JPH05136B2 - - Google Patents
Info
- Publication number
- JPH05136B2 JPH05136B2 JP60227593A JP22759385A JPH05136B2 JP H05136 B2 JPH05136 B2 JP H05136B2 JP 60227593 A JP60227593 A JP 60227593A JP 22759385 A JP22759385 A JP 22759385A JP H05136 B2 JPH05136 B2 JP H05136B2
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- mold
- immersion
- nozzle
- discharge hole
- 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 - Lifetime
Links
- 238000007654 immersion Methods 0.000 claims description 37
- 229910000831 Steel Inorganic materials 0.000 claims description 32
- 239000010959 steel Substances 0.000 claims description 32
- 238000005266 casting Methods 0.000 claims description 11
- 238000009749 continuous casting Methods 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 6
- 230000003749 cleanliness Effects 0.000 claims description 4
- 230000007547 defect Effects 0.000 description 9
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 8
- 239000000843 powder Substances 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000002344 surface layer Substances 0.000 description 5
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000655 Killed steel Inorganic materials 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、連続鋳造におけるモールド内溶鋼の
鋳込み条件を限定することによつて鋳込まれた鋳
片の表面清浄を改善する連続鋳造方法に関するも
のである。[Detailed Description of the Invention] Industrial Application Field The present invention relates to a continuous casting method that improves the surface cleanliness of a cast slab by limiting the casting conditions for molten steel in a mold during continuous casting. be.
従来技術
連続鋳造用浸漬ノズルは鋳込が開始されてから
終了する迄の間は、従来よりその浸漬深さは変え
られることがなく一定の深さが保たれた状態で行
なわれていた。Prior Art Conventionally, the immersion depth of a continuous casting immersion nozzle is maintained at a constant level from the start to the end of casting without being changed.
発明が解決しようとする問題点
従つて、浸漬ノズルの浸漬深さが一定鋳込の場
合、鋳込初期、末期および定常鋳込みにおいても
何らかの原因で鋳込速度が低下した場合、浸漬ノ
ズルの吐出孔よりの溶鋼吐出流速が低下し、モー
ルド内で溶鋼が十分に均一混合されず結果として
鋳込まれた鋳片の表面にAl2O3介在物が集積し、
それを取除くために鋳込まれた鋳片をスカーフイ
ング手入れをしなければならないという問題があ
つた。Problems to be Solved by the Invention Therefore, in the case of casting where the immersion depth of the immersion nozzle is constant, if the casting speed decreases for some reason during the initial, final and steady pouring, the discharge hole of the immersion nozzle The flow rate of molten steel decreases, and the molten steel is not mixed uniformly within the mold, resulting in Al 2 O 3 inclusions accumulating on the surface of the cast slab.
There was a problem in that the cast pieces had to be scarfed to remove them.
問題点を解決するための手段
本発明は上記問題点を解決するためになされた
ものであつて、鋳込まれた鋳片をスカーフイング
手入れすることなく次の圧延工程に流しても製品
である冷延コイルのスリーバー疵の発生率が0.10
％以下に収まる連続鋳造方法を提供するものであ
る。即ち、連続鋳造の鋳込方法において、下記(1)
(2)式にもとづき鋳型内溶鋼体積Ｖに相等する溶鋼
の均一混合時間τが2secから5secの範囲に入るべ
く浸漬ノズルの浸漬深さｈを制御することによつ
て鋳込まれた鋳片の表面清浄を改善することを特
徴とする連続鋳造方法である。Means for Solving the Problems The present invention has been made to solve the above problems, and it is possible to produce a product even if the cast slab is passed to the next rolling process without scarfing. The incidence of sliver defects in cold-rolled coils is 0.10.
% or less. In other words, in the casting method of continuous casting, the following (1)
Based on equation (2), the immersion depth h of the immersion nozzle is controlled so that the uniform mixing time τ of molten steel equivalent to the molten steel volume V in the mold falls within the range of 2 seconds to 5 seconds. This continuous casting method is characterized by improved surface cleanliness.
