JPS6358665B2 - - Google Patents
Info
- Publication number
- JPS6358665B2 JPS6358665B2 JP27629285A JP27629285A JPS6358665B2 JP S6358665 B2 JPS6358665 B2 JP S6358665B2 JP 27629285 A JP27629285 A JP 27629285A JP 27629285 A JP27629285 A JP 27629285A JP S6358665 B2 JPS6358665 B2 JP S6358665B2
- Authority
- JP
- Japan
- Prior art keywords
- nozzle
- molten steel
- cal
- flow
- slab
- 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 34
- 239000010959 steel Substances 0.000 claims description 34
- 238000007654 immersion Methods 0.000 claims description 13
- 238000005266 casting Methods 0.000 claims description 12
- 238000009749 continuous casting Methods 0.000 claims description 10
- 238000000034 method Methods 0.000 claims description 6
- 230000000630 rising effect Effects 0.000 claims description 3
- 230000005499 meniscus Effects 0.000 claims description 2
- 239000000843 powder Substances 0.000 description 20
- 238000010586 diagram Methods 0.000 description 8
- 230000007547 defect Effects 0.000 description 4
- 230000001050 lubricating effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000005856 abnormality Effects 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 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
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は介在物の少ない高清浄鋼を、パウダー
巻き込み、デイツケル発生等の操業トラブルなく
安定に製造するための連続鋳造方法に関するもの
である。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a continuous casting method for stably producing highly clean steel with few inclusions without operational troubles such as powder entrainment and Deitzkel generation.
鋼の連続鋳造においては、タンデイツシユから
ノズルを介して鋳型へ溶鋼を注入し、鋳型で急冷
し、凝固した鋼を連続的に引き抜き、所定寸法に
切断し、鋳片を得る。
In continuous steel casting, molten steel is injected from a tundish into a mold through a nozzle, rapidly cooled in the mold, and the solidified steel is continuously drawn out and cut into predetermined dimensions to obtain slabs.
かかる際に、従来は実開昭47−37910号公報に
示されるようなＹ型２孔の浸漬ノズルを使用して
いた。該ノズルを使用した場合には第３図に示す
ような鋳型内溶鋼流動が形成され、該溶鋼流動が
パウダー巻き込みやデツケル発生などの鋳片の品
質および操業の安定性に多大の影響を与えること
は周知である（たとえば鉄と鋼（1981）、S849）。 In this case, conventionally, a Y-shaped two-hole immersion nozzle as shown in Japanese Utility Model Application Publication No. 47-37910 has been used. When this nozzle is used, the molten steel flow in the mold as shown in Figure 3 is formed, and this molten steel flow has a great effect on the quality of the slab and the stability of operation, such as powder entrainment and descaling. is well known (e.g. Tetsu to Hagane (1981), S849).
つまり、Ｙ型浸漬ノズルを使用した場合の鋳型
溶鋼流動パターンでは、ノズル吐出孔より噴出さ
れた溶鋼流は短辺側凝固シエルを直撃した後に上
昇流と下降流に分岐する。上昇流が大きすぎる場
合には溶鋼湯面上に投入している溶融パウダーを
巻き込み、介在物系欠陥を形成せしめ、鋳片の品
質劣化を招く。逆に上昇流が小さすぎる場合に
は、溶融パウダーと溶鋼湯面への熱量供給が不充
分となり、パウダーの溶融不足を引き起こした
り、溶鋼湯面近傍に「デイツケル」と称する地金
を形成し、品質劣化および操業不安定を招く。 That is, in the mold molten steel flow pattern when a Y-type immersion nozzle is used, the molten steel flow jetted from the nozzle discharge hole directly hits the short side solidification shell and then branches into an upward flow and a downward flow. If the upward flow is too large, it will entrain the molten powder that has been thrown onto the surface of the molten steel, forming inclusion-based defects and deteriorating the quality of the slab. On the other hand, if the upward flow is too small, the supply of heat to the molten powder and the molten steel surface will be insufficient, causing insufficient melting of the powder, or forming a base metal called "Deitskell" near the molten steel surface. This leads to quality deterioration and operational instability.
