JPH11309552A - Production of continuously cast round billet and producing apparatus thereof - Google Patents
Production of continuously cast round billet and producing apparatus thereofInfo
- Publication number
- JPH11309552A JPH11309552A JP11361898A JP11361898A JPH11309552A JP H11309552 A JPH11309552 A JP H11309552A JP 11361898 A JP11361898 A JP 11361898A JP 11361898 A JP11361898 A JP 11361898A JP H11309552 A JPH11309552 A JP H11309552A
- Authority
- JP
- Japan
- Prior art keywords
- casting
- unsolidified
- roll
- solidification
- reduction
- 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.)
- Withdrawn
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- Metal Rolling (AREA)
- Continuous Casting (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、特に鋳込み速度の
変動時において、丸鋳片の中心部に発生する中心偏析や
センターポロシティなどの内質欠陥を低減させ、かつ、
真円度の高い丸鋳片を得る連続鋳造丸鋳片の製造方法と
その製造装置に関する。The present invention is intended to reduce internal defects such as center segregation and center porosity which occur in the center of a round slab, particularly when the casting speed fluctuates, and
The present invention relates to a method for producing a continuously cast round slab that obtains a round slab with high roundness, and an apparatus for producing the same.
【０００２】[0002]
【従来の技術】従来、シームレスパイプ製造用素材とし
ては、比較的大断面のブルームを連続鋳造により鋳造
し、該ブルームを分塊圧延して製造された丸ビレットが
用いられてきた。2. Description of the Related Art Conventionally, as a material for producing a seamless pipe, a round billet manufactured by casting a bloom having a relatively large cross section by continuous casting and subjecting the bloom to slab rolling has been used.
【０００３】近年、製造工程の合理化のため、分塊圧延
工程を省略し、連続鋳造した丸鋳片を直接的に製管する
方法が指向されている。しかし、連続鋳造された丸鋳片
は、中心偏析やセンターポロシティなどの内部欠陥を有
しており、分解圧延工程を省略すると、マンネスマン穿
孔時に該内部欠陥が起点となり、製管された粗管の内面
に疵が発生し、歩留まりの低下や疵手入れによる製造コ
ストの増大を招く。[0003] In recent years, in order to rationalize the manufacturing process, a method of directly omitting a continuously cast round cast piece without a slab rolling step has been proposed. However, continuously cast round slabs have internal defects such as center segregation and center porosity, and if the disassembly and rolling step is omitted, the internal defects become the starting point at the time of Mannesmann drilling, and the rough pipe that is formed A flaw is generated on the inner surface, which leads to a decrease in yield and an increase in manufacturing cost due to flaw care.
【０００４】連続鋳造鋳片の内部欠陥を改善する方法と
して、鋳造中の鋳片に圧下を加える方法が提案されてい
る。特開平７−２０４８１２号公報には、凝固完了前の
丸鋳片にフラットロールで軽圧下を加え、中心偏析およ
びセンターポロシティを改善する方法が提示されてい
る。しかし、Ｃｒ含有鋼や高炭素鋼は、中心偏析やセン
ターポロシティの発生領域が広く、軽圧下では中心偏析
やセンターポロシティの改善が充分でない。[0004] As a method of improving internal defects in a continuously cast slab, a method of applying a reduction to a slab during casting has been proposed. Japanese Unexamined Patent Publication No. Hei 7-204812 discloses a method of improving the center segregation and the center porosity by applying a gentle reduction with a flat roll to a round cast piece before solidification is completed. However, Cr-containing steels and high-carbon steels have a wide area where center segregation and center porosity occur, and the improvement of center segregation and center porosity is not sufficient under light pressure.
【０００５】特開平９−１７４２１２号公報には、凝固
完了前の丸鋳片に鞍型ロールで圧下を加え、内部割れの
発生を防止しながら中心偏析およびセンターポロシティ
を改善する方法が開示されている。しかし、一般的にセ
ンターポロシティは、一方向から変形を加え、扁平化す
ることにより小さな圧下率で圧着が可能であるが、鞍型
ロールでは、センターポロシティは、その径が小さくな
るものの扁平化しにくく、圧着させるには大きな圧下量
が必要となり、その結果、鋳片の真円度が悪化する。さ
らに、断面内変形に比べて鋳込み方向への変形が大きい
ため、鋳込み方向に作用する引張応力が大きくなり、鋳
片内部の凝固界面に割れが発生しやすい。Japanese Patent Application Laid-Open No. 9-174212 discloses a method for improving center segregation and center porosity while preventing the occurrence of internal cracks by applying rolling reduction to a round cast slab before solidification is completed. I have. However, in general, the center porosity can be deformed from one direction and flattened to enable crimping with a small reduction rate, but with saddle type rolls, the center porosity has a smaller diameter but is harder to flatten In addition, a large amount of reduction is required to perform pressure bonding, and as a result, the roundness of the cast slab deteriorates. Furthermore, since the deformation in the casting direction is larger than the deformation in the cross section, the tensile stress acting in the casting direction is increased, and cracks are easily generated at the solidification interface inside the slab.
【０００６】特開平９−２０１６０１号公報や特開平９
−２０１６０２号公報には、Ｃｒ含有鋼の中心偏析やセ
ンターポロシティを改善する方法として、凝固完了後の
丸鋳片にロールによる圧下を加えて扁平化し、次いで、
最大径の方向にロールによる圧下を加えて丸鋳片を得る
方法が開示されている。しかし、凝固完了後であるため
扁平化によりセンターポロシティは閉塞されるが、完全
に圧着することが難しく、丸鋳片に戻す際にセンターポ
ロシティが再び開口するという問題がある。また、圧下
時の鋳片温度が低いため、鋳片中心部への圧下浸透度が
小さく圧下効率が低下し、センターポロシティの閉塞に
は大圧下が必要となり、それに伴い圧下負荷が増大して
設備が大型化するといった問題もある。[0006] Japanese Patent Application Laid-Open No. 9-201601 and
Japanese Patent Application Publication No. -201602 discloses a method of improving the center segregation and center porosity of Cr-containing steel by flattening a round slab after solidification is completed by applying rolling reduction with a roll,
A method of obtaining a round slab by applying a roll reduction in the direction of the maximum diameter is disclosed. However, since the solidification is completed, the center porosity is closed by the flattening, but it is difficult to completely press-bond, and there is a problem that the center porosity reopens when returning to the round slab. In addition, since the slab temperature at the time of rolling is low, the rolling penetration into the center of the slab is small and the rolling efficiency is reduced, and large pressure reduction is required to block the center porosity, and the rolling load increases with this. There is also a problem that the size becomes large.
