JPH07214252A - Method for continuous casting of clean steel - Google Patents
Method for continuous casting of clean steelInfo
- Publication number
- JPH07214252A JPH07214252A JP2348694A JP2348694A JPH07214252A JP H07214252 A JPH07214252 A JP H07214252A JP 2348694 A JP2348694 A JP 2348694A JP 2348694 A JP2348694 A JP 2348694A JP H07214252 A JPH07214252 A JP H07214252A
- Authority
- JP
- Japan
- Prior art keywords
- ladle
- tundish
- molten steel
- long nozzle
- 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]
【産業上の利用分野】本発明は、連続鋳造鋳片内のチャ
ージとチャージの鍋交換にともない、通常タンディッシ
ュ内にて起こる、スラグの巻き込み、たたき込みを防止
し、非金属介在物をモールドに流出させることなく、鋳
造する技術に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention prevents slag entrapment and tapping, which normally occur in a tundish, when a charge in a continuously cast slab and a pan for the charge are exchanged, and a non-metallic inclusion is molded. It relates to a technique for casting without spillage.
【0002】[0002]
【従来の技術】鉄鋼製造業における溶鋼清浄化の要望は
強く、単にC、P、S等の不純物元素の低減にとどまら
ず、転炉、二次精錬工程、連続鋳造工程における脱酸生
成物、精錬材、耐火物、保温材、パウダーに起因する非
金属介在物を極力取り除いた高清浄度の鋼片の製造が求
められている。2. Description of the Related Art There is a strong demand for molten steel cleaning in the steel manufacturing industry, and it is not limited to the reduction of impurity elements such as C, P and S, but also deoxidation products in converters, secondary refining processes and continuous casting processes. It is required to manufacture highly clean steel slabs by removing refining materials, refractory materials, heat insulating materials, and non-metallic inclusions caused by powders as much as possible.
【0003】製品の表面欠陥及び内部欠陥発生原因とな
る非金属介在物は特に、連続鋳造のチャージとチャージ
の継目部分において、タンディッシュスラグの懸濁によ
り、顕著に増加することが知られている。It is known that non-metallic inclusions which cause surface defects and internal defects of products are remarkably increased due to suspension of tundish slag, particularly at the charge and the joint portion of the charge in continuous casting. .
【0004】従来からの鋼の連続鋳造における取鍋〜タ
ンディッシュへの溶鋼注入は図1に示すごとく取鍋1の
底部に装着されたスライディングノズル2の開度を調整
しつつ、当該ノズル2の下部に位置するロングノズル3
の先端部をタンディッシュ内溶鋼4に浸漬させた状態で
行っている。In the conventional continuous casting of steel, the molten steel is poured from the ladle to the tundish by adjusting the opening of the sliding nozzle 2 mounted on the bottom of the ladle 1 as shown in FIG. Long nozzle 3 located at the bottom
It is performed in a state in which the tip portion of is immersed in the molten steel 4 in the tundish.
【0005】しかしながら、前鍋の注入終了後、後鍋の
溶鋼をロングノズル3を用いて注入するが、後鍋の注入
開始時にタンディッシュ内溶鋼4の表面に浮遊している
スラグ層5が、ロングノズル3よりの注入流9によって
タンディッシュ内溶鋼4の内部へまき込み、あるいは、
たたき込まれる。However, after the pouring of the front ladle is finished, the molten steel of the rear ladle is poured using the long nozzle 3, but at the start of the pouring of the rear ladle, the slag layer 5 floating on the surface of the molten steel 4 in the tundish is Injected into the molten steel 4 in the tundish by the injection flow 9 from the long nozzle 3, or
It is knocked in.
【0006】タンディッシュ容量、鋳造速度等によって
も異なるが、タンディッシュ内溶鋼4の内部へたたき込
まれたスラグの内、大型でほぼ100μm以上の粒径を
有するものは再浮上するものの、100μm以下のもの
は溶鋼流とともにモールド内に注入され、鋳片内非金属
介在物となって、鍋交換部位(継目部)鋳片の著しい品
質悪化を起こす原因となっていた。Although it depends on the tundish capacity, casting speed, etc., among the slags poured into the molten steel 4 in the tundish, the large slags having a grain size of approximately 100 μm or more re-float, but 100 μm or less. The molten steel was poured into the mold together with the molten steel flow and became non-metallic inclusions in the cast, causing the remarkable deterioration of the quality of the pot replacement part (seam part) cast.
【0007】[0007]
【発明が解決しようとする課題】そこで、本発明者らが
実験、研究を続けた結果、鍋交換時に継目部の鋳片の品
質悪化をもたらす原因は以下の点にあることがわかっ
た。Then, as a result of the experiments and researches conducted by the present inventors, it was found that the cause of the deterioration of the quality of the slab at the seam at the time of pan replacement is as follows.