τ＝V1/3／ｖ …(1)
ｈ＝Ｖ／Ｌ・ｄ＋１／２Ｌ・tanθ …(2)
式中 τ：モールド内のＶ体積に相等する溶鋼が
均一に混合される迄の時間（sec）
Ｖ：モールド内の溶鋼表面と浸漬ノズル
と、該ノズルより吐出される溶鋼流と
により囲まれる溶鋼の体積（cm3）
ｖ：浸漬ノズルの吐出孔での溶鋼流出速度
（cm／sec）
ｋ：定数
ｈ：浸漬ノズルのモールド内溶鋼表面から
ノズル吐出孔上端までの浸漬深さ
（cm）
Ｌ：浸漬ノズル吐出孔より短辺モールドま
での距離（cm）
θ：浸漬ノズルの吐出孔より溶鋼が吐出す
る角度（゜）
ｄ：短辺モールドの巾（cm）
本発明の重要な構成は、上記(1)式の均一混合時
間τを2secから5secに収めることであり、該結果
は水モデル実験により知見したものである。即ち
τが5sec以上となれば鋳片表層部のAl2O3量が
30ppm以上となり（第２図）、該鋳片を冷延コイ
ルに圧延すれば、スリーバー疵の発生率（％）は
上昇するので好ましくない（第３図）。τ=V 1/3 /v...(1 ) h=V/L・d+1/2L・tanθ...(2) In the formula, τ: Time until molten steel equivalent to V volume in the mold is mixed uniformly ( sec) V: Volume of molten steel surrounded by the molten steel surface in the mold, the immersion nozzle, and the molten steel flow discharged from the nozzle (cm 3 ) v: Molten steel flow rate at the discharge hole of the immersion nozzle (cm/sec) k: Constant h: Immersion depth from the molten steel surface in the mold of the immersion nozzle to the top of the nozzle discharge hole (cm) L: Distance from the immersion nozzle discharge hole to the short side mold (cm) θ: Molten steel from the immersion nozzle discharge hole Discharge angle (°) d: Width of the short side mold (cm) An important feature of the present invention is to keep the uniform mixing time τ in equation (1) above from 2 seconds to 5 seconds, and the result is a water model. This was discovered through experiments. In other words, if τ is 5 sec or more, the amount of Al 2 O 3 in the surface layer of the slab will be
30 ppm or more (Fig. 2), and if the slab is rolled into a cold-rolled coil, the occurrence rate (%) of sliver defects will increase, which is not preferable (Fig. 3).
又、τが2sec未満になればモールド内溶鋼の撹
拌が強くなりすぎて、モールド内パウダーの巻き
込み現象が生じて、冷延コイル表面にパウダー起
因の疵の発生率（％）が上昇するので好ましくな
い（第４図）。 In addition, if τ is less than 2 sec, the stirring of the molten steel in the mold becomes too strong, and the phenomenon of entrainment of powder in the mold occurs, which increases the incidence (%) of powder-induced defects on the surface of the cold-rolled coil, which is preferable. No (Figure 4).
本発明の好ましいτの範囲は2secから4secであ
る。 The preferred range of τ in the present invention is 2 seconds to 4 seconds.
均一混合時間τを上記範囲に収めるためには、
浸漬ノズルの浸漬深さｈを(2)式に従つてコントロ
ールすればよい。具体的にはタンデイツシユ架台
に上下機能を設けて該浸漬深さを制御するのが好
ましいが、他の方法であつてもよい。 In order to keep the uniform mixing time τ within the above range,
The immersion depth h of the immersion nozzle may be controlled according to equation (2). Specifically, it is preferable to provide the tundish pedestal with a vertical function to control the immersion depth, but other methods may also be used.
作 用
上下機能を有するタンデイツシユと、該タンデ
イツシユ、固設されたスライデイングノズル（い
ずれも図示せず）と該スライデイングノズルに連
結された浸漬ノズル１とモールド２とよりなる連
続鋳造設備において、浸漬ノズル１の吐出孔角度
θ４、溶鋼表面５から浸漬ノズル吐出孔上端まで
の距離ｈ６、吐出孔３からの溶鋼流出速度ｖ７、
浸漬ノズル吐出孔より短辺モールド２までの距離
Ｌ８にセツトした状態で浸漬ノズル１より溶鋼を
注入する。注入された溶鋼は吐出孔を介して流出
速度ｖをもつてモールド内へ注入される。又、モ
ールド内の溶鋼表面５と浸漬ノズル１と、該ノズ
ルより吐出される溶鋼流とにより囲まれる溶鋼の
体積９（第１図斜線部）と、該体積に相等する溶
鋼が均一に混合される迄の時間をτ、浸漬ノズル
の浸漬深さをｈとし前記(1)(2)式に従つて第１図に
示す連続鋳造設備を用いて鋳造し、表面清浄の優
れた鋳片を得るものである。Function: In continuous casting equipment consisting of a tundish with a vertical function, the tundish, a fixed sliding nozzle (none of which is shown), and an immersion nozzle 1 and a mold 2 connected to the sliding nozzle, the immersion The discharge hole angle θ4 of the nozzle 1, the distance h6 from the molten steel surface 5 to the upper end of the immersion nozzle discharge hole, the flow rate of molten steel from the discharge hole 3 v7,
Molten steel is injected from the immersion nozzle 1 with the distance L8 from the immersion nozzle discharge hole to the short side mold 2 set. The injected molten steel is injected into the mold through the discharge hole at an outflow velocity v. Further, the volume 9 (shaded area in Figure 1) of molten steel surrounded by the molten steel surface 5 in the mold, the immersion nozzle 1, and the molten steel flow discharged from the nozzle, and the molten steel equivalent to this volume are uniformly mixed. Casting is performed using the continuous casting equipment shown in Fig. 1 according to equations (1) and (2) above, with the time taken until τ and the immersion depth of the immersion nozzle set as h, to obtain slabs with excellent surface cleanliness. It is something.