【０００７】[0007]
【発明が解決しようとする課題】上述のように、従来技
術においては、中心偏析やセンターポロシティの改善が
不充分であり、また、真円度が悪化したり、さらに、割
れなどの鋳片の内質欠陥が発生し易いといった問題があ
る。更に、鋳込み開始時のように鋳造中に鋳込み速度が
変動すると、中心偏析やセンターポロシティなどの内質
や鋳片の真円度が悪化し易いことが判った。As described above, in the prior art, the center segregation and the improvement of the center porosity are insufficient, the roundness is deteriorated, and the cast slabs such as cracks are also deteriorated. There is a problem that an internal defect is likely to occur. Further, it has been found that if the casting speed fluctuates during casting, such as at the start of casting, the inner quality such as center segregation and center porosity and the roundness of the cast slab tend to deteriorate.
【０００８】本発明の目的は、特に、鋳込み速度の変動
に係わらず、中心偏析、センターポロシティおよび内部
割れなどの内部欠陥が少なく、かつ、真円度が良好な丸
鋳片の製造を可能とする連続鋳造丸鋳片の製造方法とそ
の製造装置を提供することにある。An object of the present invention is to make it possible to produce a round slab having a good roundness with few internal defects such as center segregation, center porosity and internal cracks irrespective of the fluctuation of the casting speed. It is an object of the present invention to provide a method for producing a continuous cast round slab and an apparatus for producing the same.
【０００９】[0009]
【課題を解決するための手段】本発明者は、連続鋳造に
よる丸鋳片の製造に関し、鋳造中の鋳片を圧下する技術
開発を推進し、種々の鋳造試験と検討をおこない、前記
課題に対し下記の技術が有効であることを確認した。Means for Solving the Problems The present inventor has promoted the development of technology for rolling down slabs during casting and has conducted various casting tests and examinations on the production of round slabs by continuous casting. On the other hand, the following technology was confirmed to be effective.
【００１０】(a) 凝固完了前の丸鋳片を未凝固圧下ロー
ルにて圧下して扁平化し、次いで、凝固完了後に前記扁
平化した丸鋳片を凝固後圧下ロールにて圧下して縮径し
た丸鋳片を製造する。(A) The round slab before solidification is reduced by an unsolidified reduction roll to flatten it, and after the solidification is completed, the flattened round slab is reduced by a reduction roll after solidification to reduce the diameter. To produce round cast slabs.
【００１１】(b) 鋳込み速度が変動するとき、変動する
鋳込み速度に応じて、未凝固圧下ロールおよび凝固後圧
下ロールの鋳込み方向における位置を変動させる。変動
する鋳込み速度が定常時の鋳込み速度より速いときは、
未凝固圧下ロールおよび凝固後圧下ロールの鋳込み方向
における位置を下流側に、遅いときは、上流側に移動す
る。(B) When the casting speed fluctuates, the positions of the unsolidified rolling roll and the solidified rolling roll in the casting direction are changed according to the fluctuating casting speed. When the variable casting speed is faster than the steady casting speed,
The positions in the casting direction of the unsolidified reduction roll and the post-solidification reduction roll move to the downstream side, and when slow, move to the upstream side.
【００１２】本発明は、上記知見に基づくもので、その
要旨は以下の(1) 〜(4) のとおりである。 (1) 連続鋳造され凝固完了前の丸鋳片に未凝固圧下ロー
ルにて圧下を加えて該丸鋳片を扁平化し、次いで、凝固
完了後に扁平化した前記鋳片に凝固後圧下ロールにて圧
下を加えて縮径した丸鋳片とする製造方法であって、鋳
込み速度が変動するとき、変動する該鋳込み速度に応じ
て、前記未凝固圧下ロールおよび凝固後圧下ロールの鋳
込み方向における位置を、それぞれ未凝固領域および凝
固領域に来るように変動させることを特徴とする連続鋳
造丸鋳片の製造方法。The present invention is based on the above findings, and the gist is as follows (1) to (4). (1) Continuously cast and flattened the round slab by applying unrolling to the round slab before solidification is completed with an unsolidified reduction roll, and then, after the solidification is completed, the flattened slab is solidified with a reduction roll. A method for producing a round cast slab having a reduced diameter by applying a reduction, and when a casting speed fluctuates, in accordance with the fluctuating casting speed, a position in a casting direction of the unsolidified reduction roll and the post-solidification reduction roll is determined. A method for producing a continuous cast round slab, wherein the method is varied so as to come to an unsolidified region and a solidified region, respectively.
【００１３】(2) 下記の式を満足するように未凝固圧下
ロールおよび凝固後圧下ロールの鋳込み方向における位
置を変動させることを特徴とする上記(1) 項に記載の連
続鋳造丸鋳片の製造方法。(2) The continuous cast round slab according to the above (1), wherein the positions in the casting direction of the unsolidified reduction roll and the post-solidification reduction roll are varied so as to satisfy the following expression. Production method.