【0008】鍋交換から後鍋溶鋼注入開始までに1〜2
分の準備時間を要するため、通常鋳造を継続すれば必然
的にタンディッシュ内溶鋼4量が低下する。1 to 2 from the time the pan is changed until the time when the molten steel is poured into the rear pan
Since preparation time is required, the amount of molten steel 4 in the tundish inevitably decreases if normal casting is continued.
【0009】従って、後鍋のスライディングノズルを全
開にし、ロングノズルを通して、タンディッシュに溶鋼
を供給する際に、ロングノズルから吐出する溶鋼流によ
って、タンディッシュ溶鋼上に浮遊するスラグが、溶鋼
中にたたき込み、あるいは、まきこまれ、懸濁した汚い
溶鋼がモールド内に流入する。このために鍋交換部位鋳
片の品質が悪化する。Therefore, when the sliding nozzle of the rear pan is fully opened and the molten steel is supplied to the tundish through the long nozzle, the slag floating on the tundish molten steel is generated in the molten steel by the molten steel flow discharged from the long nozzle. Dirty molten steel that has been knocked in or thrown in and is suspended flows into the mold. This deteriorates the quality of the slab for pot replacement.
【0010】従って、従来、継目部鋳片は、品質厳格機
には適用できずに、屑化などして、歩留まりを悪化させ
ていた。Therefore, hitherto, the seam slab cannot be applied to a strict quality machine, and the yield is deteriorated by scrapping.
【0011】しかしながら、本発明者らが実験、研究を
続けた結果、鍋注入スタート時のロングノズルの浸漬深
さと注入速度を規定することによって、継目部の溶鋼の
清浄化を可能とし、継目部鋳片の品質劣化を防止できる
ことがわかった。However, as a result of the experiments and researches conducted by the present inventors, it was possible to clean the molten steel at the seam by defining the immersion depth and the pouring speed of the long nozzle at the start of pouring the pan. It was found that the quality deterioration of the slab can be prevented.
【0012】[0012]
【課題を解決するための手段】従って、本発明は厳格化
した高清浄度鋼製造の要求を満足するための清浄鋼を得
るための方法を提供するもので、その要旨とするところ
は以下の通りである。SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for obtaining clean steel for satisfying the strict requirements for manufacturing high cleanliness steel, and the gist thereof is as follows. On the street.
【0013】取鍋からタンディッシュに溶鋼を注入する
方法として、ロングノズルを用いる場合の連続鋳造方法
において、前鍋に引き続き後鍋溶鋼をタンディッシュに
供給するにあたり、後鍋注入スタート時のロングノズル
の浸漬深さが50mm以上で、且つ、ロングノズルから
の注入速度が定常状態時の2.5倍以下であることを特
徴とする清浄鋼の連続鋳造方法。As a method for injecting molten steel from a ladle into a tundish, in a continuous casting method in which a long nozzle is used, a long nozzle at the start of injecting a rear ladle is used to supply molten steel to the tundish after the front ladle. The continuous casting method for clean steel is characterized in that the immersion depth is 50 mm or more, and the injection speed from the long nozzle is 2.5 times or less than that in a steady state.
【0014】以下に本発明の詳細を実施例に基づいて説
明する。The details of the present invention will be described below based on examples.
【0015】図2は継ぎ目部介在物に対する鍋スタート
時におけるロングノズル浸漬深さの影響を示したもので
ある。FIG. 2 shows the effect of the long nozzle immersion depth on the seam inclusions at the start of the pan.
【0016】横軸はロングノズル浸漬深さ、縦軸は鍋ス
タート時の継目位置前後3m内の介在物個数である。こ
こで、注入速度は、10t/minである。The horizontal axis represents the long nozzle immersion depth, and the vertical axis represents the number of inclusions within 3 m before and after the seam position at the start of the pan. Here, the injection rate is 10 t / min.
【0017】図2よりロングノズル浸漬深さが増すほ
ど、介在物の個数は減少しているが、これは、タンディ
ッシュ内スラグの巻き込みが防止されるためであり、浸
漬深さが50mm以上では、介在物レベルが、ミドル鋳
片並であった。As shown in FIG. 2, as the long nozzle immersion depth increases, the number of inclusions decreases. This is because the inclusion of slag in the tundish is prevented, and when the immersion depth is 50 mm or more. The inclusion level was comparable to that of a middle slab.
【0018】このことより、継目部清浄化に必要なロン
グノズル浸漬深さは50mm以上である。As a result, the long nozzle immersion depth required for cleaning the seam is 50 mm or more.
