JP5556421B2 - Manufacturing method of high cleanliness steel slab by continuous casting - Google Patents

Manufacturing method of high cleanliness steel slab by continuous casting Download PDF

Info

Publication number
JP5556421B2
JP5556421B2 JP2010142299A JP2010142299A JP5556421B2 JP 5556421 B2 JP5556421 B2 JP 5556421B2 JP 2010142299 A JP2010142299 A JP 2010142299A JP 2010142299 A JP2010142299 A JP 2010142299A JP 5556421 B2 JP5556421 B2 JP 5556421B2
Authority
JP
Japan
Prior art keywords
molten steel
weir
tundish
injection site
steel injection
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.)
Active
Application number
JP2010142299A
Other languages
Japanese (ja)
Other versions
JP2012006025A (en
Inventor
孝平 古米
祐司 三木
剛 村井
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
Original Assignee
JFE Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by JFE Steel Corp filed Critical JFE Steel Corp
Priority to JP2010142299A priority Critical patent/JP5556421B2/en
Publication of JP2012006025A publication Critical patent/JP2012006025A/en
Application granted granted Critical
Publication of JP5556421B2 publication Critical patent/JP5556421B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Continuous Casting (AREA)

Description

本発明は、連続鋳造による高清浄度鋼鋳片の製造方法に関し、詳しくは、タンディッシュにおいて、脱酸生成物などの酸化物系非金属介在物の浮上分離を促進させて溶鋼の清浄性を高める方法に関する。   The present invention relates to a method for producing a high cleanliness steel slab by continuous casting. More specifically, the tundish promotes the floating separation of oxide-based non-metallic inclusions such as deoxidation products to improve the cleanliness of molten steel. It relates to how to increase.

鋼の連続鋳造では、取鍋内の溶鋼を一旦タンディッシュに注入し、タンディッシュ内に所定量の溶鋼を滞留させた状態で、タンディッシュから鋳型内に溶鋼を注入して鋳片を製造している。タンディッシュは、複数ヒートの連続鋳造を継続する際の取鍋交換時の溶鋼の供給機能、及び、複数の鋳型への溶鋼の分配機能を有するのみならず、タンディッシュ内に所定量の溶鋼を滞留させることで、タンディッシュから鋳型への溶鋼流出量が精度良く制御される、更には、溶鋼中に懸濁する脱酸生成物などの酸化物系非金属介在物（以下、単に「介在物」と記す）の浮上分離が促進されるなどの機能を有している。特に、近年の高品質の鉄鋼材料の要求から、タンディッシュにおいて介在物を効率的に浮上分離する技術が広く行われている。   In continuous casting of steel, the molten steel in the ladle is once poured into the tundish, and with a predetermined amount of molten steel retained in the tundish, the molten steel is poured into the mold from the tundish to produce a slab. ing. The tundish not only has the function of supplying molten steel at the time of ladle replacement when continuing continuous casting of multiple heats and the function of distributing molten steel to multiple molds, but also provides a predetermined amount of molten steel in the tundish. The amount of molten steel flowing out of the tundish from the mold to the mold is accurately controlled by the retention, and further, oxide-based nonmetallic inclusions such as deoxidation products suspended in the molten steel (hereinafter simply referred to as “inclusions”). )), And the like. In particular, due to the recent demand for high-quality steel materials, a technique for efficiently levitating and separating inclusions in tundish is widely used.

タンディッシュにおける介在物の浮上分離方法は、タンディッシュ内に堰を設置し、堰によって溶鋼の流動を制御する方法が一般的である。例えば、特許文献１には、下部に貫通孔を有し、タンディッシュの底部からタンディッシュ内の溶鋼湯面上にまで伸びる堰を、取鍋からの溶鋼の注入部位を挟んでタンディッシュ内の２箇所に相対して配置し、タンディッシュ内を受鋼領域と鋼準静止領域とに分離し、鋼準静止領域での介在物の浮上分離を目的とするタンディッシュが開示されている。   As a method for floating and separating inclusions in a tundish, a method is generally used in which a weir is installed in the tundish and the flow of molten steel is controlled by the weir. For example, in Patent Document 1, a weir that has a through hole in the lower part and extends from the bottom of the tundish to the surface of the molten steel in the tundish is placed inside the tundish with the molten steel injection site from the ladle interposed therebetween. There is disclosed a tundish that is disposed so as to be opposed to two places, and the inside of the tundish is separated into a steel receiving region and a steel quasi-static region, and the inclusions are separated and floated in the steel quasi-static region.

