JP2567452B2 - Continuous casting method for steel - Google Patents
Continuous casting method for steelInfo
- Publication number
- JP2567452B2 JP2567452B2 JP10046288A JP10046288A JP2567452B2 JP 2567452 B2 JP2567452 B2 JP 2567452B2 JP 10046288 A JP10046288 A JP 10046288A JP 10046288 A JP10046288 A JP 10046288A JP 2567452 B2 JP2567452 B2 JP 2567452B2
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- tundish
- steel
- inert gas
- 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.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/112—Treating the molten metal by accelerated cooling
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） 本発明は鋼の中心偏析の低減を目的とした鋼の連続鋳
造方法に関するものである。TECHNICAL FIELD The present invention relates to a continuous casting method for steel for the purpose of reducing center segregation of steel.
（従来の技術） 従来、連続鋳造により製造される鋼片の中心偏析を低
減させる方法として、次のような技術が挙げられる。(Prior Art) Conventionally, as a method of reducing the center segregation of a steel slab produced by continuous casting, the following technology can be mentioned.
等軸晶率を増加させることにより中心偏析を低減す
る方法。A method of reducing center segregation by increasing the equiaxed crystal ratio.
凝固途中あるいは末期における残溶鋼の鋳片内での
流動を抑制、制御する方法。A method for suppressing and controlling the flow of residual molten steel in a slab during or after solidification.
このうち、の等軸晶率を増加させることにより中心
偏析を低減させる手段としては、 （イ） 溶鋼の鋳造温度を出来るだけ凝固温度に近づけ
て鋳造する。Among these, as means for reducing the center segregation by increasing the equiaxed crystal ratio of (a), casting is performed with the molten steel casting temperature as close to the solidification temperature as possible.
（ロ） モールド、二次冷却帯で電磁攪拌を行なって柱
状晶の発達の抑制と、結晶核の増殖を行ない、等軸晶率
を増加させる。(B) Electromagnetic stirring is performed in the mold and the secondary cooling zone to suppress the growth of columnar crystals and to grow crystal nuclei to increase the equiaxed crystal ratio.
（ハ） タンディッシュあるいはモールド内へ鉄片、粉
体等冷材を投入して溶鋼温度を低下させる。(C) Cooling materials such as iron pieces and powder are put into the tundish or mold to lower the molten steel temperature.
等の方法がある。There is a method such as.
又上記の凝固途中あるいは末期における残溶鋼の鋳
片内での流動を抑制、制御する手段としては、 （イ） 二次冷却帯以降のロールアライメントの整備に
よるバルジングの防止。Further, as means for suppressing and controlling the flow of the residual molten steel in the slab during the solidification or in the final stage, (a) prevention of bulging by maintenance of roll alignment after the secondary cooling zone.
（ロ） 凝固末期における鋳片の軽圧下による溶鋼流動
制御 により、中心偏析の低減策がとられている。(B) Measures to reduce center segregation are taken by controlling the molten steel flow by lightly reducing the slab in the final stage of solidification.
実際の連続鋳造方法においては、上述の手段のそれぞ
れが単独で用いられているのではなく、中心偏析低減の
ための各種の手段を組み合せて実施されている。In the actual continuous casting method, each of the above-mentioned means is not used alone, but is implemented by combining various means for reducing the center segregation.
例えば、低温鋳造を達成させるための厳密な温度管理
や加熱機能を持ったタンディッシュによる温度保障、あ
るいは鋼片、鋼粉等の冷材の投入等が実施されており、
引続いてモールド及び二次冷却帯における電磁攪拌の実
施、さらには凝固末期でのガイドロール群による軽圧下
による溶鋼流動の制御等が実施されている。For example, strict temperature control to achieve low-temperature casting and temperature guarantee by a tundish with a heating function, or the introduction of cold materials such as steel slabs, steel powder, etc. are carried out.
Subsequently, electromagnetic stirring is carried out in the mold and the secondary cooling zone, and further, molten steel flow control by light reduction by the guide roll group at the final stage of solidification is carried out.
（解決しようとする課題） 上述したように、鋳造温度をできるだけ凝固点に近づ
けるのが等軸晶率の増加、中心偏析低減に有効な手段の
一つである。そのため、鋳造温度を低くする努力が続け
られてきた。しかし、溶鋼温度が下り過ぎた場合のタン
ディッシュノズルの閉塞事故や鋳造時期による凝固組織
の変動等の問題点がある。(Problems to be Solved) As described above, making the casting temperature as close to the freezing point as possible is one of the effective means for increasing the equiaxed crystal ratio and reducing the center segregation. Therefore, efforts have been made to lower the casting temperature. However, there are problems such as a clogged accident of the tundish nozzle when the molten steel temperature is too low, and a change in solidification structure due to casting time.