実施例
鋼種：冷延用低炭素Alキルド鋼（％）
Ｃ：0.05 Si：0.01 Mn：0.25 Ｐ：0.015
Ｓ：0.012 Al：0.033
鋳片サイズ：巾：1250mm
短辺モールド巾ｄ：230mm
鋳込速度：1.8ｍ／min
溶鋼体積Ｖ：19850cm3
流出速度：ｖ：88cm／sec
定数：Ｋ：13
浸漬深さｈ：20cm
距離Ｌ：55cm
吐出角度θ：２孔上向10゜
τを2secから6secで鋳込んだ鋳片表層部Al2O3
量を示した結果が第２図である。更に該鋳片を冷
延コイルとした時のスリーバー疵発生率を第３図
に示した。さらにまた、該鋳片を冷延コイルとし
た時のτと冷延コイルパウダー疵発生率を第４図
に示した。Example steel type: Low carbon Al killed steel for cold rolling (%) C: 0.05 Si: 0.01 Mn: 0.25 P: 0.015
S: 0.012 Al: 0.033 Slab size: Width: 1250 mm Short side mold width d: 230 mm Casting speed: 1.8 m/min Molten steel volume V: 19850 cm 3 Outflow speed: V: 88 cm/sec Constant: K: 13 Immersion depth h: 20cm Distance L: 55cm Discharge angle θ: 2 holes upward 10° Cast slab surface layer Al 2 O 3 with τ cast from 2 seconds to 6 seconds
Figure 2 shows the results showing the amount. Furthermore, the occurrence rate of sliver defects when the slab was made into a cold-rolled coil is shown in FIG. Furthermore, FIG. 4 shows τ and the incidence of cold-rolled coil powder defects when the slab was made into a cold-rolled coil.
尚、第２図のτを2secから4secにコントロール
鋳込みした時の鋳込時間と浸漬ノズル深さの関係
を示したものが第５図であり、τを4sec以下にコ
ントロールすればAl2O3量は30ppm以下に収まる
ことを示している。また、図４に示すとおり、τ
を2sec以下にコントロールすれば、冷延コイルパ
ウダー疵発生率を0.01％以下に抑制できる。 In addition, Figure 5 shows the relationship between the casting time and the immersion nozzle depth when τ in Figure 2 is controlled from 2 seconds to 4 seconds, and if τ is controlled to 4 seconds or less, Al 2 O 3 This shows that the amount is below 30ppm. Also, as shown in Figure 4, τ
By controlling the time to 2 seconds or less, the occurrence rate of cold-rolled coil powder defects can be suppressed to 0.01% or less.
参考までに従来の鋳込パターンを第６図に示し
た。 For reference, a conventional casting pattern is shown in Figure 6.
発明の効果
以上説明したように、溶鋼の均一混合時間τを
2secから5secの範囲に入るべく浸漬ノズルの浸漬
深さｈを制御することによつて鋳込まれた鋳片表
層部のAl2O3量は30ppm以下にコントロール出
来、鋳片のスカーフイング手入れをすることなく
冷延コイルのスリーバー疵の発生率を大巾に低下
させることが出来る優れた効果を有するものであ
る。Effects of the invention As explained above, the uniform mixing time τ of molten steel is
By controlling the immersion depth h of the immersion nozzle so that it falls within the range of 2 seconds to 5 seconds, the amount of Al 2 O 3 in the surface layer of the cast slab can be controlled to 30 ppm or less, making it possible to maintain the scarfing of the slab. This has the excellent effect of greatly reducing the incidence of sliver defects in cold-rolled coils without causing damage.
第１図は本発明の概略説明図、第２図はτと鋳
片表層部Al2O3量の関係図、第３図は鋳片表層部
Al2O3量と冷延コイルスリーバー疵発生率の関係
図、第４図はτと冷延コイルパウダー疵発生率の
関係図、第５図は時間と浸漬ノズル深さの関係
図、第６図は従来の鋳込パターンを示す図であ
る。
Fig. 1 is a schematic explanatory diagram of the present invention, Fig. 2 is a relationship between τ and the amount of Al 2 O 3 in the surface layer of the slab, and Fig. 3 is a diagram showing the relationship between τ and the amount of Al 2 O 3 in the surface layer of the slab.