【００１４】[0014]
【数２】 (Equation 2)
【００１５】ここで、α＝３．０〜０．３ ｄ(1) ：鋳込み速度変動時において、未凝固圧下ロール
の鋳込み方向における位置の、定常時での位置に対する
変動量（ｍ）（正値が定常時の位置から鋳込み方向の上
流側へ、負値が下流側への変動量） ｄ(2) ：鋳込み速度変動時において、凝固後圧下ロール
の鋳込み方向における位置の、定常時での位置に対する
変動量（ｍ）（正値が定常時の位置から鋳込み方向の上
流側へ、負値が下流側への変動量） Ｖ：定常時の鋳込み速度（ｍ／分） ｖ：変動時の鋳込み速度（ｍ／分） Ｄ(1) ：定常時でのモールドと未凝固圧下ロールとの間
の距離（ｍ） Ｄ(2) ：定常時でのモールドと凝固後圧下ロールとの間
の距離（ｍ） (3) 未凝固圧下ロールおよび凝固後圧下ロールを備えた
丸鋳片の連続鋳造装置において、前記未凝固圧下ロール
を取り付けたハウジングと、該ハウジングを積載する台
車と、該台車を鋳込み方向に位置調整自在に移動する駆
動機構とをさらに備えたことを特徴とする連続鋳造丸鋳
片の製造装置。Here, α = 3.0 to 0.3 d (1): the fluctuation amount (m) (positive) of the position in the casting direction of the unsolidified rolling roll with respect to the position in the steady state when the casting speed fluctuates. The value is the amount of fluctuation from the position in the steady state to the upstream side in the casting direction, and the negative value is the fluctuation amount to the downstream side. Fluctuation amount to position (m) (positive value is fluctuation amount from the position at the time of steady state to the upstream side in casting direction, negative value is fluctuation amount to the downstream side) V: Casting speed at steady state (m / min) v: Time of fluctuation Casting speed (m / min) D (1): distance between mold and unsolidified reduction roll at steady state (m) D (2): distance between mold and steady-state reduction roll at steady state (M) (3) In a continuous casting device for round slabs with unsolidified rolling rolls and solidified rolling rolls Manufacturing a continuous cast round slab, further comprising: a housing to which the unsolidified pressing roll is mounted; a trolley on which the housing is mounted; and a drive mechanism for moving the trolley so that the position can be adjusted in the pouring direction. apparatus.
【００１６】(4) 凝固後圧下ロールを取り付けたハウジ
ングと、該ハウジングを積載する台車と、該台車を鋳込
み方向に位置調整自在に移動する駆動機構とをさらに備
えたことを特徴とする上記(3) 項に記載の連続鋳造丸鋳
片の製造装置。(4) The above-mentioned (3), further comprising a housing to which a reduction roll is attached after solidification, a truck on which the housing is mounted, and a drive mechanism for moving the truck in a casting direction so as to be adjustable in position. Item 3) An apparatus for producing continuous cast round slabs according to item 3.
【００１７】なお、上記(1) において、「未凝固領域」
とは、丸鋳片の内部に固相率が０．８以下の未凝固層を
有する領域をいい、「凝固完了前」とは、該未凝固層を
有する状態をいう。「凝固領域」とは、前記未凝固層を
有しない領域をいい、「凝固完了後」とは、前記未凝固
層を有しない状態をいう。上記(2) において、「定常
時」とは、鋳込み速度が一定となり、ほぼ安定した鋳造
が実施されている状態をいう。In the above (1), the “unsolidified region”
Means a region having an unsolidified layer having a solid phase ratio of 0.8 or less in a round slab, and "before solidification is completed" means a state having the unsolidified layer. The “solidified region” refers to a region having no unsolidified layer, and the “after solidification” refers to a state having no unsolidified layer. In the above (2), “at a steady state” refers to a state in which the casting speed is constant and almost stable casting is being performed.
【００１８】[0018]
【発明の実施の形態】図１は、本発明の連続鋳造丸鋳片
の製造方法を説明する垂直曲げ型の連続鋳造装置の模式
図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of a vertical bending type continuous casting apparatus for explaining a method of manufacturing a continuously cast round cast piece of the present invention.
【００１９】図１に示すように、本発明の連続鋳造丸鋳
片の製造方法（以下、「本発明方法」ともいう）にあっ
ては、モールド１にて所定寸法に鋳造された丸鋳片２
は、ローラエプロン３およびピンチロール４を経て引き
抜かれ、内部に未凝固層５が存在する状態の凝固完了前
に未凝固圧下ロール６にて圧下が加えられて扁平化し、
次いで、前記扁平化した丸鋳片７は、凝固完了後に、前
記圧下方向に対して垂直の方向から、凝固後圧下ロール
８による圧下が加えられて縮径した丸鋳片９となり、ピ
ンチロール１０で引き抜かれる。この際、鋳込み速度が
変動したとき、変動する鋳込み速度に応じて、前記未凝
固圧下ロール６および凝固後圧下ロール８の鋳込み方向
における位置をそれぞれ未凝固領域および凝固領域に来
るように変動させる。なお、同図において、未凝固圧下
ロール６は水平式ロール、凝固後圧下ロール８は垂直式
ロールを例示したが、前者が垂直式で後者が水平式であ
ってもよい。As shown in FIG. 1, in the method for producing a continuous cast round slab of the present invention (hereinafter, also referred to as “the method of the present invention”), a round slab cast to a predetermined size in a mold 1 is used. 2
Is pulled out through the roller apron 3 and the pinch roll 4 and flattened by a non-solidification pressing roll 6 before flattening in a state where the non-solidified layer 5 is present therein,
Next, after the solidification of the round cast slab 7 is completed, after the solidification is completed, the round cast slab 9 is reduced in diameter by being reduced by a rolling roll 8 after solidification from a direction perpendicular to the rolling direction, and becomes a pinch roll 10. It is pulled out by. At this time, when the casting speed is changed, the positions of the unsolidified reduction roll 6 and the post-solidification reduction roll 8 in the casting direction are changed so as to come to the unsolidified region and the solidified region, respectively, according to the variable casting speed. Although the unsolidified pressing roll 6 is a horizontal roll and the post-solidifying pressing roll 8 is a vertical roll in the drawing, the former may be a vertical roll and the latter may be a horizontal roll.
