JPS5913549A - Inclined type continuous casting method - Google Patents

Abstract

PURPOSE:To enable the production of a good ingot having good cleanliness and less segregation defects with good productivity by inclining the casting axis of a continuous casting device to the short side of a casting mold at a pecific angle of inclination to the perpendicular. CONSTITUTION:An ingot 5 flowed out from a casting mold 1 in continuous casting is drawn out in a horizontal direction while the same is inclined with straight part and a curved part. The casting axis of the mold 1 and the wall surfaces on the short side of the mold are provided so as to have an angle theta of inclination (20 deg.<=theta<=60 deg., more preferably, 30 deg.<=theta<=45 deg.) from the perpendicular line. The inclusions in the molten steel flowed out of a nozzle 2 try to float upward at a floating velocity VU, but the component of force VS is generated by the velocity VD in the drawing direction of the ingot 5. The inclusions are moved by said force to the short side on the inclined top surface side of the ingot 5, and are captured and accumulated mainly at the solidification boundary of the ingot on the top surface side, whereby the cleanliness of the ingot 5 on the lower short side is improved.

Description

【発明の詳細な説明】 本発明は清浄度の良い、偏析性欠陥の少い良鋳片を生産
性良く製造し得る溶鋼の傾斜型連続鋳造装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inclined continuous casting apparatus for molten steel that can produce high-quality cast slabs with good cleanliness and few segregation defects with high productivity.

近年、世界的な規模において省資源、省エネルギー、省
力化の観点から連続鋳造の適用拡大が進行しつつある。In recent years, the application of continuous casting has been expanding on a global scale from the viewpoints of resource saving, energy saving, and labor saving.

連鋳比率の増１犬と適用鋼種が高級調布拡大されるにつ
れて生ずる品質上の問題点として非金属介在物の問題が
生じた。非金属介在物（以下単に、介在物という。）の
問題は連続鋳造装置による鋳片の量産が開始された時か
ら本質的にかかえて来た問題きも言えるものである。即
ち、普通造塊法に於ては鋳型に溶鋼を注入した後の静置
時間を充分に取れるので微小な介在物も、鋼塊頭部に浮
上しつくしてしまい以降の分塊圧延で鋼塊頭部は切捨て
られるので充分清浄な鋼片を得ることが出来る。しかる
に連続鋳造法は厳密な意味での静止浴ではなく或速度で
鋳片が下方に引抜かれている状態に於て鋳型に溶鋼を注
入しているのであるから微小な介在物の浮」二分配の点
で本来大きな制約を受けている。脱酸生成物、即ち介在
物の浮上分離は一般に静止浴ではストークスの法則に従
うとされている。この法則によると介在物の浮」二速度
は下記（１）式の如くなることが知られている。As the continuous casting ratio increased and the range of applicable steel types expanded, the problem of non-metallic inclusions arose as a quality problem. The problem of non-metallic inclusions (hereinafter simply referred to as inclusions) can be said to be a problem that has essentially existed since the beginning of mass production of slabs using continuous casting equipment. In other words, in the ordinary ingot-forming method, sufficient standing time is allowed after pouring molten steel into the mold, so that even minute inclusions float to the top of the ingot and are removed during subsequent blooming. Since the head is cut off, a sufficiently clean piece of steel can be obtained. However, the continuous casting method is not a static bath in the strict sense of the word, but rather the molten steel is injected into the mold while the slab is being drawn downward at a certain speed. It is inherently subject to major constraints. It is generally believed that flotation separation of deoxidized products, ie, inclusions, follows Stokes' law in a static bath. According to this law, it is known that the floating velocity of inclusions is expressed by the following equation (1).

（ただし、■・、・介在物の浮上速度、Ｄ・−介在物の
粒子の直径、（ρ１．Ａ−ρＳ）・・・溶鋼と介在物の
密度差、η・・−・流体の粘性係数とする。）（２）式
に示す如く非金属介在物の浮上速度は介在物の粒子の直
径の２乗に比例するから、連鋳片の引抜速度より小さな
浮上速度の微小な非金属介在物（は連鋳片内に捕捉され
た１寸引抜かれることになる。(However, ■・・・Flying speed of inclusion, D・−Diameter of particle of inclusion, (ρ1.A−ρS)・・・・Difference in density between molten steel and inclusion, η・・・Viscosity coefficient of fluid ) As shown in equation (2), the floating speed of nonmetallic inclusions is proportional to the square of the particle diameter of the inclusion, so the floating speed of minute nonmetallic inclusions is smaller than the drawing speed of the continuous slab. (The 1 inch captured in the continuous slab will be pulled out.