Figure 4 is a diagram showing the relationship between Al 2 O 3 content and the occurrence rate of cold-rolled coil powder defects. Figure 4 is a diagram showing the relationship between τ and the occurrence rate of cold-rolled coil powder defects. FIG. 6 is a diagram showing a conventional casting pattern.
Claims (1)
もとづき鋳型内溶鋼体積Ｖに相当する溶鋼の均一
混合時間τが2secから5secの範囲に入るべく浸漬
ノズルの浸漬深さｈを制御することによつて鋳込
まれた鋳片の表面清浄を改善することを特徴とす
る連続鋳造方法。 τ＝ＫV1/3／ｖ …(1) ｈ＝Ｖ／Ｌ・ｄ＋１／２Ｌ・tanθ …(2) 式中 τ：モールド内のＶ体積に相当する溶鋼が
均一に混合される迄の時間（sec） Ｖ：モールド内の溶鋼表面と浸漬ノズル
と、該ノズルより吐出される溶鋼流と
により囲まれる溶鋼の体積（cm3） ｖ：浸漬ノズル吐出孔での溶鋼流出速度
（cm／sec） ｋ：定数 ｈ：浸漬ノズルのモールド内溶鋼表面から
ノズル吐出孔上端までの浸漬深さ
（cm） Ｌ：浸漬ノズル吐出孔より短辺モールドま
での距離（cm） θ：浸漬ノズルの吐出孔より溶鋼が吐出す
る角度（゜） ｄ：短辺モールドの巾（cm）。[Claims] 1. In the casting method of continuous casting, based on the following equations (1) and (2), an immersion nozzle is used so that the uniform mixing time τ of molten steel corresponding to the volume V of molten steel in the mold is in the range of 2 seconds to 5 seconds. A continuous casting method characterized in that the surface cleanliness of a cast slab is improved by controlling the immersion depth h of the cast slab. τ=KV 1/3 /v...(1 ) h=V/L・d+1/2L・tanθ...(2) In the formula, τ: Time until the molten steel equivalent to the volume of V in the mold is mixed uniformly ( sec) V: Volume of molten steel surrounded by the molten steel surface in the mold, the immersion nozzle, and the molten steel flow discharged from the nozzle (cm 3 ) v: Molten steel flow rate at the immersion nozzle discharge hole (cm/sec) k : Constant h: Immersion depth from the surface of the molten steel in the mold of the immersion nozzle to the top of the nozzle discharge hole (cm) L: Distance from the immersion nozzle discharge hole to the short side mold (cm) θ: Immersion depth of the molten steel from the discharge hole of the immersion nozzle to the top of the nozzle discharge hole (cm) Discharge angle (°) d: Width of short side mold (cm).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22759385A JPS6289557A (en) | 1985-10-11 | 1985-10-11 | Continuous casting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22759385A JPS6289557A (en) | 1985-10-11 | 1985-10-11 | Continuous casting method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6289557A JPS6289557A (en) | 1987-04-24 |
| JPH05136B2 true JPH05136B2 (en) | 1993-01-05 |
Family
ID=16863350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22759385A Granted JPS6289557A (en) | 1985-10-11 | 1985-10-11 | Continuous casting method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6289557A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160078081A (en) * | 2014-12-24 | 2016-07-04 | 주식회사 포스코 | Non-orinented electrical steel sheet and method for manufacturing the same |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20010064779A (en) * | 1999-12-18 | 2001-07-11 | 이구택 | Method of controlling a deposition depth in a deposition nozzle |
| KR101239537B1 (en) | 2005-12-22 | 2013-03-06 | 주식회사 포스코 | Method for deceasing a depression of strip surface by optimization a deposition depth in submerged entry nozzle |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59107754A (en) * | 1982-12-10 | 1984-06-22 | Nippon Steel Corp | Continuous casting method of aluminum killed steel |
-
1985
- 1985-10-11 JP JP22759385A patent/JPS6289557A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59107754A (en) * | 1982-12-10 | 1984-06-22 | Nippon Steel Corp | Continuous casting method of aluminum killed steel |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160078081A (en) * | 2014-12-24 | 2016-07-04 | 주식회사 포스코 | Non-orinented electrical steel sheet and method for manufacturing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6289557A (en) | 1987-04-24 |
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Legal Events
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| EXPY | Cancellation because of completion of term |