【００２０】丸鋳片を扁平化する未凝固圧下ロール６と
しては、オーバル孔型やボックス孔型を有するロール、
あるいはフラット状のロールが用いられる。一方、扁平
化した丸鋳片に圧下を加える凝固後圧下ロール８として
は、ラウンド孔型を有するロールが用いられる。As the unsolidified rolling roll 6 for flattening the round slab, a roll having an oval hole type or a box hole type,
Alternatively, a flat roll is used. On the other hand, a roll having a round hole shape is used as the post-solidification reduction roll 8 for applying a reduction to the flattened round cast slab.
【００２１】未凝固圧下ロール６による丸鋳片の圧下量
は、圧下時点の未凝固層の厚さ以上とする。前記圧下量
が未凝固層の厚さ未満の場合には、凝固界面近傍に生じ
る引張応力により内部割れが発生し易い。未凝固層の厚
さ以上では、圧下の途中で一旦、凝固界面近傍に割れが
発生するものの凝固層が圧着された後は、凝固界面近傍
は圧縮応力の状態となり、割れが圧着され消滅する。上
記圧下量の最大限界および圧下時点の上記未凝固層の厚
さは、特に定めないが、前者は丸鋳片の厚さ（外径）の
４０％以下とするのが望ましく、後者は丸鋳片の厚さの
５％以上３０％以下が望ましい。なお、未凝固層の厚さ
とは、固相率が０．８以下の領域の厚さである。The amount of reduction of the round cast slab by the unsolidified reduction roll 6 should be equal to or greater than the thickness of the unsolidified layer at the time of reduction. If the rolling reduction is less than the thickness of the unsolidified layer, internal cracks are likely to occur due to tensile stress generated near the solidification interface. If the thickness of the unsolidified layer is greater than the thickness, cracks are once generated near the solidification interface during the rolling, but after the solidified layer is pressed, the vicinity of the solidification interface is in a state of compressive stress, and the cracks are pressed and disappear. The maximum limit of the reduction amount and the thickness of the unsolidified layer at the time of the reduction are not particularly defined, but the former is desirably 40% or less of the thickness (outer diameter) of the round cast piece, and the latter is the round cast. It is desirable that the thickness be 5% or more and 30% or less of the thickness of the piece. In addition, the thickness of the unsolidified layer is a thickness of a region where the solid fraction is 0.8 or less.
【００２２】丸鋳片の内部に存在するセンターポロシテ
ィは、未凝固圧下ロール６による凝固完了前の圧下によ
り圧着し、それにともない、濃化溶鋼の集積が抑制され
るため中心偏析も改善される。The center porosity existing inside the round cast slab is pressed by reduction before the solidification is completed by the unsolidified reduction roll 6, and the accumulation of the concentrated molten steel is suppressed, so that the center segregation is also improved.
【００２３】上記圧下により扁平化した丸鋳片は、凝固
後圧下ロール８による凝固完了後の圧下により断面形状
が修正されて、真円度の高い縮径した丸鋳片が得られ
る。The cross section of the round slab that has been flattened by the reduction is corrected by the reduction after the solidification by the reduction roll 8 after solidification, and a round slab having a reduced diameter and a high roundness is obtained.
【００２４】本発明方法にあっては、鋳込み速度が変動
するとき、変動する該鋳込み速度に応じて、未凝固圧下
ロールおよび凝固後圧下ロールの鋳込み方向における位
置をそれぞれ未凝固領域および凝固領域に来るように移
動させる。すなわち、変動時の鋳込み速度が定常時の鋳
込み速度より速いときには、未凝固圧下ロールおよび凝
固後圧下ロールを鋳込み方向の下流側に、また、遅いと
きは、鋳込み方向の上流側に、その位置を調整すること
により、未凝固圧下ロール６ならびに凝固後圧下ロール
８での圧下の際の丸鋳片断面内部の温度分布あるいは未
凝固層厚さの鋳込み方向変動を抑制することができ、中
心偏析やセンターポロシティなどの内質欠陥の抑制およ
び鋳片の真円度の改善を鋳込み方向に安定させることが
可能となる。In the method of the present invention, when the pouring speed fluctuates, the positions of the unsolidified rolling roll and the post-solidified rolling roll in the pouring direction are respectively set to the unsolidified region and the solidified region in accordance with the fluctuating pouring speed. Move to come. That is, when the casting speed at the time of fluctuation is higher than the casting speed at the steady state, the unsolidified reduction roll and the post-solidification reduction roll are positioned downstream in the casting direction, and when low, the positions are positioned upstream in the casting direction. By adjusting, it is possible to suppress the temperature distribution in the round cast slab cross section or the fluctuation of the thickness of the unsolidified layer in the casting direction during the reduction by the unsolidified reduction roll 6 and the post-solidification reduction roll 8, and to suppress center segregation and It is possible to suppress the internal defects such as center porosity and to improve the roundness of the slab in the casting direction.
【００２５】本発明の好適態様にあっては、下記の式を
満足するように未凝固圧下ロールおよび凝固後圧下ロー
ルの鋳込み方向における位置を変動させることを特徴と
する。A preferred embodiment of the present invention is characterized in that the positions in the casting direction of the unsolidified reduction roll and the post-solidification reduction roll are varied so as to satisfy the following expression.