【0019】図3は、継ぎ目部介在物に対する鍋注入速
度の影響を示したものである。横軸は鍋スタート時のモ
ールド湯面位置基準の鋳造長、縦軸は、介在物の個数で
あり、○は鍋注入速度16t/min、●は鍋注入速度
10t/minの結果である。両者ともロングノズル浸
漬深さを50mmに固定した条件である。FIG. 3 shows the effect of the pot pouring speed on the seam inclusions. The horizontal axis is the casting length based on the position of the mold surface at the start of the pan, the vertical axis is the number of inclusions, ◯ is the pot pouring speed of 16 t / min, and ● is the pot pouring speed of 10 t / min. In both cases, the long nozzle immersion depth is fixed to 50 mm.
【0020】図3より鍋注入速度が小さくなるほど介在
物個数は減少しており、これはロングノズルの吐出流
が、おさえられることによりタンディッシュ内スラグの
巻き込みが防止されたことによる。As shown in FIG. 3, the smaller the pouring speed of the pan, the smaller the number of inclusions. This is because the discharge flow of the long nozzle was suppressed and the inclusion of slag in the tundish was prevented.
【0021】尚、4t/minの注入速度で注入した場
合も、10t/minで注入時の介在物レベル並、ある
いは、それよりも良い結果が、得られた。Even when the injection rate was 4 t / min, the level of inclusions at the time of injection was 10 t / min, or a better result was obtained.
【0022】以上より、継目部清浄化に必要な鍋注入速
度は10t/min以下である。From the above, the pot pouring speed required for cleaning the seam is 10 t / min or less.
【0023】[0023]
【発明の効果】上記のように、本発明の適用により、鍋
交換時の継目部鋳片の介在物レベルが、ミドル鋳片並ま
で向上し、屑化することなく、予定規格への適用が可能
となり、歩留向上に寄与することができた。As described above, by applying the present invention, the level of inclusions in the seam slab at the time of pan replacement is improved to the level of a middle slab, and it is possible to apply it to a planned standard without scrapping. It became possible and it was possible to contribute to the improvement of the yield.
【図1】ロングノズルを通してタンディッシュに溶鋼を
供給している状態を表す図。FIG. 1 is a diagram showing a state in which molten steel is being supplied to a tundish through a long nozzle.
【図2】介在物レベルに対するロングノズルの浸漬深さ
の影響を示す図。FIG. 2 is a diagram showing the influence of the immersion depth of a long nozzle on the level of inclusions.
【図3】介在物レベルに対するロングノズルからの溶鋼
の注入速度の影響を示す図。FIG. 3 is a diagram showing the effect of the injection rate of molten steel from a long nozzle on the level of inclusions.
1 取鍋 2 スライディングノズル 3 ロングノズル 4 溶鋼 5 スラグ層 9 注入流 1 Ladle 2 Sliding nozzle 3 Long nozzle 4 Molten steel 5 Slag layer 9 Injection flow
Claims (1)
る方法として、ロングノズルを用いる場合の連続鋳造方
法において、前鍋に引き続き後鍋溶鋼をタンディッシュ
に供給するにあたり、後鍋注入スタート時のロングノズ
ルの浸漬深さが50mm以上で、且つ、ロングノズルか
らの注入速度が定常状態時の2.5倍以下であることを
特徴とする清浄鋼の連続鋳造方法。1. A method for injecting molten steel from a ladle into a tundish, in a continuous casting method using a long nozzle, in order to continuously supply molten metal to the tundish in a front ladle after starting the pouring of a rear ladle. A continuous casting method for clean steel, characterized in that the immersion depth of the long nozzle is 50 mm or more, and the injection speed from the long nozzle is 2.5 times or less than that in a steady state.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2348694A JPH07214252A (en) | 1994-01-26 | 1994-01-26 | Method for continuous casting of clean steel |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2348694A JPH07214252A (en) | 1994-01-26 | 1994-01-26 | Method for continuous casting of clean steel |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH07214252A true JPH07214252A (en) | 1995-08-15 |
Family
ID=12111860
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2348694A Pending JPH07214252A (en) | 1994-01-26 | 1994-01-26 | Method for continuous casting of clean steel |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH07214252A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106541122A (en) * | 2015-09-17 | 2017-03-29 | 鞍钢股份有限公司 | A kind of method for preventing tundish slag |
-
1994
- 1994-01-26 JP JP2348694A patent/JPH07214252A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN106541122A (en) * | 2015-09-17 | 2017-03-29 | 鞍钢股份有限公司 | A kind of method for preventing tundish slag |
CN106541122B (en) * | 2015-09-17 | 2018-06-26 | 鞍钢股份有限公司 | A kind of method for preventing tundish slag |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20020403 |