介在物としては、ライムライト（ＣａＯ・Ａｆｆｉ２０
５　）系、７　／ｌ／　ミナ（Ａｆｆ２０３　）系、シ
リケート（ＪＯ２）系などがあり、これらは、たとえば
軽炉スラグが出鋼時に取鍋内に流出し、溶鋼中に微細に
懸濁したものが、溶鋼中の八λによって還元されながら
脱酸生成物のＡｐ２０３と凝集生成し、あるいは、脱酸
生成物以外に、出鋼から連続鋳造工程の間で溶鋼中の八
２が酸化されて生成した再酸化生成物であるＡＰ２０３
粒が凝集合体し生成すると考えられている。これらの介
在物が凝集する機構としては溶鋼中の介在物相互の凝集
による肥大化やタンプッシュノズル内壁に介在物が付着
し凝集肥大化することが考えられる。これらの介在物が
存在することにより、たとえば近年、炭酸飲料鑵やエア
ゾール罐等の内圧罐として製造されるＤ１罐において、
ＤＩ罐成形後罐端部をフランジ加工する際に罐端部が割
れるいわゆるフランジ割れ現象が発生し、その対策が要
望されている。７ランジ割れを生ずる介在物の寸法（ｒ
Ｊ−５０ｔｔｍφ以上であるとされている。又、その他
の各種製品欠陥に影響する介在物の下限サイズはＵＯＥ
　（大径溶接管）やＥＲＷ（電縫管）などのパイプの超
音波探傷欠陥の場合で２００μｍ程度、ブリキの表面欠
陥として知られるスリバー、ブローホールの場合で４０
０〜５００μｍ　８　ｔｌｌｊである。各種製品欠陥に
影響する介在物の下限サイズと介在′吻密度との関係を
第１図に示す。As inclusions, limelight (CaO・Affi20
5) type, 7/l/mina (Aff203) type, silicate (JO2) type, etc. These are, for example, light furnace slag that flows into the ladle during tapping and becomes finely suspended in molten steel. is reduced by 8λ in the molten steel and agglomerates with the deoxidation product Ap203, or in addition to the deoxidation product, 82 in the molten steel is oxidized and produced during the continuous casting process from tapping to the continuous casting process. AP203, the reoxidation product
It is thought that it is formed by agglomeration of grains. Possible mechanisms for the agglomeration of these inclusions include coagulation of inclusions in molten steel, resulting in enlargement, and inclusions adhering to the inner wall of the tump push nozzle, resulting in agglomeration and enlargement. Due to the presence of these inclusions, for example, in recent years, D1 cans manufactured as internal pressure cans such as carbonated beverage cans and aerosol cans,
When the end of the can is flanged after forming the DI can, a so-called flange cracking phenomenon occurs in which the end of the can breaks, and countermeasures against this phenomenon are desired. 7 Dimensions of inclusions that cause lunge cracks (r
It is said that it is J-50ttmφ or more. In addition, the minimum size of inclusions that affect various other product defects is UOE.
In the case of ultrasonic flaw detection of pipes such as (large-diameter welded pipes) and ERW (electronic resistance welded pipes), it is about 200 μm, and in the case of slivers and blowholes, which are known as surface defects on tinplate, it is about 40 μm.
0 to 500 μm 8 tllj. Figure 1 shows the relationship between the minimum size of inclusions that affect various product defects and the density of inclusions.

又、介在物として、ＭｎＳ系介在物ｉ０．０１重量％Ｓ
以上含有すると溶接構造物において、ラメラ−ティアと
いわれる溶接部の板厚方向に作用する引張応力によって
鋼板表面に平行に進展した剥離状の割れが発生し、その
対策が望才れている。In addition, as inclusions, MnS-based inclusions i0.01% by weight S
If the above content is present, in welded structures, peel-like cracks called lamellar tears that develop parallel to the steel plate surface due to tensile stress acting in the thickness direction of the welded portion occur, and a countermeasure against this problem is desired.

この他、偏析性欠陥として、溶鋼静圧によるバルジング
に起因して鋳片中心部の凝固組織が偏析するいわゆる中
心偏析も問題である。又、凝固収縮時に鋳片中心部に収
縮孔であるセンタボロンティが生じ、ボロンティイの多
い中心部では水素の集積が認められ、中心部にトラップ
された水素は中心偏析と複合して製品での水素割れを起
し、超音波欠陥の原因となることがあり問題である。In addition, so-called center segregation, in which the solidified structure at the center of the slab is segregated due to bulging due to static pressure of molten steel, is also a problem as a segregation defect. In addition, during solidification and shrinkage, center boron holes, which are shrinkage pores, are formed in the center of the slab, and hydrogen is observed to accumulate in the center where there are many boron holes. This is a problem as it may cause hydrogen cracking and cause ultrasonic defects.

一方、連鋳設備としては、鋳造軸が鉛直線であることを
特徴とする実用化された鋼の連鋳機としては最も古い型
式である垂直型と、鋳造軸が彎曲していることを特徴と
し、鋳型は内面がこの彎曲に対応した彎曲面を有する彎
曲鋳型である、現在連鋳機の主流をなす型式であし、最
も多く採用されている曲げ型（彎曲型）と、鋳造軸が鉛
直部から彎曲部へ移行した後矯直されて水平方向へ引出
される型式であり、垂直型と彎曲型とを折衷した形とな
っている垂直曲げ型（垂直部を有する彎曲型）とがある
。On the other hand, as for continuous casting equipment, there are two types: vertical type, which is the oldest type of commercially available continuous casting machine for steel, which is characterized by a vertical casting axis, and the vertical type, which is characterized by a curved casting axis. The mold is a curved mold whose inner surface has a curved surface corresponding to this curvature.This is the currently mainstream type of continuous casting machine, and the most commonly used type is the bent type (curved type), and the casting axis is vertical. This type is a type that is straightened after moving from a section to a curved section and then pulled out in the horizontal direction, and there is a vertical bending type (curved type with a vertical section) that is a mixture of the vertical type and the curved type. .