【００２６】[0026]
【数３】 (Equation 3)
【００２７】ここで、α＝３．０〜０．３ ｄ(1) ：鋳込み速度変動時において、未凝固圧下ロール
の鋳込み方向における位置の、定常時での位置に対する
変動量（ｍ）（正値が定常時の位置から鋳込み方向の上
流側へ、負値が下流側への変動量） ｄ(2) ：鋳込み速度変動時において、凝固後圧下ロール
の鋳込み方向における位置の、定常時での位置に対する
変動量（ｍ）（正値が定常時の位置から鋳込み方向の上
流側へ、負値が下流側への変動量） Ｖ：定常時の鋳込み速度（ｍ／分） ｖ：変動時の鋳込み速度（ｍ／分） Ｄ(1) ：定常時でのモールドと未凝固圧下ロールとの間
の距離（ｍ） Ｄ(2) ：定常時でのモールドと凝固後圧下ロールとの間
の距離（ｍ） 上記αが３．０以下０．３以上の範囲で未凝固圧下ロー
ルおよび凝固後圧下ロールの鋳込みにおける位置を変動
させることにより、鋳込み速度が変動したときでも、圧
下時の丸鋳片断面内部の温度分布あるいは未凝固層厚さ
の鋳込み方向変動が効果的に抑制されるため、内部欠陥
の発生が抑制され高い真円度を有する長手方向に均一な
安定した品質の丸鋳片が得られる。αが０．３未満、あ
るいは３．０を越えると、鋳込み速度が変動したとき、
中心偏析やセンターポロシティなどの内質や真円度が悪
化する。Here, α = 3.0 to 0.3 d (1): the amount of change (m) (positive) of the position of the unsolidified rolling roll in the casting direction relative to the position in the steady state when the casting speed is changed. The value is the amount of fluctuation from the position at the steady state to the upstream side in the casting direction, and the negative value is the fluctuation amount to the downstream side. Fluctuation amount to position (m) (positive value is fluctuation amount from the position at the time of steady state to the upstream side in casting direction, negative value is fluctuation amount to the downstream side) V: Casting speed at steady state (m / min) v: Time of fluctuation Pouring speed (m / min) D (1): distance between mold and unsolidified pressing roll in steady state (m) D (2): distance between mold and fixed solidifying pressing roll in steady state (M) Casting of an unsolidified reduction roll and a post-solidification reduction roll when α is 3.0 or less and 0.3 or more. By changing the position in the casting, even when the casting speed fluctuates, fluctuations in the casting direction of the temperature distribution or unsolidified layer thickness inside the round cast slab during rolling are effectively suppressed, and internal defects The generation of round cast slabs with stable quality and uniformity in the longitudinal direction having suppressed roundness and high roundness is obtained. If α is less than 0.3 or exceeds 3.0, when the casting speed fluctuates,
Inner quality such as center segregation and center porosity and roundness deteriorate.
【００２８】図２は、本発明に係る未凝固圧下ロールあ
るいは凝固後圧下ロールを積載した台車およびその駆動
装置を模式的に示す側面図で、水平ロールを搭載した例
である。FIG. 2 is a side view schematically showing a carriage loaded with an unsolidified reduction roll or a reduction roll after solidification according to the present invention and a driving device thereof, in which a horizontal roll is mounted.
【００２９】本発明の連続鋳造装置は、図示例では、一
対の水平ロール２１を上下に取り付けたハウジング２２
と、該ハウジング２２を積載し車輪２３を有する台車２
４と、レール２５上の該台車２４を鋳込み方向に位置調
整自在に移動する駆動機構２６を備えている。駆動機構
２６は、駆動装置２７と駆動回転軸２８とから構成され
ており、駆動装置２７のアクチュエータとしては、油圧
モータや電気モータなどを用いることができる。なお、
垂直ロールを搭載する場合には、ハウジングは、一対の
垂直ロールを鋳込み方向の左右に取り付けた構造とな
り、それ以外の構造は図２と同様である。また、台車を
鋳込み方向に移動させるためのかかる構造は、台車を鋳
込み方向に移動することができれば、その他の構造であ
ってもよい。In the illustrated example, the continuous casting apparatus according to the present invention comprises a housing 22 having a pair of horizontal rolls 21 mounted vertically.
And a bogie 2 carrying the housing 22 and having wheels 23
4 and a drive mechanism 26 that moves the carriage 24 on the rail 25 in the casting direction so as to be freely adjustable. The drive mechanism 26 includes a drive device 27 and a drive rotation shaft 28, and a hydraulic motor, an electric motor, or the like can be used as an actuator of the drive device 27. In addition,
When mounting a vertical roll, the housing has a structure in which a pair of vertical rolls are attached to the left and right in the casting direction, and the other structure is the same as that of FIG. Further, such a structure for moving the cart in the casting direction may be another structure as long as the cart can be moved in the casting direction.
【００３０】なお、未凝固圧下ロールおよび凝固後圧下
ロールの鋳込み方向における位置の調整は、鋳込み速度
の変動開始とほぼ同時に未凝固圧下ロールおよび凝固後
圧下ロールの移動を開始し、その移動速度は、鋳込み速
度の変動分に対応して０．１〜０．８ｍ／分程度とする
のが望ましい。Adjustment of the position of the unsolidified reduction roll and the post-solidification reduction roll in the casting direction starts the movement of the unsolidified reduction roll and the post-solidification reduction roll almost simultaneously with the start of the fluctuation of the casting speed. It is desirable to set it to about 0.1 to 0.8 m / min corresponding to the variation of the casting speed.
【００３１】[0031]
【実施例】（実施例１）図２に示す基本構造の台車、す
なわち、凝固完了前に圧下をおこなう水平式の未凝固圧
下ロールを積載した台車と凝固完了後に圧下をおこなう
垂直式の凝固後圧下ロールを積載した台車を製作し、図
１に示すように垂直曲げ型の連続鋳造装置に組み込ん
だ。表１に連続鋳造装置の主仕様を示す。(Embodiment 1) A bogie having the basic structure shown in FIG. 2, that is, a bogie loaded with a horizontal unsolidified rolling roll that performs rolling before solidification is completed, and a vertical solidification that performs rolling after solidification is completed A trolley loaded with a reduction roll was manufactured, and was incorporated in a vertical bending type continuous casting apparatus as shown in FIG. Table 1 shows the main specifications of the continuous casting apparatus.
【００３２】[0032]
【表１】 [Table 1]
【００３３】未凝固圧下ロールと凝固後圧下ロールは、
定常時として、それぞれ、モールドより２７ｍと３２ｍ
の下流の位置に配置し、両者ともレール上を鋳造方向に
±１０ｍの距離の移動が可能な構造とした。The unsolidified reduction roll and the post-solidification reduction roll are:
As usual, 27m and 32m respectively from the mold
, Both of which are configured to be movable on the rail by a distance of ± 10 m in the casting direction.
