JPS58176064A - Continuous casting method - Google Patents

Abstract

PURPOSE:To adsorb and separate non-metallic inclusions efficiently by exchanging a tundish gate which has plural through-holes and adsorbs and separates the non-metallic inclusions in the through-holes during continuous casting. CONSTITUTION:Molten steel is charged from a ladle into a molten metal receiving bath 2a of a tundish 2 provided with gates 10, 10 having many through-holes 11, and is fed through the holes 11 of the gates 10 into static baths 2b, 2b. The non-metallic inclusions in the molten steel are adsorbed on the inside wall of the holes during the passage of the steel through the holes 11. The gate 10 is exchanged in the time (t) within the range determined by the equation during casting, whereby the inclusions are adsorbed and separated efficiently in the multiple casting as well without decreasing the adsorption and sepn. efficiency for the inclusions. If the gate 10 is not exchanged, the holes 11 are closed on progressing of the adsorption and sepn. of the inclusions on the inside wall of the holes 11, resulting in the decreased adsorption and sepn. efficiency for the inclusions.

Description

【発明の詳細な説明】 この発明は連続鋳造方法に関するもので、複数の貫通孔
を有しこの貫通孔内で非金属介在物を吸着分離するタン
ディツシュ堰を鋳造中に交換することにより非金属介在
物を麹率よく吸着分離することを目的とする。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous casting method, in which a tundish weir that has a plurality of through holes and adsorbs and separates non-metallic inclusions in the through-holes is replaced during casting to eliminate non-metallic inclusions. The purpose is to adsorb and separate substances with good malt efficiency.

連続鋳造において鋳片内に持ち込着れる非金属介在物は
鋳片のｔＩ！面品實および内質を劣化させる。そのため
龜鍋酊−中に含まれる介在物を鋳臘内に流入させない檀
々の混入防止対策がとられている。Non-metallic inclusions that are brought into the slab during continuous casting are the tI of the slab! Deteriorates face quality and inner quality. Therefore, measures are taken to prevent the inclusions contained in the pot from flowing into the pot.

連続鋳造における鋳造方法の概略を第１図に示す。ｆＩ
Ｉ４０連続鋳造において＆Ｊ浴−取鍋（１）から鉤皺の
上部に配置されたタンティッシュ（２）に溶−が注入さ
れて、ここで一時釣に貯留され、このメンディツシュ（
２）のノズル（３）がら―型」）に鋳込まれる。Figure 1 shows an outline of the casting method in continuous casting. fI
In I40 continuous casting, melt is injected from the &J bath ladle (1) into the tongue tissue (2) placed on the top of the hook, where it is temporarily stored, and this mendish (
2) is cast into the nozzle (3).

非金属介在物を鋳皺内に混入させないためには、このタ
ンディツシュ（２）内Ｖ（おいてこれらの介在物をノズ
ル（３）に至らしめぬようにすることが必蚤でＴｏυ、
そのため１こタンディツシュ（２）内に持ち込まれた介
在′Ｊａを可及的速かにタンディツシュ内で浮上分離さ
ぞるような壜（５）の設置などが行なわれている。図中
（５）は浴−の流れ、（７）は凝固シェルを示すしかし
このような構成のタンティッシュを用いても、まだ非金
属介在物の除去は十分ではなく依然として鋳型内に持ち
込まれる介在物が多い。In order to prevent non-metallic inclusions from getting into the casting wrinkles, it is necessary to prevent these inclusions from reaching the nozzle (3) in the tundish (2).
For this reason, a bottle (5) is installed so that the intervention 'Ja brought into the tundish (2) can be floated and separated within the tundish as quickly as possible. In the figure, (5) shows the flow of the bath, and (7) shows the solidified shell. However, even if a tongue tissue with this configuration is used, the removal of non-metallic inclusions is still not sufficient, and the inclusions are still brought into the mold. There are many things.

そこで本願出１人は上記構造のタンティッシュに改良を
加えて堰全面に多数の貫通孔を設け、この貫通孔を溶湯
が通過する際にその内面に介在物が吸着される効果を利
用した一考案を実公昭５２−２７８４３号にて提案撫で
ある。Therefore, the applicant of the present application improved the above-mentioned tongue tissue structure by providing a large number of through holes on the entire surface of the weir, and developed a method that takes advantage of the effect that inclusions are adsorbed to the inner surface when the molten metal passes through the through holes. The idea was proposed in Utility Model Publication No. 52-27843.

この構成を第２図に示す。図中０４叫が′４数の貫通孔
（１１）を肩する堰であり、この堰切ＣＬＬＩによ抄前
記タンディツシュ（２）は受湯浴（ム）と針止浴（２ｂ
）　（２ｂ）とに分離されている。溶鋼は−（１）から
受湯浴（２ｍ）に注入され、堰叫の真通孔ＣＩυを通過
し静止浴（２ｂ）　（２ｂ）に移る　この貫通孔Ｈを通
過すｂ際に介在物は貫通孔Ｏνの内−に吸着される。This configuration is shown in FIG. In the figure, 04 is a weir that shoulders 4 through holes (11), and this weir CLLI allows the above-mentioned tundish (2) to be connected to the receiving bath (mu) and the needle stopping bath (2b).
) (2b). Molten steel is injected into the receiving bath (2 m) from (1), passes through the straight through hole CIυ of the weir, and moves to the static bath (2b) (2b). It is adsorbed into the through hole Oν.