又冷却材の投入も等軸晶化には有効な手段であるが、
冷却材の溶け残りや、モールドスラグの巻き込み等の問
題がある。In addition, the addition of coolant is also an effective means for equiaxed crystallization,
There are problems such as unmelted coolant and entrapment of mold slag.
（課題を解決するための手段） 本発明は上述の問題点を解消し、連鋳々片の等軸晶率
を増加して中心偏析を改善する新規な鋼の連続鋳造方法
を提供するもので、その特徴は、タンディッシュ内で鋳
造中の溶鋼の一部を不活性ガス噴流により噴霧、液滴化
し、それが飛散、飛行中にその一部又は全部を凝固させ
た後、タンディッシュ内溶鋼へ落下させて溶鋼中に凝固
粒子を懸濁させ、これをモールドへ注入することにあ
る。(Means for Solving the Problems) The present invention solves the above-mentioned problems and provides a novel continuous casting method for steel that increases the equiaxed crystal ratio of continuous cast pieces and improves center segregation. , Its characteristic is that a part of the molten steel being cast in the tundish is sprayed by an inert gas jet, atomized, drops, and then scattered, solidifying part or all of it during flight, and then the molten steel in the tundish. The purpose is to drop the solidified particles in molten steel by pouring them into a mold.
第１図は本発明の連続鋳造方法の具体例の説明図であ
る。FIG. 1 is an explanatory view of a specific example of the continuous casting method of the present invention.
同図において、（１）はレードル、（２）はタンディ
ッシュ、（３）はモールドを示し、溶鋼を上記レードル
（１）→タンディッシュ（２）→モールド（３）へと移
送して連続鋳造を行なう。In the figure, (1) is a ladle, (2) is a tundish, and (3) is a mold. Molten steel is transferred from the ladle (1) to the tundish (2) to the mold (3) for continuous casting. Do.
図面に示すように、タンディッシュ（２）内溶鋼
（７）の湯面上に、不活性ガス雰囲気用カバー（４）を
設置し、Ｎ2、Ar等の不活性ガスを不活性ガス導入パイ
プ（５）から溶鋼（７）内に導き、湯面下に設けた不活
性ガス噴流ノズル（10）から噴出させる。この不活性ガ
ス噴流によりタンディッシュ（２）内の溶鋼（７）の一
部を不活性ガス雰囲気用カバー（４）内において噴霧、
液滴化し、それが上記カバー（４）内で飛散、飛行中に
凝固させて凝固粒子（９）を生成させる。この凝固粒子
（９）は自由落下により溶鋼（７）に再び戻り、溶鋼
（７）中に懸濁させ、これをタンディッシュ（２）の株
に設けたノズル（12）よりモールド（３）内へ導入す
る。As shown in the drawing, a cover (4) for an inert gas atmosphere is installed on the molten steel (7) in the tundish (2), and an inert gas such as N 2 or Ar is introduced into the pipe. It is introduced into the molten steel (7) from (5) and ejected from an inert gas jet nozzle (10) provided below the molten metal surface. By this inert gas jet, a part of the molten steel (7) in the tundish (2) is sprayed in the inert gas atmosphere cover (4),
It drops into droplets, which scatter in the cover (4) and solidify during flight to produce solidified particles (9). The solidified particles (9) return to the molten steel (7) again by free fall and are suspended in the molten steel (7), and the suspended particles are suspended in the mold of the tundish (2) from the nozzle (12) in the mold (3). Introduce to.
この際、不活性ガス雰囲気用カバー（４）の外側の溶
鋼湯面はスラグ（８）で覆って保温及び酸化抑制を行な
い、上記カバー（４）内はスラグの巻き込み等の問題が
あり、裸の湯面にしておく。At this time, the molten steel surface outside the inert gas atmosphere cover (4) is covered with a slag (8) to keep the heat and prevent oxidation, and there is a problem such as slag entrapment in the cover (4). Leave it on the water surface.
なお、図面において、（６）は排気ダクト、（11）は
流量制御用ストッパーヘッドである。In the drawings, (6) is an exhaust duct and (11) is a flow control stopper head.