上昇流の強さが鋳造するスラブ幅や鋳造速度以
外に、浸漬ノズルの吐出口径や吐出角度に依存す
ることは、今までの操業経験上大まかな傾向が知
られているに過ぎない。従つて、今まではある操
業条件に適する浸漬ノズル形状を見い出すために
は、種々の形状の浸漬ノズルを製作し、これらの
ノズルを一つ一つ実湯で試験し、操業および品質
を評価しながら試行錯誤で選定していたため、ノ
ズルの最適形状を決定するのが非効率的で無駄が
多く、かつ操業上もブレークアウト等の非常に危
険な事態を引き起こすこともあつた。 The fact that the strength of the upward flow depends not only on the width of the slab to be cast and the casting speed but also on the discharge opening diameter and discharge angle of the submerged nozzle is only a general trend known from past operational experience. Therefore, until now, in order to find a submerged nozzle shape that is suitable for certain operating conditions, it has been necessary to manufacture submerged nozzles of various shapes, test each of these nozzles one by one with actual hot water, and evaluate the operation and quality. However, because the selection was made through trial and error, determining the optimal nozzle shape was inefficient and wasteful, and could also lead to extremely dangerous operational situations such as breakouts.
本発明は、連続鋳造において、製造する鋳片
幅、鋳片厚および鋳造速度に適合し、パウダー巻
き込みがなく、かつデイツケルの発生を防止でき
る浸漬ノズルの最適形状を決定し、該浸漬ノズル
を使用することにより高清浄鋼を安定して製造す
ることができる連続鋳造方法を提供することを目
的とする。
In continuous casting, the present invention determines the optimal shape of a submerged nozzle that is compatible with the width of the slab to be produced, the thickness of the slab, and the casting speed, and that prevents powder entrainment and generation of Deitzkel, and uses the submerged nozzle. The purpose of the present invention is to provide a continuous casting method that can stably produce highly clean steel.
本発明は、鋳型内溶鋼のほぼ中央に上部よりノ
ズル吐出角θ（deg）、ノズル径ｄ（mm）の２孔浸
漬ノズルを浸漬し、該ノズルより溶鋼を吐出して
連続鋳造するに際し、短片メニスカス部位の溶鋼
上昇流速ｕ（ｍ／ｓ）を
0.033≦ｕ≦0.037（１＋1000／Ａ）
とすることを特徴とする連続鋳造方法である。
In the present invention, a two-hole immersion nozzle with a nozzle discharge angle θ (deg) and a nozzle diameter d (mm) is immersed from above almost in the center of the molten steel in the mold, and when continuously casting the molten steel by discharging the molten steel from the nozzle. This continuous casting method is characterized in that the rising flow velocity u (m/s) of molten steel at the meniscus portion satisfies 0.033≦u≦0.037 (1+1000/A).
但し、流速ｕは次式により求める計算値であ
る。 However, the flow velocity u is a calculated value obtained from the following equation.
Lo＋ｘ／ｄ≦36.5の場合
ｕ＝6.3dVCAL／（Lo＋ｘ）（１−sinθ／２）
Lo＋ｘ／ｄ＞36.5の場合
ｕ＝230d2VCAL／（Lo＋ｘ）2（１−sinθ／２）
VCAL＝2AB Vc／（60πd2）
Lo＝Ａ／2cosθ，ｘ＝Atamθ／２＋x0
ここで、ｄはノズル吐出口径（mm）、θはノズ
ル吐出角（deg）、Ａはスラブ幅（mm）、Ｂはスラ
ブ厚（mm）、Vcは鋳造速度（ｍ／min）、VCALは
平均吐出流速（ｍ／ｓ）、x0は浸漬深さ（mm）で
ある。When Lo+x/d≦36.5 u=6.3dV CAL /(Lo+x)(1-sinθ/2) When Lo+x/d>36.5 u=230d 2 V CAL /(Lo+x) 2 (1-sinθ/2) V CAL =2AB Vc/(60πd 2 ) Lo=A/2cosθ, x=Atamθ/2+x 0where , d is nozzle discharge opening diameter (mm), θ is nozzle discharge angle (deg), A is slab width (mm), B is the slab thickness (mm), Vc is the casting speed (m/min), V CAL is the average discharge flow rate (m/s), and x 0 is the immersion depth (mm).
以下に本発明の作用について詳細に説明する。 The operation of the present invention will be explained in detail below.
第１図は本発明の内容を説明する模式図、第２
図は本発明の適正域を示す説明図、第３図は連鋳
鋳型内の溶鋼流動を示す説明図である。１は浸漬
ノズル、２は鋳型、３は潤滑用パウダー、４は上
昇流、５は巻き込まれたパウダー、６は溶鋼湯面
上に形成したデイツケルを示す。 Figure 1 is a schematic diagram explaining the content of the present invention, Figure 2 is a schematic diagram explaining the content of the present invention.
The figure is an explanatory diagram showing the appropriate range of the present invention, and FIG. 3 is an explanatory diagram showing the flow of molten steel in a continuous casting mold. 1 is an immersion nozzle, 2 is a mold, 3 is a lubricating powder, 4 is an upward flow, 5 is a rolled-up powder, and 6 is a Deitzkel formed on the surface of molten steel.
従来の連続鋳造工程は、第３図に示すように溶
鋼が浸漬ノズル１を介して鋳型２内へ導かれる
が、かかる際実開昭47−37910号公報に示される
ようなＹ型２孔の浸漬ノズルを使用することが一
般である。Ｙ型２孔の浸漬ノズルを使用した場合
の鋳型内溶鋼流動は、第３図ａに示すように、ノ
ズル吐出孔より噴出された溶鋼流は短辺側凝固シ
エルに直撃した後に、上昇流４と下降流とに分岐
する。高速鋳造時には、ノズル吐出流速が大きく
なるに従い上昇流４の流速も大きくなるため、第
３図ｂに示すように、上昇流４によつて溶鋼湯面
上に存在する潤滑用パウダー３が溶鋼中へ巻き込
まれる。このようにして巻き込まれたパウダー５
は溶鋼流動により鋳片内部に深く浸入し、介在物
欠陥となる。 In the conventional continuous casting process, as shown in Fig. 3, molten steel is introduced into a mold 2 through an immersion nozzle 1, but in this case, a Y-shaped two-hole type casting method is used, as shown in Japanese Utility Model Application Publication No. 47-37910. It is common to use submerged nozzles. The flow of molten steel in the mold when a Y-shaped two-hole immersion nozzle is used is as shown in Figure 3a. After the molten steel flow ejected from the nozzle discharge hole directly hits the solidified shell on the short side, it becomes an upward flow 4. and a downward flow. During high-speed casting, as the nozzle discharge flow rate increases, the flow rate of the upward flow 4 also increases, so as shown in Fig. 3b, the lubricating powder 3 present on the surface of the molten steel is moved into the molten steel by the upward flow 4. get caught up in Powder 5 caught in this way
Penetrates deeply into the slab due to the flow of molten steel, resulting in inclusion defects.
従つて、この上昇流によるパウダーの巻き込み
を回避する目的で上昇流を弱めるため、吐出口径
を大きくしたり、吐出角度を下向に大きくするこ
とが一般的な対策であるが、この効果が大き過
ぎ、上昇流が弱くなりすぎると、第３図ｃに示す
ように溶鋼湯面上への熱量供給が不足して潤滑用
パウダーの溶融が不充分になり、パウダー本来の
機能を果さず、鋳片引抜き力が急増し、甚しい場
合にはブレークアウト等の操業トラブルを引き起
こす。また、パウダーと溶鋼の界面にデイツケル
と称する凝固鉄塊を形成し、品質および操業の異
常を招く。 Therefore, in order to avoid the entrainment of powder by this upward flow, common countermeasures are to increase the diameter of the discharge port or to increase the downward angle of the discharge in order to weaken the upward flow, but this is not very effective. If the rising flow becomes too weak, the supply of heat to the surface of the molten steel will be insufficient, as shown in Figure 3c, and the lubricating powder will not be sufficiently melted, and the powder will not perform its original function. The force for pulling out the slab increases rapidly, and in severe cases, it causes operational troubles such as breakouts. In addition, a solidified iron lump called Deitzkel is formed at the interface between the powder and molten steel, leading to quality and operational abnormalities.
以上の知見より、ある鋳造条件に対してパウダ
ー巻き込みもデイツケル発生も防止して第３図ａ
に示すような適正な溶鋼流動を得るには、上昇流
がある限定された範囲内に維持されるような形状
を有する浸漬ノズルを使用することが重要であ
る。 Based on the above knowledge, it is possible to prevent powder entrainment and Deitzkel generation under certain casting conditions as shown in Figure 3a.
In order to obtain proper molten steel flow as shown in Figure 1, it is important to use a submerged nozzle with a geometry that maintains the upward flow within a certain limited range.
本発明者らは第１図に示すようなモデルを考
え、上昇流の強弱を示すパラメーターとして次式
で計算されるｕ値を考えた。 The present inventors considered a model as shown in FIG. 1, and considered the u value calculated by the following equation as a parameter indicating the strength of the upward flow.
Lo＋ｘ／ｄ≦36.5の場合
ｕ＝6.3dVCAL／Lo＋ｘ（１−sinθ／２）
Lo＋ｘ／ｄ＞36.5の場合
ｕ＝230d2VCAL／（Lo＋ｘ）2（１−sinθ／２）
VCAL＝2AB Vc／（60πd2）
Lo＝Ａ／2cosθ，ｘ＝Atamθ／２＋x0
ただし、ｄはノズル吐出口径（mm）、θはノズ
ル吐出角（deg）、Ａはスラブ幅（mm）、Ｂはスラ
ブ厚（mm）、Vcは鋳造速度（ｍ／min）、VCALは
平均吐出流速（ｍ／ｓ）、x0は浸漬深さ（mm）で
ある。When Lo+x/d≦36.5 u=6.3dV CAL /Lo+x (1-sinθ/2) When Lo+x/d>36.5 u=230d 2 V CAL /(Lo+x) 2 (1-sinθ/2) V CAL =2AB Vc/(60πd 2 ) Lo=A/2cosθ, x=Atamθ/2+x 0 However, d is the nozzle discharge opening diameter (mm), θ is the nozzle discharge angle (deg), A is the slab width (mm), and B is the slab thickness. (mm), Vc is the casting speed (m/min), V CAL is the average discharge flow rate (m/s), and x 0 is the immersion depth (mm).
さらに、種々の実験データより、パウダー巻き
込みとデイツケル発生の両者を防止できるｕ値の
適正域は、第２図に示すように、
0.033≦ｕ≦0.037（１＋1000／Ａ）
であることを知得した。これを指針として、介在
物レベルの低い清浄鋼を安定した状態で連続鋳造
することが可能となつた。 Furthermore, from various experimental data, we learned that the appropriate range of u value that can prevent both powder entrainment and Deitzkel generation is 0.033≦u≦0.037 (1+1000/A), as shown in Figure 2. . Using this as a guideline, it has become possible to continuously cast clean steel with a low inclusion level in a stable state.
鋳片幅1600mm、鋳片厚245mmの鋳片を鋳造速度
1.85m／minで鋳造する連続鋳造の場合、ｕ値の
適正値は次のようになる。
Casting speed of slab with slab width 1600mm and slab thickness 245mm
In the case of continuous casting at 1.85 m/min, the appropriate value for the u value is as follows.
0.033≦ｕ≦0.060
ｕ値がこの適正値を満足するための浸漬ノズル
として、吐出口径ｄ＝70mmφ、吐出角度θ＝45゜
の形状を選定した場合、ｕ値は0.0476となり、上
記の条件式を満足する。この浸漬ノズルを使用し
て鋳造したところ、パウダー巻き込みおよびデイ
ツケルを発生せず、介在物系欠陥の少ない高清浄
鋼を安定して製造することが出来た。 0.033≦u≦0.060 If a shape with a discharge opening diameter d = 70 mmφ and a discharge angle θ = 45° is selected as an immersion nozzle in order for the u value to satisfy this appropriate value, the u value will be 0.0476, and the above conditional expression can be be satisfied. When this immersion nozzle was used for casting, it was possible to stably produce highly clean steel without powder entrainment or Deitzkel, and with few inclusion-based defects.