第２図に（ａ）垂直型、（ｂ）曲げ型、及び（Ｃ）垂直
曲げ型の立面説明図を示した。鋳型工よシ鋳片５が（ａ
）にあっては直線状に抜き出される。溶鋼の静圧が機高
と共に高くなるので、この面よゆ鋳造速度が制限され、
生産性に限界があるが、介在物は鋳片の厚み中央部を中
心に均等に分布するので拘利である。（ｂ）にあっては
鋳型ｌより鋳片５が半径Ｒの円弧に沿って移行してから
水平方向へ矯直されて引き出される。曲げ型（彎曲型）
連鋳機は垂直型と比較すると機高（Ｈ）も低くなり溶鋼
静圧も緩和されるので鋳造速度を増すことも可能となり
生産性に関しては垂直型よりもはるかに優れている。又
溶鋼静圧が緩和される為、鋳片が溶鋼静圧により膨れる
バルジング量が小さく、割れ、偏析などの面で鋳片の品
質上利点を有するものであるが、一方介在物の面では鋳
片の天測（上面側）ｌ／４〜］１５位置に集積する酸化
物系の介在物がある。FIG. 2 shows an elevation view of (a) a vertical type, (b) a bending type, and (C) a vertical bending type. The foundry worker saw that the slab 5 was (a
), it is extracted in a straight line. Since the static pressure of molten steel increases with machine height, the casting speed is limited by this surface.
Although there is a limit to productivity, inclusions are evenly distributed around the center of the thickness of the slab, so it is a problem. In (b), the slab 5 moves from the mold l along an arc of radius R, and then is straightened in the horizontal direction and pulled out. Bending type (curved type)
Continuous casting machines have a lower machine height (H) than the vertical type, and the static pressure of molten steel is alleviated, so it is possible to increase the casting speed, and it is far superior to the vertical type in terms of productivity. In addition, since the static pressure of molten steel is relaxed, the amount of bulging caused by the static pressure of molten steel is small, which has advantages in terms of quality of the slab in terms of cracking and segregation, but on the other hand, in terms of inclusions, There are oxide-based inclusions accumulated at 1/4 to 15 positions on the top surface side of the piece.

ここで介在物が鋳片の天側に集積する様子を第３図をも
って説明する。即ちタンプツシ−下方の浸漬ノズル２か
ら鋳型ｌに流下した溶鋼流４はメニスカスから約４ｍ以
上も深く介在物を持ちこみ緩慢域を形成する。緩慢域に
持ちとｉ！れた介在物はストークスの浮上速度ＶＵで鉛
直方向に浮」ニせんとするが鋳片は彎曲部の切線方向に
速度ＶＤにて引抜かり、るから実際の介在物の運動方向
及び速度はＶＵとＶＤの合力ＶＳとなる。かくして緩慢
域に持ち込まれた介在物は移動速度ｖｓにて該鋳片の上
面側の凝固界面に移動し、該緩慢域では凝固界面に於け
る溶鋼の流動が弱くなっているので、移動して来た介在
物は溶鋼で洗われることなく、凝固界面に捕捉され、そ
の結果介在物が鋳片厚みの約１／４部分（上面側）に集
積し、凝固シェル３を形成する。Here, the manner in which inclusions accumulate on the top side of the slab will be explained with reference to FIG. 3. That is, the molten steel flow 4 that has flowed down from the immersion nozzle 2 below the tamp seal into the mold 1 carries inclusions deeper than about 4 m from the meniscus, forming a sluggish region. Hold it in the slow zone! The inclusions are assumed to float vertically at the Stokes floating speed VU, but the slab is pulled out in the tangential direction of the curve at a speed VD, so the actual direction and speed of the inclusions' movement are VU. The resultant force of and VD is VS. In this way, the inclusions brought into the slow region move to the solidification interface on the upper surface side of the slab at the moving speed vs. In the slow region, the flow of molten steel at the solidification interface is weaker, so the inclusions move. The inclusions that have arrived are captured at the solidification interface without being washed away by the molten steel, and as a result, the inclusions accumulate in about 1/4 of the thickness of the slab (on the upper surface side) and form a solidification shell 3.

（ｃ）は垂直型と彎曲型とを折衷した形となっている。(c) has a shape that is a compromise between a vertical type and a curved type.

鋳型の鋳造軸は鉛直であり、曲げ型（彎曲型）のような
彎曲鋳型に関する複雑さはなくなる。垂直部を有するだ
け機高（１（）が高くなりその分溶鋼静圧が高くなる欠
点を有する。他方介在物の面では曲げ型（彎曲型）連鋳
機のそれに比較して大幅に減少し、介在物粒径で約１／
１０−１／２０になり、又曲げ型（彎曲型）連鋳機に発
生した１／４〜１１５厚みの介在物集積帯も完全に消滅
しており、介在物の面からの垂直部の効果が極めて犬で
あるとの知見がある。The casting axis of the mold is vertical, eliminating the complications associated with curved molds such as curved molds. The machine height (1()) increases due to the vertical section, which increases the static pressure of the molten steel.On the other hand, the inclusions are significantly reduced compared to that of a bending type (curved type) continuous casting machine. , the inclusion particle size is approximately 1/
10-1/20, and the inclusion accumulation zone with a thickness of 1/4 to 115 that occurred in the bending type (curved type) continuous casting machine has completely disappeared, and the effect of the vertical part from the surface of the inclusions. There is knowledge that it is extremely dog-like.

以上説明したように、従来の連続鋳造装置においては、
何れにしても鋳片のバルジングは中心偏析を悪化させる
から、該バルジングに最も影響の大きい溶鋼静圧ばでき
るだけ小さくする必要があるが従来の介在物の浮上除去
対策は何れも連鋳機の機高（Ｈ）が高くなり溶鋼静圧は
増加する方向にあるので、この点より考えても介在物対
策と中心偏析対策とは互に相反する関係にあり両者を同
時に満足させない。As explained above, in conventional continuous casting equipment,
In any case, bulging of the slab aggravates center segregation, so the static pressure of molten steel, which has the greatest effect on bulging, must be minimized as much as possible. As the height (H) increases, the static pressure of molten steel tends to increase, so from this point of view, measures against inclusions and measures against center segregation are in a mutually contradictory relationship, and both cannot be satisfied at the same time.

本発明は、介在物対策と中心偏析対策とを同時に満足さ
せうる連続鋳造装置で、本発明装置を使用することによ
り、清浄度の良い、偏析性欠陥の少い良鋳片を生産性良
く製造することができる。The present invention is a continuous casting device that can simultaneously satisfy the measures against inclusions and center segregation. By using the device of the present invention, high-quality cast slabs with good cleanliness and few segregation defects can be manufactured with high productivity. can do.