（作用） 上述した本発明の連続鋳造方法によれば、不活性ガス
の噴流により生じた溶鋼の噴霧流が不活性ガス雰囲気用
カバー内の不活性ガス雰囲気中を飛散、飛行し、主とし
て放射により冷却され凝固する。この凝固した粒子は自
由落下により再びタンディッシュ内溶鋼に戻る。(Operation) According to the above-described continuous casting method of the present invention, the spray flow of molten steel generated by the jet flow of the inert gas scatters and flies in the inert gas atmosphere in the cover for the inert gas atmosphere, and mainly by radiation. Cools and solidifies. The solidified particles return to the molten steel in the tundish again by free fall.
溶鋼の噴霧、液滴化は不活性ガス噴流の吹出し位置、
圧力及び流量により直径の分布状態や飛散距離が異なっ
てくる。又飛散中に凝固の完了するもの、部分凝固した
粒子あるいは液滴のまま再びタンディッシュ内溶鋼に還
流する。Spraying of molten steel and formation of droplets are performed at the position where the inert gas jet is blown,
The distribution state of diameters and the scattering distance vary depending on the pressure and flow rate. In addition, the solidification is completed during the scattering, and the partially solidified particles or droplets are returned to the molten steel in the tundish again.
上述のように、タンディッシュ内に落下した凝固粒子
は溶鋼中に浮遊、懸濁してモールドへと導入される。As described above, the solidified particles dropped in the tundish are suspended and suspended in the molten steel and introduced into the mold.
この凝固粒子は鋳片の等軸晶の結晶核となり、連鋳々
片の凝固組織を著しく改善して等軸晶率を増加させ、中
心偏析を低減させる。勿論、凝固粒子の一部分は溶鋼中
で再溶解されるため、飛散中に凝固した粒子の全量が有
効な結晶核とはならない。しかし、副次的効果として、
これら凝固粒子が再溶解時に溶解潜熱を奪うため、周辺
の溶鋼の冷却効果がある。同様に未凝固のままで溶鋼へ
落下した液滴も若干の冷却効果をもつ。The solidified particles become equiaxed crystal nuclei of the slab, significantly improve the solidification structure of the continuously cast slab, increase the equiaxed crystal ratio, and reduce center segregation. Of course, a part of the solidified particles is redissolved in the molten steel, so that the total amount of the particles solidified during the scattering does not become effective crystal nuclei. However, as a side effect,
Since these solidified particles take away the latent heat of melting during remelting, they have the effect of cooling the molten steel around them. Similarly, the droplets that have fallen into the molten steel without being solidified also have a slight cooling effect.
（実施例） 次に本発明の実施例について説明する。(Example) Next, the Example of this invention is described.
0.82％Ｃ、0.23％Si、0.51％Mnの高炭素鋼30tを溶精
し、第１図に示すように順次鋳造を実施した。High-carbon steel 30t of 0.82% C, 0.23% Si, and 0.51% Mn was smelted and sequentially cast as shown in FIG.
タンディッシュ内の溶鋼温度は高周波加熱により1485
〜1495℃の範囲内に調整した。タンディッシュ内に設置
した不活性ガス雰囲気用カバーは、内寸法が幅500mm、
奥行1000mm、高さ800mmとした。不活性ガスの噴流吹出
については圧力2.5atm、流量と吹出し口の深さを調整し
て上記カバー内で対面の壁に飛散粒子が到達しないよう
設定した。飛散、噴霧された溶鋼の重量は大略80g/sec
であった。モールド内寸法は160×250mmの矩形断面に鋳
造、1.5m/minで引抜いた。又二次冷却帯で電磁攪拌処理
を行ない、連続鋳々片サンプルを採取した。The molten steel temperature in the tundish is 1485 due to high frequency heating.
The temperature was adjusted within the range of ~ 1495 ° C. The inert gas atmosphere cover installed in the tundish has an internal dimension of 500 mm,
The depth is 1000 mm and the height is 800 mm. The pressure of the jet of inert gas was 2.5 atm, and the flow rate and the depth of the outlet were adjusted so that the scattered particles did not reach the facing wall in the cover. The weight of the molten steel that has been scattered and sprayed is approximately 80 g / sec.
Met. The inner dimension of the mold was cast in a rectangular cross section of 160 × 250 mm and drawn at 1.5 m / min. In addition, electromagnetic stir processing was performed in the secondary cooling zone to sample continuous cast pieces.