【００３４】未凝固圧下ロールおよび凝固後圧下ロール
は、ロール径がともに６００ｍｍで、未凝固圧下ロール
は溝底径が５２０ｍｍのオーバル孔型を有する水平ロー
ルで、凝固後圧下ロールは曲率半径が９５ｍｍのラウン
ド孔型を有する垂直ロールとした。The unsolidified reduction roll and the post-solidification reduction roll each have a roll diameter of 600 mm. The unsolidified reduction roll is a horizontal roll having an oval hole shape with a groove bottom diameter of 520 mm. The post-solidification reduction roll has a radius of curvature of 95 mm. Vertical roll having a round hole shape.
【００３５】（実施例２）表１に示した垂直曲げ型の連
続鋳造装置を用い、外径２２５ｍｍの１３％Ｃｒ鋼の丸
鋳片を鋳造し、未凝固圧下ロールと、それに続く凝固後
圧下ロールで所定の圧下を加え、外径１９１ｍｍの丸鋳
片を製造した。なお、定常時の鋳込み速度は、２．０ｍ
／分で、この時、凝固完了位置はモールドから３２ｍ下
流となる。(Example 2) Using a vertical bending type continuous casting apparatus shown in Table 1, a 13% Cr steel round cast piece having an outer diameter of 225 mm was cast, and a non-solidifying reduction roll and a subsequent reduction after solidification were performed. A predetermined reduction was applied by a roll to produce a round cast piece having an outer diameter of 191 mm. In addition, the pouring speed in the steady state is 2.0 m
/ Min at this time, the solidification completion position is 32 m downstream from the mold.
【００３６】鋳込み速度は、鋳造中に１．７〜２．０ｍ
／分の範囲で変動し、この速度に対応して、未凝固圧下
ロールおよび凝固後圧下ロールの鋳込み方向における位
置を変動させた。すなわち、鋳込み開始時の鋳込み速度
は、１．７ｍ／分で、その凝固完了位置はメニスカスか
ら２７ｍ下流の地点となるため、未凝固圧下ロールおよ
び凝固後圧下ロールを鋳込み方向の上流側へ移動させて
圧下を開始し、その後の鋳込み速度の増加に伴い未凝固
圧下ロールおよび凝固後圧下ロールを鋳込み方向の下流
側へ移動させて圧下をおこなった。 表２に製造条件を
示す。The casting speed is 1.7 to 2.0 m during casting.
/ Min, and the positions in the casting direction of the unsolidified reduction roll and the post-solidification reduction roll were varied corresponding to this speed. That is, since the casting speed at the start of casting is 1.7 m / min and the solidification completion position is a point 27 m downstream from the meniscus, the unsolidified reduction roll and the post-solidification reduction roll are moved to the upstream side in the casting direction. Then, the unsolidified reduction roll and the post-solidification reduction roll were moved to the downstream side in the casting direction to perform the reduction with an increase in the casting speed thereafter. Table 2 shows the manufacturing conditions.
【００３７】[0037]
【表２】 [Table 2]
【００３８】本発明例１、２、３、４は、未凝固圧下ロ
ールおよび凝固後圧下ロールの変動量を決める前記αの
値を、それぞれ、０．５２、１．０４、１．５６、２．
０８とした。In Examples 1, 2, 3, and 4 of the present invention, the values of α that determine the amount of fluctuation of the unsolidified rolling roll and the post-solidifying rolling roll were 0.52, 1.04, 1.56, and 1.56, respectively. .
08.
【００３９】図３は、鋳込み速度と未凝固圧下ロールの
鋳込み方向における位置との関係を示すグラフである。
図４は、鋳込み速度と凝固後圧下ロールの鋳込み方向に
おける位置との関係を示すグラフである。FIG. 3 is a graph showing the relationship between the casting speed and the position of the unsolidified pressing roll in the casting direction.
FIG. 4 is a graph showing the relationship between the casting speed and the position of the post-solidification reduction roll in the casting direction.
【００４０】図３および図４に示すように、本発明例
１、２、３、４は、鋳込み開始時、未凝固圧下ロールを
モールドから鋳込み方向の上流側にそれぞれ２４．９
ｍ、２２．８ｍ、２０．７ｍ、１８．６ｍの位置に移動
し、また、凝固後圧下ロールをモールドから鋳込み方向
の上流側にそれぞれ２９．５ｍ、２７．０ｍ、２４．５
ｍ、２２．０ｍの位置に移動して圧下を開始し、鋳込み
速度の増加に伴い、前記α値に基づき前記定常時での位
置まで下流側に移動した。なお、比較例１は、未凝固圧
下ロールおよび凝固後圧下ロールを前記定常時の位置に
固定した場合である。As shown in FIGS. 3 and 4, in Examples 1, 2, 3, and 4 of the present invention, at the start of casting, the unsolidified pressing rolls were each placed 24.9 upstream of the mold in the casting direction.
m, 22.8 m, 20.7 m, 18.6 m, and after the solidification, the reduction roll was moved 29.5 m, 27.0 m, 24.5 m upstream from the mold in the casting direction.
m, and moved to the position of 22.0 m to start the reduction, and with the increase in the casting speed, moved downstream to the position at the steady state based on the α value. Comparative Example 1 is a case where the unsolidified pressing roll and the post-solidifying pressing roll were fixed at the above-mentioned stationary positions.
【００４１】上記方法により得られた丸鋳片の真円度を
調査した。鋳込み速度毎に鋳片の横断面サンプルを採取
し、凝固後圧下ロールの圧下方向軸を基準として円周方
向に１０゜ピッチで直径を測定し、その断面内の外径差
（最大外径−最小外径）と平均外径との比を真円度
（％）と定義し、真円度を評価した。The roundness of the round slab obtained by the above method was examined. A cross section sample of the slab is taken at each casting speed, and after solidification, the diameter is measured at a pitch of 10 ° in the circumferential direction with respect to the rolling direction axis of the rolling roll, and the outer diameter difference (maximum outer diameter− The ratio between the minimum outer diameter) and the average outer diameter was defined as roundness (%), and the roundness was evaluated.
【００４２】図５は、鋳込み速度と丸鋳片の真円度との
関係を示すグラフである。同図に示すように、本発明例
１〜４は、いずれも比較例に比べ真円度が改善されてお
り、変動する鋳込み速度に応じて未凝固圧下ロールおよ
び凝固後圧下ロールの鋳込み方向における位置を移動さ
せることにより丸鋳片の真円度が向上することが確認さ
れた。特に、本発明例３と４は、鋳込み開始時の鋳込み
速度が遅い条件下においても、マンネスマン穿孔用素材
として要求される真円度の確保がほぼ可能となり、不良
品の減少による大幅な歩留まり向上ができた。FIG. 5 is a graph showing the relationship between the casting speed and the roundness of the round slab. As shown in the figure, each of Examples 1 to 4 of the present invention has improved roundness as compared with the comparative example, and in the casting direction of the unsolidified reduction roll and the post-solidification reduction roll in accordance with the variable casting speed. It was confirmed that the roundness of the round slab was improved by moving the position. In particular, in Examples 3 and 4 of the present invention, even under the condition where the casting speed at the start of casting is low, the roundness required as a material for Mannesmann drilling can be almost ensured, and the yield is greatly improved due to the reduction of defective products. Was completed.
【００４３】表３は、鋳込み速度と中心偏析、センター
ポロシティおよび内部割れとの関係を整理した結果であ
り、鋳込み速度毎に鋳片の横断面サンプルを採取して評
価した。Table 3 shows the relationship between the casting speed and the relationship between the center segregation, the center porosity and the internal cracks. A cross section sample of the slab was taken for each casting speed and evaluated.
【００４４】[0044]
【表３】 [Table 3]
【００４５】表３に示すように、本発明例は、いずれも
比較例に比べ内部欠陥の発生が抑制されており、特に、
本発明例３と４は、鋳込み開始時の鋳込み速度が遅い条
件下においても、マンネスマン穿孔用素材として要求さ
れる内質の確保がほぼ可能となった。As shown in Table 3, in each of the examples of the present invention, the occurrence of internal defects was suppressed as compared with the comparative example.
In Examples 3 and 4 of the present invention, even under the condition where the casting speed at the start of casting was low, it was almost possible to secure the contents required as a material for Mannesmann drilling.
【００４６】[0046]
【発明の効果】本発明により、鋳込み速度の変動に係わ
らず、中心偏析やセンターポロシティなどの内質欠陥が
少なく、かつ、真円度の高い連続鋳造丸鋳片を製造する
ことが可能となった。According to the present invention, it is possible to produce continuous cast round slabs having a small degree of internal defects such as center segregation and center porosity and having a high roundness, irrespective of the fluctuation of the casting speed. Was.
【図１】本発明の連続鋳造丸鋳片の製造方法を説明する
垂直曲げ型の連続鋳造装置の模式図である。FIG. 1 is a schematic view of a vertical bending type continuous casting apparatus for explaining a method for producing a continuous cast round slab of the present invention.
【図２】本発明に係る未凝固圧下ロールあるいは凝固後
圧下ロールを積載した台車およびその駆動装置を模式的
に示す側面図で、水平ロールを搭載した例である。FIG. 2 is a side view schematically showing a carriage loaded with an unsolidified rolling roll or a roll after solidification according to the present invention and a driving device thereof, in which a horizontal roll is mounted.
【図３】鋳込み速度と未凝固圧下ロールの鋳込み方向に
おける位置との関係を示すグラフである。FIG. 3 is a graph showing a relationship between a casting speed and a position of an unsolidified pressing roll in a casting direction.
【図４】鋳込み速度と凝固後圧下ロールの鋳込み方向に
おける位置との関係を示すグラフである。FIG. 4 is a graph showing a relationship between a casting speed and a position of a reduction roll after solidification in a casting direction.
【図５】鋳込み速度と丸鋳片の真円度との関係を示すグ
ラフである。FIG. 5 is a graph showing the relationship between the casting speed and the roundness of a round slab.
１ モールド ２、７、９ 丸鋳片 ３ ローラエプロン ４、１０ ピンチロール ５ 未凝固層 ６ 未凝固圧下ロール ８ 凝固後圧下ロール ２１ 水平ロール ２２ ハウジング ２３ 車輪 ２４ 台車 ２５ レール ２６ 駆動機構 ２７ 駆動装置 ２８ 駆動回転軸 DESCRIPTION OF SYMBOLS 1 Mold 2, 7, 9 Round cast piece 3 Roller apron 4, 10 Pinch roll 5 Non-solidified layer 6 Non-solidified reduction roll 8 Post-solidification reduction roll 21 Horizontal roll 22 Housing 23 Wheel 24 Carriage 25 Rail 26 Drive mechanism 27 Drive 28 Drive rotation axis
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｂ２２Ｄ 11/12 Ｂ２２Ｄ 11/12 Ａ 11/20 11/20 Ｃ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI B22D 11/12 B22D 11/12 A 11/20 11/20 C
Claims (4)
固圧下ロールにて圧下を加えて該丸鋳片を扁平化し、次
いで、凝固完了後に扁平化した前記鋳片に凝固後圧下ロ
ールにて圧下を加えて縮径した丸鋳片とする製造方法で
あって、鋳込み速度が変動するとき、変動する該鋳込み
速度に応じて、前記未凝固圧下ロールおよび凝固後圧下
ロールの鋳込み方向における位置を、それぞれ未凝固領
域および凝固領域に来るように変動させることを特徴と
する連続鋳造丸鋳片の製造方法。An unsolidified rolling roll is applied to a continuously cast and yet solidified round slab to reduce the round slab, and then the flattened slab is rolled after the solidification is completed. A method for producing a round slab reduced in diameter by applying a reduction in the casting speed, when the casting speed fluctuates, according to the fluctuating casting speed, in the casting direction of the unsolidified reduction roll and the post-solidification reduction roll. A method for producing a continuously cast round slab, wherein the position is changed so as to come to an unsolidified region and a solidified region, respectively.