すなわち、本発明は溶鋼を連続鋳造する装置において、
鋳造軸が、鋳型短辺側へ鉛直面に対して角度θ傾斜して
いることを特徴とする。以下図面を用いて本発明の詳細
な説明する。That is, the present invention provides an apparatus for continuously casting molten steel,
It is characterized in that the casting axis is inclined at an angle θ with respect to the vertical plane toward the short side of the mold. The present invention will be described in detail below using the drawings.

第４図に本発明傾斜直線曲げ型連鋳機の概略説明図を示
す。（ａ）図は、鋳型１より流出した鋳片、５が直線部
分、曲げ部分を経由して、傾斜しながら水平方向に引き
出されてゆく状態を示している。FIG. 4 shows a schematic illustration of the inclined linear bending type continuous casting machine of the present invention. The figure (a) shows a state in which the slab 5 flowing out of the mold 1 is drawn out in the horizontal direction while being inclined through a straight section and a bent section.

（ｂ）図は鋳型１の長辺方向から見た側面図で、鋳造軸
及び鋳型短辺の壁面が鉛直線よりθの傾斜角度を有して
いる。溶鋼は矢印の如くノズル２より流出する。垂直部
において、介在物は矢印の如く上方に浮上速度ＶＵで浮
上せんとするが、実際の運動方向及び速度は鋳片の引出
方向の速度ＶＤとの合力ＶＳとなる。（Ｃ）図は、Ａ　
−Ａ方向側面より見ブこ図である。(b) is a side view of the mold 1 viewed from the long side direction, in which the casting axis and the wall surface of the short side of the mold have an inclination angle of θ from the vertical line. Molten steel flows out from the nozzle 2 as shown by the arrow. In the vertical part, the inclusions try to float upward as indicated by the arrow at a floating velocity VU, but the actual direction and velocity of movement is the resultant force VS of the velocity VD in the drawing direction of the slab. (C) The figure is A
- It is a side view in the A direction.

第５図０１傾斜型垂直曲げ型連鋳機の鋳型Ｊ近傍の説明
図で、（ａ）は平面図、（ｂ）は鋳型長辺方向からみた
立面断面図、（Ｃ）は鋳型短辺方向からみだ立面断面図
である。又、第６図は同連鋳機の水平方向へ引き出され
る部分の鋳片支持を説明する立面図である。第５図にお
いて鋳型１は矩形状であり、短辺側壁面が鉛直面に対し
て角度θ傾斜し、溶鋼はノズル２より鋳型内へ流下し、
鋳片５となって引き出される。第５図を構成する本発明
装置は、溶鋼を連続鋳造するに際し、鋳造軸が傾斜直線
部分と彎曲部分とから構成されており該直線部分と彎曲
部分とを含む鋳造軸が鉛直線に対して角度θ傾斜してい
ることを特徴とする。本発明の連鋳機の鋳型直下の直線
部分を鋳片の長辺側より見る時鋳造軸が鉛直線に対して
角度θだけ傾斜しているがこｈはスラブ状鋳片の長辺側
は垂直であり、短辺側が角度θだけ傾斜していることを
意味する。Fig. 5 is an explanatory diagram of the vicinity of the mold J of the 01 inclined vertical bending type continuous casting machine, (a) is a plan view, (b) is an elevational sectional view seen from the long side direction of the mold, and (C) is the short side of the mold. It is an elevational cross-sectional view from the direction. Further, FIG. 6 is an elevational view illustrating the support of the slab in the horizontally drawn portion of the continuous casting machine. In FIG. 5, the mold 1 has a rectangular shape, the short side wall surface is inclined at an angle θ with respect to the vertical plane, and the molten steel flows into the mold from the nozzle 2.
It becomes the slab 5 and is drawn out. In the apparatus of the present invention shown in FIG. 5, when continuously casting molten steel, the casting axis is composed of an inclined straight part and a curved part, and the casting axis including the straight part and the curved part is relative to a vertical line. It is characterized by being inclined at an angle θ. When looking at the straight section directly under the mold of the continuous casting machine of the present invention from the long side of the slab, the casting axis is inclined at an angle θ with respect to the vertical line. It is vertical, meaning that the short side is inclined by an angle θ.

該鋳型直下の直線部分を鋳片の短辺側より見ると鋳造軸
は垂直である為に注入流によって持ち込豊れた介在物は
鉛直上方に浮」ニすることができる。When looking at the straight section directly under the mold from the short side of the slab, the casting axis is vertical, so inclusions brought in by the pouring flow can float vertically upward.

本発明によね、は介在物（は曲げ型（彎曲型）連鋳機で
述べた如く、長辺側の凝固／エルに捕捉され集積するこ
とはない。実際には介在物の浮上速度ＶＵと鋳片の引抜
速度ＶＤとの合力ＶＳにより介在物は鋳片の傾斜上面側
の短辺に移動して主として上面側の短片の凝固界面に捕
捉され集積される。According to the present invention, inclusions (as described in the case of the bending type (curved type) continuous casting machine) are not captured and accumulated by the solidification/el on the long side.Actually, the floating speed VU of the inclusions The inclusions move to the short side of the sloped upper surface of the slab due to the resultant force VS with the drawing speed VD of the slab, and are captured and accumulated mainly at the solidification interface of the short piece on the upper surface side.

鋳造軸の鉛直線よりの傾斜角度θは、２００≦θ≦６０
０とするが、３００≦θ≦４５０が好寸しい。The inclination angle θ of the casting axis from the vertical line is 200≦θ≦60
0, but preferably 300≦θ≦450.

θが３０’未満の時には、機高（Ｈ）があ寸り低減しな
いので溶鋼静圧もあまり低減せず、設備が複雑化する割
には効果が小さい。又θが４５°より犬の時には、垂直
部の長さくｈ）が短くなり過ぎること、及び矯直後の鋳
片の支持機構が設備的に高価になってし甘う割には効果
が小さくなる。When θ is less than 30', the machine height (H) is not reduced significantly, so the static pressure of molten steel is not reduced much, and the effect is small even though the equipment becomes complicated. In addition, when θ is smaller than 45°, the length of the vertical part (h) becomes too short, and the supporting mechanism for the cast slab after straightening becomes expensive in terms of equipment, and the effect becomes small. .

本発明によｈ−は鋳片の引抜速度より小さな浮上速度の
微小な介在物は連鋳片内に捕捉された１寸引抜かれるこ
とに就では従来と変らないがその分布状態に方向性を生
じ、介在物は天側（上側）短辺側へ向って移動濃化し地
側（下側）短辺側の切片の清浄度が非常に良くなる′持
０徴を有する。又大型介在物は天側（上側）短辺側凝固
界面に捕捉集積され、るが曲げ型（何曲型）連鋳機の場
合鋳片の上面側に介在物の集積帯が生じた場合と比較す
ると短辺側への集積の為に集積幅も極めて狭い上に最終
製品の板類の形態から見て介在物の集積帯が鋳片の片側
短辺のみに限定されることは極めて有利である。According to the present invention, minute inclusions with a floating speed lower than the drawing speed of the slab are pulled out by one inch captured in the continuous slab, which is the same as in the conventional method, but the distribution state has a directionality. The inclusions move and become concentrated toward the top (upper) short side, and the cleanliness of the section on the bottom (lower) short side becomes very good. In addition, large inclusions are captured and accumulated at the solidification interface on the top (top) short side, whereas in the case of a bending type (multi-curved) continuous casting machine, an accumulation zone of inclusions occurs on the top side of the slab. In comparison, the accumulation width is extremely narrow due to the accumulation on the short side, and in view of the form of the final product plate, it is extremely advantageous that the inclusion accumulation zone is limited to only one short side of the slab. be.

本発明は中心偏析、センターポロシティ等の偏析性欠陥
の面でも優れた特徴を有する。従来の曲げ型（彎曲型）
連鋳機、及び垂直曲げ型連鋳機は何れもスラブ鋳片に於
ては最終凝固は矩形断面の水平凝固となる為、鋳片厚み
中心部分に水平線状に中心偏析及びセンターポロシティ
等を生ずる。The present invention also has excellent features in terms of segregation defects such as center segregation and center porosity. Conventional bending type (curved type)
In both continuous casting machines and vertical bending type continuous casting machines, the final solidification of slab slabs is horizontal solidification of a rectangular cross section, which causes center segregation and center porosity in a horizontal line at the center of the thickness of the slab. .

此れは最終凝固位置に濃化溶鋼が捕捉される為に必然的
に生じる現象であり、等軸品が増加する程中心偏析は軽
減するから低温鋳造の他にＲＥＭ添加、鋼線添加、電磁
攪拌などが行ばれるが矩形断面が最終凝固を水平位置で
行うと言う本質上生じる現象である。This is a phenomenon that inevitably occurs because concentrated molten steel is trapped in the final solidification position, and as the number of equiaxed products increases, center segregation will be reduced. This is a phenomenon that essentially occurs because the rectangular cross section causes the final solidification to take place in a horizontal position, although stirring is performed.

ここで第６図について説明すると、軸受７．７によって
支持されたロール６．６の間をスラブ鋳片５が水平方向
に引出さり、、スラブ鋳片５の最終凝固は矩形断面が水
平線に対して角度θだけ傾斜した状態で行う事を特徴と
する。かくすることにより鋳片内の未凝固部分ｌＯも同
様に傾斜した状態となる為、未凝固部分の溶鋼の比重分
離が可能となる。Now, referring to FIG. 6, the slab slab 5 is pulled out in the horizontal direction between rolls 6.6 supported by bearings 7.7, and the final solidification of the slab slab 5 is such that the rectangular cross section is aligned with the horizontal line. It is characterized in that it is performed in a state where it is tilted by an angle θ. By doing this, the unsolidified portion lO in the slab is also in a tilted state, so that the specific gravity separation of the molten steel in the unsolidified portion becomes possible.

即ち未凝固部分の溶鋼中比重の犬なる部分が下方へ、比
重の小なる部分が上方へと分離される結果、先述の介在
物が多く捕捉された側の鋳片には偏析性欠陥も多く濃縮
され、他方介在物の少ない清浄度の良い側の鋳片には偏
析性欠陥の非常に少い良鋳片となる特徴を有する。In other words, as a result of the unsolidified portion of the molten steel having a high specific gravity being separated downward and the portion having a low specific gravity being separated upward, there are many segregation defects in the slab on the side where many of the aforementioned inclusions have been captured. Concentrated slabs with good cleanliness and fewer inclusions have the characteristic of being good slabs with very few segregation defects.

元来連鋳方式は普通造塊方式と比較するに引抜移動中の
急速凝固と言う本質から来る特徴を有する為、成程度の
介在物や偏析性成分も鋳片の引抜移動と共に同伴しつつ
、鋳片内で介在物ｆｌ　７Ｎ固シエルに捕捉集積したり
偏析性成分は最終凝固部分で濃縮すると言う特徴上、鋳
片内にこれらの欠陥を分散して包含し易い特性を有する
。此の点が鐙通造塊方式では注入完了后充分静置時間を
置くことにより介在物や偏析性成分を充分に比重分離し
て鋼塊頭部に該欠陥部分を集積して分塊圧延後切捨てて
除去可能な点と大いに異なるものである。Originally, the continuous casting method has the characteristic of rapid solidification during the drawing movement compared to the ordinary ingot making method, so a certain amount of inclusions and segregated components are accompanied by the drawing movement of the slab. Because inclusions are captured and accumulated in the 7N solid shell within the slab, and segregated components are concentrated in the final solidified portion, these defects are easily dispersed and contained within the slab. In the stirrup through ingot making method, inclusions and segregated components are sufficiently separated by specific gravity by allowing sufficient standing time after completion of pouring, and the defective parts are accumulated at the head of the steel ingot after blooming. This is very different from the fact that it can be cut off and removed.