ブルームは横断面のマクロ腐食及び中心の炭素の偏析
状況を調査した。Bloom investigated macro-corrosion in cross section and segregation of central carbon.
実験は鋳造時期の影響や、鋳造温度の影響を考慮し
て、それぞれ10ヒートづつ実施して評価した。The experiment was evaluated by conducting 10 heats each, considering the influence of casting time and the influence of casting temperature.
結果は第１表に示す通りで、本発明方法によれば、等
軸晶率が著しく改善されており、炭素の偏析率も低減さ
れていることが確認された。The results are shown in Table 1, and it was confirmed that the method of the present invention significantly improved the equiaxed crystal ratio and reduced the carbon segregation ratio.
（発明の効果） 以上説明したように、本発明の連続鋳造方法によれ
ば、連鋳々片の等軸晶率が著しく改善され、鋳片中心部
のＣ、Ｐ、Ｓ等の濃化偏析が抑制される。 (Effect of the invention) As described above, according to the continuous casting method of the present invention, the equiaxed crystal ratio of continuously cast pieces is remarkably improved, and the concentrated segregation of C, P, S, etc. at the center of the cast piece. Is suppressed.
従って、この鋳片を用いた圧延製品、二次加工品は均
質で、加工性のすぐれたものが得られる。Therefore, the rolled product and the secondary processed product using this slab are homogeneous and have excellent workability.
第１図は本発明の鋼の連続鋳造方法の具体例の説明図で
ある。 第２図は等軸晶率の説明図である。 １……レードル、２……タンディッシュ、３……モール
ド、４……不活性ガス雰囲気用カバー、５……不活性ガ
ス導入パイプ、６……排気ダクト、７……溶鋼、８……
スラグ、９……凝固粒子、10……不活性ガス噴流ノズ
ル、11……流量制御用ストッパーヘッド、12……タンデ
ィッシュノズル。FIG. 1 is an illustration of a specific example of the continuous casting method for steel according to the present invention. FIG. 2 is an illustration of the equiaxed crystal ratio. 1 ... Ladle, 2 ... Tundish, 3 ... Mold, 4 ... Cover for inert gas atmosphere, 5 ... Inert gas introduction pipe, 6 ... Exhaust duct, 7 ... Molten steel, 8 ...
Slag, 9 ... Solidified particles, 10 ... Inert gas jet nozzle, 11 ... Flow control stopper head, 12 ... Tundish nozzle.
Claims (1)
ドへと移送して鋳造する鋼の連続鋳造方法において、タ
ンディッシュ内で鋳造中の溶鋼の一部を不活性ガス噴流
により噴霧、液滴化し、それが飛散、飛行中にその一部
又は全部を凝固させた後、タンディッシュ内溶鋼へ落下
させて溶鋼中に凝固粒子を懸濁させ、これをモールドへ
注入することを特徴とする鋼の連続鋳造方法。1. In a continuous casting method for steel in which molten steel is transferred to a ladle-tundish-mold and cast, a part of the molten steel being cast in the tundish is atomized and jetted by an inert gas jet, It is scattered, and after solidifying a part or all of it during flight, it is dropped into the molten steel in the tundish to suspend the solidified particles in the molten steel, which is then poured into a mold. Casting method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10046288A JP2567452B2 (en) | 1988-04-22 | 1988-04-22 | Continuous casting method for steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10046288A JP2567452B2 (en) | 1988-04-22 | 1988-04-22 | Continuous casting method for steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01271043A JPH01271043A (en) | 1989-10-30 |
| JP2567452B2 true JP2567452B2 (en) | 1996-12-25 |
Family
ID=14274575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10046288A Expired - Fee Related JP2567452B2 (en) | 1988-04-22 | 1988-04-22 | Continuous casting method for steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2567452B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102764868A (en) * | 2012-07-11 | 2012-11-07 | 北京科技大学 | Blowing and refining device and method used for removing tundish molten steel inclusion |
-
1988
- 1988-04-22 JP JP10046288A patent/JP2567452B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102764868A (en) * | 2012-07-11 | 2012-11-07 | 北京科技大学 | Blowing and refining device and method used for removing tundish molten steel inclusion |
| CN102764868B (en) * | 2012-07-11 | 2015-01-07 | 北京科技大学 | Blowing and refining device and method used for removing tundish molten steel inclusion |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01271043A (en) | 1989-10-30 |
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|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |