断面積を大きく
した(1)記載の連続鋳造用ノズル。 (10) 前記ガス流出路をノズルの上・下方向で2グ
ループに分割し、上段側グループを気孔率の高いポーラ
ス耐火物で形成し、下段側グループを貫通孔とした
(1)記載の連続鋳造用ノズル。 (11) (10)において、上段側グループのポーラ
ス耐火物の断面積を上方から順次下方に行くに従い大き
くし、かつ、下段側グループの貫通孔断面積を上方から
順次下方に行くに従い大きくした連続鋳造用ノズル。(9) The gas outflow passage is formed of a porous refractory, and the cross-sectional area of the cross-sectional area on the upper side in the upward and downward directions of the nozzle is reduced, and the cross-sectional area is sequentially increased toward the lower side. The nozzle for continuous casting as described. (10) The continuity according to (1), wherein the gas outflow passage is divided into two groups in the upper and lower directions of the nozzle, the upper group is formed of a porous refractory having a high porosity, and the lower group is a through hole. Nozzle for casting. (11) In (10), the cross section in which the cross-sectional area of the porous refractory of the upper group is gradually increased from top to bottom, and the cross-sectional area of the through-hole of the lower group is gradually increased from top to bottom. Nozzle for casting.
【0013】[0013]
【発明の実施の形態】本発明者らは前記課題の項で述べ
たように、ガス流出路断面積をノズル上・下方向で均一
にしたのでは、ガス流出路を通るガス量が等しくならな
いので、この解決策について種々検討を重ね、その結果
多くの実施形態を思い付くに至り本発明の開発に成功し
た。BEST MODE FOR CARRYING OUT THE INVENTION As described in the above section, the present inventors have made the gas outflow passage cross-sectional area uniform in the upward and downward directions of the nozzle, so that the gas amount passing through the gas outflow passage will not be equal. Therefore, various studies have been made on this solution, and as a result, many embodiments have been proposed, and the present invention has been successfully developed.
【0014】以下、本発明を図に基づいて説明する。図
1はガス流出路をノズル上・下方向で複数段にグループ
分けした例(本例では3グループ)で、ガス流出路を細
い貫通孔6とし各グループ毎にその貫通孔6の断面積
(垂直方向、以下同様)を等しくすると共に、上段側
(第1グループ)の貫通孔6aの断面積を小さく、下段
側(第2,第3グループ)に行くに従い順次貫通孔6
b,6cと断面積を大きくした場合について示した(ガ
ス流出路数は本例においては15個とした。以下同
様)。Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows an example in which gas outflow paths are grouped into a plurality of stages in the upper and lower directions of the nozzle (three groups in this example). The gas outflow paths are formed as thin through holes 6 and the cross-sectional area of the through holes 6 for each group ( The same applies to the vertical direction, the same applies hereinafter), the cross-sectional area of the through-hole 6a on the upper side (first group) is reduced, and the through-hole 6
The case where the cross-sectional area is increased to b and 6c is shown (the number of gas outflow paths is set to 15 in this example, and the same applies hereinafter).
【0015】図2はガス流出路を貫通孔6とし、ノズル
上・下方向で上方より下方に行くに従い徐々にその断面
積を増大していた例である。図3はガス流出路を気孔率
の高いポーラス耐火物7とし、ガス流出路をノズル上・
下方向でグループ分けし(本例では3グループ)、グル
ープ別にポーラス耐火物7の気孔率を異ならしめると共
に、上段側(第1グループ)の流出路ポーラス耐火物7
aの気孔率を低くし、下段側(第2,第3グループ)に
行くに従い順次気孔率を7b,7cと高くしていった例
を示したものである。この場合、ガス流出路をグループ
分けをせずにポーラス耐火物7の気孔率を同一とし、ノ
ズルの上方から下方に行くに従い順次ガス流出路を形成
するポーラス耐火物7の断面積を大きくしていくことに
より、上・下方向でガス流出量の均等化を図ることも可
能である。FIG. 2 shows an example in which the gas outflow path is formed as a through-hole 6 and its cross-sectional area gradually increases from the upper side to the lower side in the upward and downward directions of the nozzle. FIG. 3 shows that the gas outflow path is made of a porous refractory 7 having a high porosity, and the gas outflow path is located above the nozzle.