本発明は普通造塊方式等が有する介在物や偏析性成分の
比重分離の思想を連鋳方式に適用したものである。The present invention applies the concept of specific gravity separation of inclusions and segregated components, which is found in ordinary ingot making methods, to a continuous casting method.

第７〜８図に此の思想を更に発展させたものを示す。即
ち従来は矩形鋳型で鋳造していたものを天側（上側）短
辺を長く、地側（下側）短辺を短く設定した梯形鋳型で
鋳造することを特徴とする。Figures 7 and 8 show a further development of this idea. That is, what is conventionally cast using a rectangular mold is now cast using an elongated mold with a longer top (upper) short side and a shorter bottom (lower) short side.

各図の記号は第５〜６図と同様である。かくすることに
より鋳片は鋳型直下の直線部では鉛直線に対して角度θ
傾斜しだ上広状鋳片となり介在物の浮上分離に極めて好
ましい。又、最終凝固部位近傍に於ては第８（ａ）図の
如く梯形鋳片は傾斜した上下のテーパーロールで移送さ
れつつ冷却されて凝固が進行する。かくして該梯形鋳片
は下側の短辺の短い方から凝固が完了する為鋳片の未凝
固部分は」二側の短辺の長い方に移行しかつ該未凝固部
分が傾斜している為濃縮溶鋼の比重分離が生ずる。The symbols in each figure are the same as in FIGS. 5 and 6. By doing this, the slab forms an angle θ with respect to the vertical line in the straight section directly under the mold.
It becomes a wide slab with an inclined ridge, which is extremely suitable for flotation and separation of inclusions. Further, in the vicinity of the final solidification site, the trapezoidal slab is cooled and solidified while being transported by upper and lower inclined tapered rolls, as shown in FIG. 8(a). In this way, since solidification of the trapezoid slab is completed from the short side of the lower short side, the unsolidified part of the slab moves to the long side of the second short side, and the unsolidified part is inclined. Specific gravity separation of concentrated molten steel occurs.

次に第８（ｂ）図に示す如く該梯形鋳片は圧下ロール９
に依って軽圧下されて矩形鋳片となる。此の際の圧下ロ
ールに依る軽圧下は、主として梯形鋳片の未凝固部分を
有する上側の短辺の長い方に集中されるので、軽圧下に
よる該未凝固部分の濃縮溶鋼が絞り出されて鋳片内質は
著しく改質される。Next, as shown in FIG. 8(b), the trapezoidal slab is rolled onto a rolling roll 9
It is lightly rolled down into a rectangular slab. In this case, the light reduction by the reduction roll is mainly concentrated on the longer upper short side of the trapezoidal slab, which has the unsolidified part, so that the concentrated molten steel in the unsolidified part is squeezed out and becomes the slab. The endoplasm is significantly modified.

しかしながら本発明により製造される連鋳片（１、介在
物及び偏析成分を鋳片天側（上側）短辺側に集約して、
鋳片地側（下側）短辺側に極めて清浄度の高いものにし
た鋳片幅方向に方向性を有するものである。従って品質
用途別に鋳片幅分割して振り当てることが望ましい。However, the continuous cast slab produced by the present invention (1, inclusions and segregated components are concentrated on the short side of the slab top side (upper side),
It has a directionality in the width direction of the slab with extremely high cleanliness on the short side (lower side) of the slab. Therefore, it is desirable to divide the slab width and allocate it to each quality application.

第９図は此の為の鋳片幅分割の為の溝形成ロール１１を
示す。FIG. 9 shows a groove forming roll 11 for dividing the slab width for this purpose.

第１０図は鋳片５が水平に対して角度０傾斜、せる片側
フランジロール６により移送させることを示す。FIG. 10 shows that the slab 5 is transported by a one-sided flange roll 6 tilted at an angle of 0 with respect to the horizontal.

第１１図は鋳片、５が採尺切断後水平ロール６によりり
移送される。FIG. 11 shows a slab 5 that is cut to length and then transported by a horizontal roll 6.

以上、傾斜直線曲げ型連鋳機について、図面をもって説
明したが、若し鋳片の介在物性の欠陥より偏析性の欠陥
をより重要視すべき品質設計の時には、鋳型短辺側壁面
が鉛直面に対して角度θ傾斜していることを特徴とする
傾斜型何曲式連続鋳造装置が好寸しい（実施例２）。こ
の場合、機高（Ｈ）は直線部分を有しない為傾斜直線曲
げ型連続鋳造設備より更に低く出来るので溶鋼静圧も小
さくなり鋳片のバルジングが小さくなるので鋳造速度を
」二けることが出来る。又、梯形鋳込みと鋳片の傾斜支
持とによる未凝固溶鋼の比重分離効果及び最終凝固位置
近傍における鋳片の軽圧下との相乗効果によって鋳片の
中心偏析の極めて少ないものを得ることが出来る。The inclined linear bending type continuous casting machine has been explained above using drawings. However, when quality design requires that segregation defects be more important than defects caused by inclusions in slabs, it is necessary to An inclined type multi-curved continuous casting apparatus characterized by being inclined at an angle θ with respect to the casting apparatus is suitable (Example 2). In this case, since the machine height (H) does not have a straight part, it can be lowered even lower than that of an inclined straight bending type continuous casting equipment, which reduces the static pressure of the molten steel and reduces the bulging of the slab, making it possible to reduce the casting speed. . Further, due to the synergistic effect of the specific gravity separation effect of the unsolidified molten steel due to the trapezoidal casting and the inclined support of the slab and the light reduction of the slab near the final solidification position, it is possible to obtain extremely low center segregation of the slab.