以上詳細に説明したように、本発明によれば、
パウダー巻き込み、デイツケル発生等の操業トラ
ブルなく、介在物系欠陥の少ない高清浄鋼を安定
して連続鋳造することが可能となる。
As explained in detail above, according to the present invention,
It is possible to stably and continuously cast highly clean steel with few inclusion defects without any operational troubles such as powder entrainment or Deitzkel generation.
第１図は本発明を説明するための模式図、第２
図は本発明の適正域を示す説明図、第３図は連鋳
鋳型内の溶鋼流動を示す説明図である。
１……浸漬ノズル、２……鋳型、３……潤滑用
パウダー、４……上昇流、５……巻き込まれたパ
ウダー、６……デイツケル。
Fig. 1 is a schematic diagram for explaining the present invention, Fig. 2 is a schematic diagram for explaining the present invention;
The figure is an explanatory diagram showing the appropriate range of the present invention, and FIG. 3 is an explanatory diagram showing the flow of molten steel in a continuous casting mold. 1... Immersion nozzle, 2... Mold, 3... Lubricating powder, 4... Updraft, 5... Enrolled powder, 6... Deitskell.
Claims (1)
角θ（deg）、ノズル径ｄ（mm）の２孔浸漬ノズル
を浸漬し、該ノズルより溶鋼を吐出して連続鋳造
するに際し、短片メニスカス部位の溶鋼上昇流速
ｕ（ｍ／ｓ）を 0.033≦ｕ≦0.037（１＋1000／Ａ（mm）） とすることを特徴とする連続鋳造方法。 但し、流速ｕは次式により求める計算値であ
る。 Lo＋ｘ／ｄ≦36.5の場合 …ｕ＝6.3dVCAL／Lo＋ｘ（１−sinθ／２） Lo＋ｘ／ｄ＞36.5の場合 …ｕ＝230d2VCAL／（Lo＋ｘ）2（１−sinθ／２） VCAL＝2ABVc／（60πd2） Lo＝Ａ／2cosθ，ｘ＝Atanθ／２＋x0 ｄ：ノズル吐出口径（mm） θ：ノズル吐出角（deg） Ａ：スラブ幅（mm） Ｂ：スラブ厚（mm） Vc：鋳造速度（ｍ／min） VCAL：平均吐出流速（ｍ／sec） x0：浸漬深さ（mm）[Scope of Claims] 1. A two-hole immersion nozzle with a nozzle discharge angle θ (deg) and a nozzle diameter d (mm) is immersed from above almost in the center of the molten steel in the mold, and the molten steel is discharged from the nozzle to perform continuous casting. A continuous casting method characterized in that the rising flow velocity u (m/s) of molten steel at the short piece meniscus portion satisfies 0.033≦u≦0.037 (1+1000/A (mm)). However, the flow velocity u is a calculated value obtained from the following equation. When Lo+x/d≦36.5...u=6.3dV CAL /Lo+x(1-sinθ/2) When Lo+x/d>36.5...u=230d 2 V CAL /(Lo+x) 2 (1-sinθ/2) V CAL =2ABVc/(60πd 2 ) Lo=A/2cosθ, x=Atanθ/2+x 0 d: Nozzle discharge opening diameter (mm) θ: Nozzle discharge angle (deg) A: Slab width (mm) B: Slab thickness (mm) Vc : Casting speed (m/min) V CAL : Average discharge flow rate (m/sec) x 0 : Immersion depth (mm)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27629285A JPS62137153A (en) | 1985-12-09 | 1985-12-09 | Continuous casting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27629285A JPS62137153A (en) | 1985-12-09 | 1985-12-09 | Continuous casting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62137153A JPS62137153A (en) | 1987-06-20 |
| JPS6358665B2 true JPS6358665B2 (en) | 1988-11-16 |
Family
ID=17567417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27629285A Granted JPS62137153A (en) | 1985-12-09 | 1985-12-09 | Continuous casting method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62137153A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2868174B2 (en) * | 1993-03-09 | 1999-03-10 | 川崎製鉄株式会社 | Continuous casting method for stainless steel |
-
1985
- 1985-12-09 JP JP27629285A patent/JPS62137153A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62137153A (en) | 1987-06-20 |
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