・　　） この提案済の考案によれは介在物の除去舵力は史に向上
し、所定の効果は得らｈるが、介在物の貫通孔内壁への
吸増分庫が進むにつれて貫通孔が閉塞されるため、予め
孔の径は大キくシておかねばならず、そのため貫通孔内
１１０表向積が相対的に減少して介在物の吸着分離効率
が低下するという問題がある。また閉１が起こつ喪場合
には、それ以上の介在−の１着分間はなされず、多連鋳
時の介在物の低減対策とはな９得ないなどの問題がある
。・ ) According to this proposed device, the steering force for removing inclusions is improved to a greater extent and the desired effect is achieved, but as the inclusions are absorbed into the inner wall of the through-hole, the through-hole becomes clogged. Therefore, the diameter of the hole must be made large in advance, which causes a problem in that the surface area of the through hole 110 is relatively reduced and the efficiency of adsorption and separation of inclusions is reduced. In addition, in the case of occlusion 1, no further interposition is performed for 1 time, and there is a problem that it cannot be used as a measure to reduce inclusions during multiple casting.

本発明は以上の問題を解決するためになされたものであ
り、前記複数の貫通孔を有するｊＩＩＩｔ−１鋳造中に
次式 ％式％ （３） （） ） （） て定める範囲内０時間ｔで交換し、介在物の吸着分離効
率を低下させることなく多連鋳時にも効率よく介在物を
１着分間しようとするものである。The present invention has been made to solve the above problems, and during the casting of jIIIt-1 having the plurality of through holes, 0 time t within the range defined by the following formula % formula % (3) () ) () This is intended to efficiently remove inclusions per coat even during multiple casting without reducing the efficiency of adsorption and separation of inclusions.

本発明省らは、まず堰の貫通孔内壁に吸着される介在物
の吸着速度について調査を加え九結果、時間の経過につ
れて貫通孔の極が小さくなり、一定の限度を超えると溶
鋼の通過速度がかえって速ＯＤ１通過した介在物の浮上
分離が悪くなり逆効果となる仁とがわかった。この限度
時間が上記した ＆Ｉ　Ｘ　１０−”ＸＡＸＶｃ　＞ｔ であり、この時間前に堰を変換することにより介在物の
効果的な除去を継続することが１工能となる。The Ministry of Invention and others first investigated the adsorption speed of inclusions adsorbed on the inner wall of the weir's through-hole, and found that as time passes, the through-hole's pole becomes smaller, and when it exceeds a certain limit, the passage speed of molten steel increases. However, it was found that the flotation and separation of inclusions that passed through OD1 at a high speed worsened, resulting in the opposite effect. This time limit is the above-mentioned &I X 10-''XAXVc >t, and it takes one skill to continue effective removal of inclusions by converting the weir before this time.

この壜の交換サイクルは介在物の除去という観点からは
短い方が好ましいが、経済性の点から、 ｔ〉□・・・・・・・・・・・・・・・・・・・・・・
・・・・・・・（２）１．３ＸＩＱ−’ＸＡＸＶｃ とすゐのが好ましい。A shorter exchange cycle for this bottle is preferable from the perspective of removing inclusions, but from an economic point of view, t〉□・・・・・・・・・・・・・・・・・・・・・・
(2) 1.3XIQ-'XAXVc is preferable.

なお貫通孔の直径Ｔは舒鋼の通過性と介在物の付着性の
点から上限と下限が決定される。Note that the upper and lower limits of the diameter T of the through hole are determined from the viewpoints of the passability of the steel and the adhesion of inclusions.

すなわち貫通孔径があまり小さいと溶−が最初に通過す
るときに貫通孔内で溶銅が凝固して貫通孔が閉塞してし
まう。この現象が起こる最小径は、約ｒ−０，４ｍであ
る。一方、ｒ〉４国であゐと付着効率が悪く本発明の効
果は小さい。したがって貫通孔の直径ｒは次式に示され
る範囲内に定められるのが好ましい。That is, if the diameter of the through-hole is too small, the molten copper will solidify within the through-hole when the molten metal passes through it for the first time, causing the through-hole to become clogged. The minimum diameter at which this phenomenon occurs is approximately r-0.4 m. On the other hand, in countries r〉4, the adhesion efficiency is poor and the effect of the present invention is small. Therefore, it is preferable that the diameter r of the through hole is determined within the range shown by the following equation.