比較例１ 下記条件にて曲げ型（彎曲型）連鋳−機（第２（ｂ）図
）を用いて鋳造した。Comparative Example 1 Casting was performed using a bending type (curved type) continuous casting machine (Fig. 2(b)) under the following conditions.

彎曲半径　　　Ｒ＝　１．０，５００略・機高　　　　
　Ｈ＝　１０，３０Ｃ）　ｗｔｂ溶鋼静圧　　　７．３
５し／ｃｍ２ スラブ鋳片　　２５０　Ｘ　１５００脇鋳造速度　　　
１．２　ｍ　／　ｍ　ｉｎ天側（上面側）長辺の鋳片厚
みの約５０ｍｍ（１１５）の部分に介在物の集積を見た
。Curving radius R = 1.0,500 approx. Machine height
H= 10,30C) wtb molten steel static pressure 7.3
5/cm2 Slab slab 250 x 1500 side casting speed
Accumulation of inclusions was observed in a portion of approximately 50 mm (115) thick on the long side of the slab on the top side (upper surface side) of 1.2 m/min.

比較例２ 下記条件にて垂直曲げ型連鋳機（第２（Ｃ）図）を用い
て鋳造した。Comparative Example 2 Casting was performed using a vertical bending type continuous casting machine (Fig. 2(C)) under the following conditions.

垂直部高さ　　ｈ＝５，０００訳 彎曲半径　　　Ｒ１＝４０．Ｏ○○ｍＭＲ２＝２０，０
００皿 Ｒ３−＝１４，０ＯＣｌ＋１ Ｒ＝１０，３０ｏ　ｗｒｂ 機高　　　　　Ｈ＝　１５．．５００期・溶鋼静圧　　
　１０．Ｂ　５　Ｋ７ｅ　／ｃｍ２スラブ鋳片　　２５
０　Ｘ　１５０’Ｏ脇鋳造速度　　　０．８ｍ／ｍｉｎ 介在物は曲げ型（彎曲型）連鋳機の場合と比較して介在
物の粒径で約１７１０に減少し、天側（上面側）長辺の
厚み］／４〜１１５に発生していた介在物集積帯も消滅
した。曲げ型（９曲型）連鋳機に比較して機高（Ｈ）は
約２．２倍となり溶鋼静圧が犬きくなった為鋳片のバル
ジングが大きくなるので鋳造速度を下げて対処している
。その為生産性は約１／３低下し、中心偏析前で悪化し
た。Vertical height h=5,000, radius of curvature R1=40. O○○mMR2=20,0
00 plate R3-=14,0OCl+1 R=10,30o wrb Height H=15. ．． 500 period/molten steel static pressure
10. B 5 K7e /cm2 Slab slab 25
0 x 150'O side casting speed 0.8m/min The particle size of inclusions is reduced to about 1710 compared to the case of a bending type (curved type) continuous casting machine, and the top side (top side) length is The inclusion accumulation zone that had appeared between [side thickness]/4 and 115 also disappeared. The machine height (H) is about 2.2 times that of a bending type (9-curve type) continuous casting machine, and the static pressure of molten steel is much higher, so the bulging of the slab becomes larger, so we reduced the casting speed to deal with it. ing. As a result, productivity decreased by about 1/3 and worsened before center segregation.

実施例１ 下記条件にて傾斜直線曲げ型連鋳機（第４図）を用いて
鋳造した。Example 1 Casting was carried out using an inclined linear bending type continuous casting machine (Fig. 4) under the following conditions.

傾斜角度　　　θ−３００ 垂直部高さ　　ｈ二４，３３０皿 彎曲半径　　　Ｒ１＝４０，０００ＷＭＲ２＝＝２０，
０００　ｍＡ Ｒ３＝１４，０００Ｗａ Ｒ＝　１０，５００問。Inclination angle θ-300 Vertical height h2 4,330 Disc curvature radius R1=40,000WMR2==20,
000 mA R3=14,000Wa R= 10,500 questions.

機高　　　　　Ｈ＝　１３，４２３　ｍｒｒｂ溶鋼静圧
　　　９−４０　Ｋｙ　７ｃｍ”スラブ鋳片　　２５０
　Ｘ　２３００賜分割鋳片　　　２５ｔ、　Ｘ　１５０
０　Ｃ上側）賜２５０　Ｘ　８００　　（下側）賜 鋳造速度　　　　１．２　ｍ　／　ｍｊ　ｎ分割鋳片」
二側は普通磨鋼板振当て　（磨鋼板品種はクリヤー）、
分割鋳片下側はブリキ用に振当てを行った。特に分割鋳
片下側の清浄度の向上は著しく、曲げ型（彎曲型）連鋳
機と比較して粒径で約１／２０に減少し、垂直曲げ型連
鋳機と比較しても粒径で約１／２に減少した。長辺厚み
１／４〜１１５に発生していた介在物集積帯もない。Machine height H= 13,423 mrrb Molten steel static pressure 9-40 Ky 7cm” slab slab 250
X 2300 split slab 25t, X 150
0C Upper) Thickness 250 x 800 (Bottom) Thickness Casting speed 1.2 m / mj n-divided slab
The second side is a regular polished steel plate (the polished steel plate type is clear),
The lower side of the split slab was allocated for tinplate. In particular, the improvement in cleanliness at the bottom of the divided slabs is remarkable, with the particle size being reduced to about 1/20 compared to a bending type (curved) continuous casting machine, and even compared to a vertical bending type continuous casting machine. The diameter was reduced to about 1/2. There is no inclusion accumulation zone that occurs in the long side thickness of 1/4 to 115 mm.

実施例２ 下記条件にて傾斜曲げ型（彎曲型）連鋳機を用いて鋳造
した。Example 2 Casting was performed using an inclined bending type (curved type) continuous casting machine under the following conditions.

傾斜角度　　　　θ−３０゜ 彎曲半径　　　　Ｒ＝１０，５０Ｃ）腑・機高　　　　
　　Ｈ＝９，１００間 溶鋼静圧　　　　６．４０１＄　／ｃｒｎ”スラブ鋳片
　　　２５０　Ｘ　］、５００騙（（２５２／　２４８
）Ｘ　１５００梯形鋳込）鋳造速度　　　　１．４　ｍ
　／　ｍｉｎ介在物に関しては曲げ型（彎曲型）連鋳機
と略同−レベルであり天側（上面側）長辺の介在物集積
も略同じく発生した。機高（Ｈ）　ｌｒｉ曲は型連鋳機
より低くなり溶鋼静圧も小さくなり鋳片のバルジングが
小さくなるので鋳造速度を上げることが出来る。Inclination angle θ-30゜Curving radius R=10,50C) Aircraft height
H = 9,100 molten steel static pressure 6.401 $ / crn” Slab slab 250
)X 1500 trapezoid casting) Casting speed 1.4 m
/ min inclusions were at approximately the same level as the bent type (curved type) continuous casting machine, and the accumulation of inclusions on the long side of the top side (upper surface side) also occurred in approximately the same way. The machine height (H) is lower than that of a continuous mold casting machine, the static pressure of molten steel is also reduced, and the bulging of the slab is reduced, so the casting speed can be increased.

その為生産性は約１５９≦向上し梯形鋳込と軽圧下の効
果により亦鋳片の幅分割にょシ中心偏析、センターの面
で良好な鋳片を得ることが出来た。As a result, productivity improved by approximately 159≦, and due to the effects of trapezoidal casting and light reduction, slabs with good width division, center segregation, and center surface could be obtained.

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

第１図は鋳片的介在物分布を示す説明図である。 第２〜３図は従来技術を示す立面説明図である。 第４〜１１図は本発明実施例の原理説明図で、第５（ａ
）図、および第７（ａ）図は平面図、他は立面図である
。 １　・・鋳型、２　・　ノズル、３・・・凝固７エル、
４・、溶鋼、５・・−鋳片、６・、・　ロール、７　・
・軸受、８・−、テーパーロール、９　・−圧下ロール
、１０　　・・未凝固部分、１１・・　溝形成ロール。 特許出願人　新日本製鐵株式會社 代理人　　　弁理士　井上雅生 第１図 介在物の大台さＧμｍｒｒｌ−） 第２図 第６図 第７図 （Ｑ） （ｂ）　　　　　　　　（ｃ） 第８図 （ＣＩ） （ｂ） 第９図 （ 第月図FIG. 1 is an explanatory diagram showing the distribution of slab-like inclusions. 2 and 3 are explanatory elevational views showing the prior art. 4 to 11 are explanatory diagrams of the principle of the embodiment of the present invention, and the fifth (a)
) and FIG. 7(a) are plan views, and the others are elevation views. 1. Mold, 2. Nozzle, 3. Solidification 7L,
4. Molten steel, 5.--Slab, 6., Roll, 7.
- Bearing, 8 - Taper roll, 9 - Reduction roll, 10 - Unsolidified portion, 11 - Groove forming roll. Patent Applicant Nippon Steel Corporation Agent Patent Attorney Masao Inoue Figure 1 Large size of inclusion Gμmrrl-) Figure 2 Figure 6 Figure 7 (Q) (b) (c) Figure 8 (CI) ) (b) Figure 9 ( Month figure

Claims (7)

【特許請求の範囲】[Claims] （１）　　溶鋼を連続鋳造する装置において、鋳造軸が
、鋳型短辺側へ鉛直面に対して角度θ傾斜していること
を特徴とする傾斜型連続鋳造装置。(1) An inclined continuous casting apparatus for continuously casting molten steel, characterized in that the casting axis is inclined at an angle θ with respect to the vertical plane toward the short side of the mold. （２）鋳造軸が直線部分と彎曲部分とからなる特許請求
の範囲第（１）項記載の連続鋳造装置。(2) The continuous casting apparatus according to claim (1), wherein the casting shaft includes a straight portion and a curved portion. （３）　　鋳造軸が直線部分を含まず彎曲部分のみから
なる特許請求の範囲第（１）項記載の連続鋳造装置。(3) The continuous casting apparatus according to claim (1), wherein the casting shaft does not include a straight portion but only a curved portion. （４）角度θが２０°≦θ≦６００であることを特徴と
する特許請求の範囲第（１）、（２）又は（３）項記載
の連続鋳造装置。(4) The continuous casting apparatus according to claim 1, (2) or (3), wherein the angle θ is 20°≦θ≦600. （５）　　鋳片傾斜の天側（上側）短辺全地側（下側）
短辺より長く設定した梯形鋳型を使用したことを特徴と
する特許請求の範囲第（１）　、　（２）又ハ（３）項
記載の連続鋳造装置。(5) Top side (upper side) of slanted slab, entire short side (lower side)
A continuous casting apparatus according to claim 1, 2, or 3, characterized in that a trapezoidal mold having a length longer than its short sides is used. （６）鋳片最終凝固位置近傍で傾斜支持したまま軽圧下
することを特徴とする特許請求の範囲第（１）、（２）
又は（３）項記載の連続鋳造装置。(6) Claims (1) and (2) characterized in that the slab is lightly rolled down while being tilted and supported near the final solidification position.
Or the continuous casting device described in (3). （７）　　鋳片幅分割装置を連設したことを特徴とする
特許請求の範囲第（１）　、　（２）又は（３）項記載
の連続鋳造装置。(7) The continuous casting apparatus according to claim 1, (2) or (3), characterized in that a slab width dividing device is provided in series.