ールおよび凝固後圧下ロールの鋳込み方向における位置
を変動させることを特徴とする請求項１に記載の連続鋳
造丸鋳片の製造方法。 【数１】 ここで、α＝３．０〜０．３ ｄ(1) ：鋳込み速度変動時において、未凝固圧下ロール
の鋳込み方向における位置の、定常時での位置に対する
変動量（ｍ）（正値が定常時の位置から鋳込み方向の上
流側へ、負値が下流側への変動量） ｄ(2) ：鋳込み速度変動時において、凝固後圧下ロール
の鋳込み方向における位置の、定常時での位置に対する
変動量（ｍ）（正値が定常時の位置から鋳込み方向の上
流側へ、負値が下流側への変動量） Ｖ：定常時の鋳込み速度（ｍ／分） ｖ：変動時の鋳込み速度（ｍ／分） Ｄ(1) ：定常時でのモールドと未凝固圧下ロールとの間
の距離（ｍ） Ｄ(2) ：定常時でのモールドと凝固後圧下ロールとの間
の距離（ｍ）2. The method according to claim 1, wherein the positions of the unsolidified reduction roll and the post-solidification reduction roll in the casting direction are varied so as to satisfy the following expression. (Equation 1) Here, α = 3.0 to 0.3 d (1): the fluctuation amount (m) of the position in the casting direction of the unsolidified reduction roll with respect to the position in the steady state when the casting speed fluctuates (the positive value is constant). D (2): Variation of the position in the casting direction of the post-solidification reduction roll with respect to the position in the steady state when the casting speed fluctuates, from the normal position to the upstream side in the casting direction and the negative value to the downstream side. Amount (m) (Positive value is the amount of fluctuation from the position at the steady state to the upstream side in the casting direction, and negative value is the fluctuation amount to the downstream side) V: Casting speed at the steady state (m / min) v: Casting speed at the time of fluctuation ( m / min) D (1): distance between the mold and the unsolidified rolling roll at steady state (m) D (2): distance between the mold and the solidified rolling roll after steady state (m)
ルを備えた丸鋳片の連続鋳造装置において、前記未凝固
圧下ロールを取り付けたハウジングと、該ハウジングを
積載する台車と、該台車を鋳込み方向に位置調整自在に
移動する駆動機構とをさらに備えたことを特徴とする連
続鋳造丸鋳片の製造装置。3. A continuous casting apparatus for a round cast piece provided with an unsolidified reduction roll and a post-solidification reduction roll, a housing to which the unsolidified reduction roll is mounted, a bogie on which the housing is mounted, and a direction in which the bogie is cast. And a drive mechanism for adjusting the position of the continuous cast slab.
グと、該ハウジングを積載する台車と、該台車を鋳込み
方向に位置調整自在に移動する駆動機構とをさらに備え
たことを特徴とする請求項３に記載の連続鋳造丸鋳片の
製造装置。4. The apparatus according to claim 3, further comprising: a housing to which a reduction roll is attached after solidification, a truck on which the housing is mounted, and a drive mechanism for moving the truck in a casting direction so as to be adjustable in position. 3. The continuous cast round slab production apparatus according to item 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11361898A JPH11309552A (en) | 1998-04-23 | 1998-04-23 | Production of continuously cast round billet and producing apparatus thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11361898A JPH11309552A (en) | 1998-04-23 | 1998-04-23 | Production of continuously cast round billet and producing apparatus thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11309552A true JPH11309552A (en) | 1999-11-09 |
Family
ID=14616787
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11361898A Withdrawn JPH11309552A (en) | 1998-04-23 | 1998-04-23 | Production of continuously cast round billet and producing apparatus thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11309552A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1291099A2 (en) * | 2001-09-08 | 2003-03-12 | SMS Demag AG | Verfahren und Vorrichtung zur Optimierung der Qualität von Gussträngen mit runden oder annähernd runden Querschnitten |
| KR100882104B1 (en) * | 2001-12-24 | 2009-02-06 | 반 도르네스 트랜스미씨 비.브이. | Work piece, metal push belt and method and processing tool for producing the same |
| CN102179407A (en) * | 2011-03-17 | 2011-09-14 | 宁波钢铁有限公司 | Method for preparing hot rolling strip steel capable of preventing edge crack of extremely thin rolled strip steel |
| JP2016022531A (en) * | 2014-07-24 | 2016-02-08 | 新日鐵住金株式会社 | Continuous casting method of cast slab and cast slab |
-
1998
- 1998-04-23 JP JP11361898A patent/JPH11309552A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1291099A2 (en) * | 2001-09-08 | 2003-03-12 | SMS Demag AG | Verfahren und Vorrichtung zur Optimierung der Qualität von Gussträngen mit runden oder annähernd runden Querschnitten |
| EP1291099A3 (en) * | 2001-09-08 | 2003-12-10 | SMS Demag AG | Method and device for optimizing the quality of continuously cast ingots, having a circular or quasi circular cross-section |
| KR100882104B1 (en) * | 2001-12-24 | 2009-02-06 | 반 도르네스 트랜스미씨 비.브이. | Work piece, metal push belt and method and processing tool for producing the same |
| CN102179407A (en) * | 2011-03-17 | 2011-09-14 | 宁波钢铁有限公司 | Method for preparing hot rolling strip steel capable of preventing edge crack of extremely thin rolled strip steel |
| JP2016022531A (en) * | 2014-07-24 | 2016-02-08 | 新日鐵住金株式会社 | Continuous casting method of cast slab and cast slab |
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| A300 | Withdrawal of application because of no request for examination |
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