０．４ｅＩ１１＜ｒ＜４ｃ１１１ なお、貫通孔は円形のほが正方形など他の形状でも良い
ことは首うまでもない１、この場合には前記の直’ｆｌ
ｋ　ｒ　＃′ｉ面積が勢しい円の直径で定義する４０と
する。0.4eI11<r<4c111 It goes without saying that the through-hole may have other shapes such as circular or square1.In this case, the above-mentioned straight
Let k r #'i be 40, which is defined by the diameter of a vigorous circle.

次に実ｌｌｌＡ４５を示す。Next, IllA45 is shown.

実施例 ＩＱ、５ｍＢ　　の湾―蓋２ストランドスラブ連鋳機に
より、！５０Ｘ２０００■のスラブを鋳造速度１．８　
ｍ／ｗｉｍで鋳造した。Example IQ, 5 mB bay-lid 2 strand slab continuous caster! Casting speed of 50×2000■ slab 1.8
Cast with m/wim.

堆鍋容量は１８０　ｔ＠ｎ　で、タンティッシュとして
９２図に示す構造のものを用い貫通孔αルの径を２３と
した。また対象銅は下掲表に示す低炭素アルミキルド鋼
とした。The capacity of the composter was 180 t@n, and the tongue tissue having the structure shown in Fig. 92 was used, and the diameter of the through hole α was 23 mm. The target copper was low carbon aluminum killed steel shown in the table below.

上記条件を０式に代入すると、 一〇　ｍｉｎ　＞　ｔ　　となって 堰の交換サイクルを６０分以内とする必要があることが
わかる。そこで本発明方法として堰を４０分毎に交換し
、基音交換しガい従来法と比較した。その結果を第３図
に示す。Substituting the above conditions into Equation 0, it becomes clear that 10 min > t, and it is necessary to keep the weir replacement cycle within 60 minutes. Therefore, as the method of the present invention, the weir was replaced every 40 minutes and compared with the conventional method in which the fundamental tone was replaced. The results are shown in FIG.

第１図よシ堰を交換し表い従来法で＃ｉ鋳造時間が長く
表るにつれて鋳片内介在物量は電機に増加し、鋳造時間
が６０分を越えると貫通孔の閉寒が進行して吸着分離効
果がなくなることがわかる。一方、本発明を用いて４０
分毎に堰を交換すると介在物レベルは低位に安定してお
り、効果が確認されたＯ 対象鋼稚　　（単位％）Figure 1 shows that in the conventional method, the amount of inclusions in the slab increases as the casting time becomes longer, and when the casting time exceeds 60 minutes, the through holes become clogged. It can be seen that the adsorption separation effect disappears. On the other hand, using the present invention, 40
When the weir was replaced every minute, the inclusion level remained stable at a low level, and the effect was confirmed.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来のタンディツシュ０−ａｔ示す正断＊ａ、
第２図は改良されたタンディツシュの一例を示す正断面
図、第３図は鋳造時間と一片内介在物指数との関係を示
すグラフである。 図中、６（ｌ堰、ａ１Ｆｉ貫通孔を示す。 特許出願人　　日本鋼ｗ株式会社 −日本碍子株式会社 発明者　大久蝋　益　太 同　　　　　　　　　川　　　上　　　公　　　成崗　
　　　　　　　　　細　　　１）　　義　　　部間　　
　　　　　　　水　　　上　　　秀　　　昭−Ｊ　　　
　　　　　　村　　　上　　　勝　　　彦陶　　　　　
　　　櫨　　　口　　　　　　　昇−持　　　１）　　
　　　　滋 −小笠原　孝　之 第１図 第３図 坐造時韻　（ｍｉｎ） 第２図Fig. 1 shows the conventional tanditsu 0-at normal cut*a,
FIG. 2 is a front sectional view showing an example of an improved tundish, and FIG. 3 is a graph showing the relationship between casting time and index of inclusions in one piece. In the figure, 6 (l weir, a1Fi through hole is shown. Patent applicant: Nippon Kou W Co., Ltd. - Nippon Insulator Co., Ltd. Inventor: Oku Romasu Taido Kawakami Ko Seigang
Detail 1) Gibema
Hideaki Mizukami-J
Katsuhiko Murakami pottery
Noboru Hajiguchi 1)
Shigeru - Takashi Ogasawara Figure 1 Figure 3 Zazo syllable (min) Figure 2

Claims (1)

【特許請求の範囲】 多数の貫通孔を有する堰を備えたタンディツシュを用い
る溶鋼の連続鋳造方法において、次式に従う時間を内で
＃Ｍｉ該堰を交換することを特徴とする溶鋼の連続鋳造
方法。 但し、ｒ　；堰の貫通孔直径 ム：−片断面積 ■ｃ；鋳造速度 ｔ　二層交換時間[Claims] A method for continuous casting of molten steel using a tundish equipped with a weir having a large number of through holes, characterized in that #Mi is replaced within a time according to the following formula: . However, r ; Diameter of the weir through-hole M : - Single cross-sectional area ■ c : Casting speed t Double-layer exchange time