The porous refractory 7 is divided into groups in the downward direction (three groups in this example), and the porosity of the porous refractory 7 is made different for each group.
This is an example in which the porosity of a is lowered, and the porosity is sequentially increased to 7b and 7c toward the lower side (second and third groups). In this case, the porosity of the porous refractory 7 is made the same without grouping the gas outflow passages, and the cross-sectional area of the porous refractory 7 which sequentially forms the gas outflow passage from the upper part of the nozzle to the lower part is increased. By doing so, it is possible to equalize the gas outflow amount in the upward and downward directions.
【0016】さらに、図4はガス流出路をノズル上・下
方向で2グループに分割(必ずしも均等でなくともよ
い)し、上段側(第1グループ)を気孔率の高いポーラ
ス耐火物7で形成し、下段側(第2グループ)を貫通孔
6とした例である。このポーラス耐火物7と貫通孔6の
間でガス流出量に差を持たせないために上段のポーラス
耐火物7においては、大きな気孔率ものを採用するか、
ガス流出路断面積を大きくすることが考えられ、また、
ポーラス耐火物7および貫通孔6について夫々上方から
下方に行くに従い順次ガス流通路断面積を大きくすると
ガス流出量の均等化の効果が得られる。このような態様
も当然本発明に包含される。なお、ガス流出路を設ける
に際して、貫通孔6の場合はその断面形状は特に限定さ
れず、三角形、多角形、楕円形等種々の形状が考えられ
るが、ノズル製造上または強度上からは円形が適してい
る。Further, FIG. 4 shows that the gas outflow passage is divided into two groups in the upper and lower directions of the nozzle (not necessarily uniform), and the upper side (first group) is formed of a porous refractory 7 having a high porosity. In this example, the lower side (second group) is formed as a through hole 6. In order to prevent a difference in gas outflow amount between the porous refractory 7 and the through-hole 6, the porous refractory 7 in the upper stage should have a large porosity,
It is conceivable to increase the cross-sectional area of the gas outflow channel,
If the cross-sectional area of the gas flow passage is gradually increased from the upper side to the lower side for the porous refractory 7 and the through-hole 6, the effect of equalizing the gas outflow amount can be obtained. Such an embodiment is naturally included in the present invention. In providing the gas outflow passage, in the case of the through hole 6, the cross-sectional shape is not particularly limited, and various shapes such as a triangle, a polygon, and an ellipse can be considered. Are suitable.
【0017】前述のガス流通路の種々の形態について、
ノズル内面側より観視したときの状態を図5に示した。
同図(a)は図1に示したノズルのガス流通路を内面か
らの見たときの貫通孔6の様子を表したものであり、同
図(b)は図2に示したノズルについて同様に示した。
同図(c)は図3に示したポーラス耐火物7を流通路と
して用いた例で、上・下方向でグループ間で気孔率に差
(下方側が気孔率大)を持たしており、さらにガス流通
路断面積を上・下方向で差(下方に行くに従い大きくし
た)を付与した状況を示した。また、同図(d)は図4
に対応するものでガス流通路を上段はポーラス耐火物7
で形成し、下段は貫通孔6で形成した例であり、かつポ
ーラス耐火物7と貫通孔6において夫々上・下方向でそ
の断面積に差(下方に行くに従い大きくした)を持たせ
た。なお図7についての対応図は省略した。Regarding the various forms of the aforementioned gas flow passage,
FIG. 5 shows a state when viewed from the inner surface side of the nozzle.
2A shows the state of the through hole 6 when the gas flow passage of the nozzle shown in FIG. 1 is viewed from the inner surface, and FIG. 2B shows the same for the nozzle shown in FIG. It was shown to.
FIG. 3C shows an example in which the porous refractory 7 shown in FIG. 3 is used as a flow passage. The porosity differs between the groups in the upward and downward directions (the porosity is large on the lower side). This shows a situation in which the cross-sectional area of the gas flow passage is given a difference between the upper and lower directions (increased in the downward direction). FIG. 4D shows FIG.
The upper part of the gas passage is porous refractory 7
The lower stage is an example in which the through-hole 6 is formed, and the porous refractory 7 and the through-hole 6 have a difference in cross-sectional area in the upper and lower directions (increased as going downward). It should be noted that the corresponding diagram for FIG. 7 is omitted.
【0018】また、各々のガス貫通孔6の径(断面形状
は真円)をノズル上・下方向で夫々変えるに当たって上
から2段目以降の最適な貫通孔径を求める算出方法とし
て下記(1)式が推奨される。すなわち、 Φn=(K/(K−(n−1)ρgh)1/4 nφ1 ・・・・・(1) ただし、 Φn:上からn段目の貫通孔径(mm) K:定数 ρ:連続鋳造する金属比重(g/cm2 ) g:重力(g/cm2 ) h:貫通孔間隔(mm) nφ1:上から1段目の貫通孔径(mm) であり、上記式に従った貫通孔径を有するノズルにおい
ては、ノズル内面へ噴出するガス流量がノズル上・下方
向で均等に分配されるため、ノズルへの付着物の発生が
抑制される。In order to change the diameter of each gas through hole 6 (the cross-sectional shape is a perfect circle) in the upward and downward directions of the nozzle, the following method (1) is used to calculate the optimal through hole diameter of the second and subsequent stages from the top. Expressions are recommended. That is, Φn = (K / (K− (n−1) ρgh) 1/4 nφ1 (1) where Φn: Through-hole diameter (mm) at the nth stage from the top K: Constant ρ: Continuous The specific gravity of the metal to be cast (g / cm 2 ) g: gravity (g / cm 2 ) h: through-hole interval (mm) nφ1: diameter of the through-hole at the first step from the top (mm) In the nozzle having the nozzle, the flow rate of the gas ejected to the inner surface of the nozzle is evenly distributed in the upward and downward directions of the nozzle, so that the generation of deposits on the nozzle is suppressed.
【0019】前述の図6のうち本発明ノズルである図1
および図2におけるガス流出状況を図中それぞれ
(b),(a)として示したもので、1mmの内径を有
するノズルにガスプールを設け、ノズル上・下方向に1
5個の貫通孔をもってガス流出路を形成し、2.0kg
/cm2 のArガスをガスプールに供給し、各ガス流出
路から流出するガスによって生成するガス気泡個数を、
ノズル上・下方向のガス流出路の位置の相違によってそ
の発生個数の変化する状況を表したものである。なお、
ガス流出路としての貫通孔(断面真円)径をそのNo.
(最上方をNo.1とし最下方をNo.15とした)毎
に表1に示した。FIG. 1 showing the nozzle of the present invention out of FIG.
And (b) and (a), respectively, in FIG. 2 showing the gas outflow situation, wherein a gas pool is provided in a nozzle having an inner diameter of 1 mm, and 1
A gas outflow path is formed with five through holes, and 2.0 kg
/ Cm 2 is supplied to the gas pool, and the number of gas bubbles generated by the gas flowing out of each gas outflow path is calculated as follows:
This figure shows a situation in which the number of generated gas outlets changes depending on the position of the gas outflow passage in the upper and lower directions of the nozzle. In addition,
The diameter of the through-hole (perfect cross-section circle) as the gas outflow path was designated
(No. 1 at the top and No. 15 at the bottom) are shown in Table 1.
【0020】[0020]
【表1】 [Table 1]
【0021】図6から明らかなようにノズル上・下方向
でガス流出路を多段(本例では3段)にグループ分けし
た場合は、そのグループ内での上・下方向ではやはり上
・下間ではガス流出量に差異があり、気泡発生個数は下
方では少なくなっているが、従来のノズル(図7)での
ガス流出状況と比較すると明らかに改善されていること
が判る。As is apparent from FIG. 6, when the gas outflow paths are grouped into multiple stages (three stages in this example) in the upper and lower directions of the nozzle, the upper and lower directions in the group are also in the upper and lower directions. There is a difference in the gas outflow amount, and the number of generated bubbles is smaller in the lower part. However, it can be seen that it is clearly improved as compared with the gas outflow state in the conventional nozzle (FIG. 7).
【0022】また、ノズル上・下方向で各ガス流出路
(貫通孔6)を上方側から下方側に行くに従いガス流出
路断面積(貫通孔6の径)を徐々に増大していった場合
は、各貫通孔No.共にほぼ等しい気泡発生個数となっ
ており、各貫通孔6間での差異が少なく、均一なガス流
量が保たれていることが判る。上記例は全てタンディッ
シュの上ノズルについて示したが、下ノズルについても
同様のことが言える。また取鍋ノズルに適用しても当然
同様の効果が期待できる。さらにノズル内面に流出する
ガスについては、Arガスのみについて触れたが、溶鋼
に影響を及ぼさない不活性ガスは全て使用可能である。In the case where the cross-sectional area (diameter of the through-hole 6) of the gas outflow path (diameter of the through-hole 6) gradually increases from the upper side to the lower side of each gas outflow path (through hole 6) in the upward and downward directions of the nozzle. Indicates that each through-hole No. The numbers of generated bubbles are almost the same in both cases, and it can be seen that there is little difference between the through holes 6 and a uniform gas flow rate is maintained. Although the above examples all show the upper nozzle of the tundish, the same can be said for the lower nozzle. The same effect can be expected of course when applied to a ladle nozzle. Further, as for the gas flowing out to the inner surface of the nozzle, only the Ar gas is described, but any inert gas which does not affect the molten steel can be used.
【0023】[0023]
【発明の効果】本発明により溶鋼の注入において、ノズ
ル内面にAl2 O3 や地金の付着を回避することができ
る。また、ノズルの閉塞を引き起こすこともなく安定し
た鋳造作業が維持できるので、連々鋳においてもノズル
の事故による鋳造中断を防止することができると共に、
鋳造された鋳片も欠陥の少ない良好な品質を確保するこ
とができる等、生産性の向上にも寄与する効果大なるも
のがある。In the present invention the injection of the molten steel by, according to the present invention, it is possible to avoid the adhesion of as Al 2 O 3 or bullion to the nozzle inner surface. In addition, since a stable casting operation can be maintained without causing clogging of the nozzle, it is possible to prevent interruption of casting due to an accident of the nozzle even in continuous casting,
The cast slab also has a large effect that contributes to an improvement in productivity, for example, it can ensure good quality with few defects.
【図1】本発明ノズルの一例で、ガス流出路を貫通孔と
し、ノズル上・下方向でグループ分けした場合を示した
図FIG. 1 is a view showing an example of a nozzle according to the present invention, in which a gas outflow path is formed as a through hole, and the nozzles are grouped in an upward / downward direction.
【図2】本発明ノズルの他の例で、ガス流出路断面積を
ノズル上方から下方に行くに従い、徐々に大きくした場
合を示した図FIG. 2 is a view showing another example of the nozzle of the present invention, in which the cross-sectional area of the gas outflow passage is gradually increased from the upper side to the lower side of the nozzle.
【図3】本発明ノズルの他の例で、ガス流出路にポーラ
ス耐火物を用い、ノズル上・下方向でグループ分けした
場合を示した図FIG. 3 is a view showing another example of the nozzle according to the present invention, in which a porous refractory is used for a gas outflow path and the nozzles are grouped in upper and lower directions.
【図4】本発明ノズルの他の例で、ガス流出路を上段を
ポーラス耐火物とし、下段を貫通孔とした場合を示した
図FIG. 4 is a view showing another example of the nozzle of the present invention, in which the gas outflow passage is formed of a porous refractory in an upper stage and a through hole is formed in a lower stage.
【図5】本発明ノズルについて、ノズル内面からガス流
通路を観視した様子を示す図FIG. 5 is a diagram showing a state in which a gas flow passage is viewed from the inner surface of the nozzle of the nozzle of the present invention
【図6】本発明例ノズル及び従来ノズルでのガス流出路
でノズルの上・下方向での位置の差による気泡の発生状
況を示した図FIG. 6 is a view showing a state of generation of bubbles due to a difference in a position of a nozzle in a gas outflow path between the nozzle of the present invention and a conventional nozzle in the upper and lower directions.
【図7】従来のノズルにおけるガス流出路(貫通孔)で
のノズル上・下方向での状態を示した図FIG. 7 is a view showing a state of a gas outflow path (through hole) in a conventional nozzle in an upward and downward direction of the nozzle.
1 ノズル 2 ガスプール 4 ガス供給管 5 ノズル内面 6 貫通孔 7 ポーラス耐火物 Reference Signs List 1 nozzle 2 gas pool 4 gas supply pipe 5 nozzle inner surface 6 through hole 7 porous refractory
Claims (11)
ッシュに装着するノズルにおいて、ノズル肉厚部内にガ
スプールをノズル円周方向に配設すると共に、前記ガス
プールからノズル上・下方向にノズル内面へ向けてガス
流出路を設け、該ノズル上・下方向での流出路間のガス
流量差が少なくなるように構成せしめたことを特徴とす
る連続鋳造用ノズル。In a nozzle to be mounted on a tundish for continuous casting of molten metal, a gas pool is disposed in a nozzle circumferential direction in a thick portion of a nozzle, and a nozzle inner surface is formed from the gas pool upward and downward from the nozzle. A gas outflow passage toward the nozzle, and a difference in gas flow rate between the outflow passages in the upward and downward directions of the nozzle is reduced.
をノズル上・下方向で複数段にグループ分けし、グルー
プ毎に貫通孔断面積を等しくすると共に、上段側グルー
プの貫通孔断面積を小さくし、下段側グループに行くに
従い順次貫通孔断面積を大きくしたことを特徴とする請
求項1記載の連続鋳造用ノズル。2. The gas outflow passage is formed as a through-hole, and the through-hole is divided into a plurality of stages in the upward and downward directions of the nozzle so that the cross-sectional area of the through-hole is equal for each group. 2. The continuous casting nozzle according to claim 1, wherein the area is reduced and the cross-sectional area of the through-hole is gradually increased toward the lower group.
上・下方向において、下部側に行くに従い順次大きくし
たことを特徴とする請求項1記載の連続鋳造用ノズル。3. The continuous casting nozzle according to claim 1, wherein the cross-sectional area of the through-hole of the gas outflow passage is gradually increased in the upper and lower directions of the nozzle toward the lower side.
成せしめたことを特徴とする請求項2または請求項3記
載の連続鋳造用ノズル。4. The continuous casting nozzle according to claim 2, wherein a cross section of the gas outlet passage is formed in a circular shape.
孔径をノズル上・下方向で貫通孔径を設定するに当た
り、下記(1)式に基づいて上から2段目以降の貫通孔
径を求めたことを特徴とする連続鋳造用ノズル。 Φn=(K/(K−(n−1)ρgh)1/4 nφ1 ・・・・・(1) ただし、 Φn:上からn段目の貫通孔径(mm) K:定数 ρ:連続鋳造する金属比重(g/cm2 ) g:重力(g/cm2 ) h:貫通孔間隔(mm) nφ1:上から1段目の貫通孔径(mm)5. The method according to claim 4, wherein when setting the diameter of each through hole of the gas outflow passage in the upward and downward directions of the nozzle, the diameters of the through holes in the second and subsequent stages from the top are determined based on the following equation (1). Nozzle for continuous casting. Φn = (K / (K− (n−1) ρgh) 1/4 nφ1 (1) where Φn: diameter of through-hole at the nth stage from the top (mm) K: constant ρ: continuous casting Metal specific gravity (g / cm 2 ) g: Gravity (g / cm 2 ) h: Through hole interval (mm) nφ1: Diameter of first through hole (mm) from above
耐火物で形成し、該ガス流出路をノズル上・下方向で複
数段にグループ分けし、グループ内でのポーラス耐火物
の気孔率を等しくすると共に、上段側グループの気孔率
を低くし、下段側グループに行くに従い順次気孔率を高
くしたことを特徴とする請求項1記載の連続鋳造用ノズ
ル。6. The gas outflow passage is formed of a porous refractory having a high porosity, and the gas outflow passage is divided into a plurality of stages in the upper and lower directions of the nozzle, and the porosity of the porous refractory in the group is determined. 2. The continuous casting nozzle according to claim 1, wherein the porosity of the upper group is made lower, and the porosity is gradually increased toward the lower group.
耐火物で形成し、該ガス流出路をノズル上・下方向で複
数段にグループ分けし、グループ内での流出路断面積を
等しくすると共に、上段側グループの流出路断面積を小
さくし、下段側グループに行くに従い順次流出路断面積
を大きくしたことを特徴とする請求項1記載の連続鋳造
用ノズル。7. The gas outflow passage is formed of a porous refractory having a high porosity, and the gas outflow passages are divided into a plurality of stages in the upward and downward directions of the nozzles so that the cross-sectional areas of the outflow passages in the groups are equalized. 2. The continuous casting nozzle according to claim 1, wherein the cross-sectional area of the outflow passage in the upper group is reduced, and the cross-sectional area of the outflow passage is gradually increased toward the lower group.
各段のグループ内での流通路断面積を上部から順次下部
へ行くに従い大きくしたことを特徴とする連続鋳造用ノ
ズル。8. The method according to claim 6, wherein
A continuous casting nozzle characterized in that the cross-sectional area of the flow passage in each group of steps is gradually increased from the top to the bottom.
し、その断面積をノズル上・下方向で上部側の断面積を
小さく、順次下部側に行くに従い断面積を大きくしたこ
とを特徴とする請求項1記載の連続鋳造用ノズル。9. The gas outflow passage is formed of a porous refractory, and the cross-sectional area of the cross-sectional area in the upper and lower directions in the nozzle upper and lower directions is reduced, and the cross-sectional area is sequentially increased in the lower direction. The continuous casting nozzle according to claim 1.
で2グループに分割し、上段側グループを気孔率の高い
ポーラス耐火物で形成し、下段側グループを貫通孔とし
たことを特徴とする請求項1記載の連続鋳造用ノズル。10. The gas outlet path is divided into two groups in the upper and lower directions of the nozzle, the upper group is formed of a porous refractory having a high porosity, and the lower group is formed as a through hole. The continuous casting nozzle according to claim 1.
のポーラス耐火物の断面積を上方から順次下方に行くに
従い大きくし、かつ、下段側グループの貫通孔断面積を
上方から順次下方に行くに従い大きくしたことを特徴と
する連続鋳造用ノズル。11. The cross-sectional area of the porous refractory of the upper group is gradually increased from the top to the bottom, and the cross-sectional area of the through-hole of the lower group is gradually increased from the top to the bottom. A continuous casting nozzle characterized by the following.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13419998A JPH11314142A (en) | 1998-04-30 | 1998-04-30 | Nozzle for continuous casting |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13419998A JPH11314142A (en) | 1998-04-30 | 1998-04-30 | Nozzle for continuous casting |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH11314142A true JPH11314142A (en) | 1999-11-16 |
Family
ID=15122756
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP13419998A Pending JPH11314142A (en) | 1998-04-30 | 1998-04-30 | Nozzle for continuous casting |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH11314142A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20020052614A (en) * | 2000-12-26 | 2002-07-04 | 이구택 | Device for uniformly supplying the inert gas of upper nozzle |
US7575135B2 (en) | 2002-01-28 | 2009-08-18 | Jfe Steel Corporation | Immersion nozzle for continuous casting of steel and method of continuous casting method of steel |
JP2013184199A (en) * | 2012-03-08 | 2013-09-19 | Kurosaki Harima Corp | Nozzle with gas injection function |
JP2013220469A (en) * | 2012-04-19 | 2013-10-28 | Nippon Steel & Sumitomo Metal Corp | Nozzle for teeming |
JP2015016499A (en) * | 2013-07-12 | 2015-01-29 | Jfeスチール株式会社 | Continuous casting method of steel |
JP2020108903A (en) * | 2019-01-07 | 2020-07-16 | 日本製鉄株式会社 | Tundish upper nozzle |
-
1998
- 1998-04-30 JP JP13419998A patent/JPH11314142A/en active Pending
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR20020052614A (en) * | 2000-12-26 | 2002-07-04 | 이구택 | Device for uniformly supplying the inert gas of upper nozzle |
US7575135B2 (en) | 2002-01-28 | 2009-08-18 | Jfe Steel Corporation | Immersion nozzle for continuous casting of steel and method of continuous casting method of steel |
JP2013184199A (en) * | 2012-03-08 | 2013-09-19 | Kurosaki Harima Corp | Nozzle with gas injection function |
JP2013220469A (en) * | 2012-04-19 | 2013-10-28 | Nippon Steel & Sumitomo Metal Corp | Nozzle for teeming |
JP2015016499A (en) * | 2013-07-12 | 2015-01-29 | Jfeスチール株式会社 | Continuous casting method of steel |
JP2020108903A (en) * | 2019-01-07 | 2020-07-16 | 日本製鉄株式会社 | Tundish upper nozzle |
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