特許文献２には、タンディッシュの底部に接する２個の貫通孔を有する堰によりタンディッシュ内を受鋼側と出鋼側とに分離し、且つ、前記堰の下流側にダム状の堰（下堰という）を配置し、更に、タンディッシュの長辺長さＬと短辺長さＷとの比Ｌ／Ｗを２〜７、受鋼側の容積比率を全体の１０〜４０％とするタンディッシュが開示されている。   In Patent Document 2, the inside of the tundish is separated into the receiving steel side and the outgoing steel side by a weir having two through holes in contact with the bottom of the tundish, and a dam-like weir ( And the ratio L / W between the long side length L and the short side length W of the tundish is 2 to 7, and the volume ratio on the steel receiving side is 10 to 40% of the whole. A tundish is disclosed.

また、特許文献３には、耐熱性組成物から形成されるタンディッシュ衝突パッドであって、該パッドが衝突面を備えたベースと、該ベースから上方に伸び且つ前記溶融金属の流れを受け入れるための上側開口部を備えた内部空間を完全に囲む無端の外側側壁部とを有し、前記外側側壁部が前記開口部へ向けて内方に且つ上方に伸びる少なくとも第１部分を備えた環状の内面を含むタンディッシュ衝突パッドが開示されている。   Patent Document 3 discloses a tundish collision pad formed from a heat-resistant composition, the pad having a collision surface, and extending upward from the base and receiving the flow of the molten metal. An endless outer side wall that completely surrounds the internal space with the upper opening, and the outer side wall has an annular shape with at least a first portion extending inward and upward toward the opening A tundish impact pad including an inner surface is disclosed.

特許文献３の技術を改善する技術も提案されており、特許文献４には、取鍋から注入される溶融金属流がタンディッシュ底部に衝突する部分に設置される、タンディッシュ内溶融金属の流動制御パッドであって、溶融金属流の衝突部を囲んでタンディッシュの底部から上方へ伸びる壁部と、該壁部の上端部位から壁部の囲み中心へ向かって伸びる庇状部とを有し、タンディッシュの長辺内壁と対向する側の壁部に、切り欠きを有する流動制御パッドが開示されている。   A technique for improving the technique of Patent Document 3 has also been proposed. Patent Document 4 describes the flow of molten metal in a tundish that is installed in a portion where a molten metal flow injected from a ladle collides with the bottom of the tundish. A control pad having a wall portion extending upward from the bottom of the tundish surrounding the collision portion of the molten metal flow, and a hook-shaped portion extending from the upper end portion of the wall portion toward the surrounding wall center. The flow control pad which has a notch in the wall part on the side facing the long side inner wall of the tundish is disclosed.

また、特許文献５には、特許文献３の衝突パッドは一体構造の耐火物であることから、衝突パッドに代えて堰とするべく、取鍋からタンディッシュへの溶融金属流に相対してタンディッシュの底部から上方へ伸びる壁部と、該壁部の上端部位から溶融金属流へ向かって伸びる庇状部と、を有する流動制御用堰であって、前記壁部の高さｈ及び庇状部の幅ｄが、０．１≦ｄ／ｈ≦１．０なる関係式を満足する堰が開示されている。   Further, in Patent Document 5, since the collision pad of Patent Document 3 is a refractory having an integral structure, a tank is formed relative to the molten metal flow from the ladle to the tundish so as to be a weir instead of the collision pad. A flow control weir having a wall portion extending upward from the bottom of the dish and a hook-like portion extending from the upper end portion of the wall portion toward the molten metal flow, wherein the wall portion has a height h and a hook-like shape. A weir is disclosed in which the width d of the portion satisfies the relational expression of 0.1 ≦ d / h ≦ 1.0.

更に、特許文献６には、取鍋からタンディッシュへの溶鋼流がタンディッシュ底部に衝突する部分に、該溶鋼流の衝突部を囲んでタンディッシュの底部から上方へ伸びる壁部と、該壁部の上端部位から壁部の囲み中心へ向かって伸びる庇状部とを有する流動制御パッドの配置されたタンディッシュを用い、溶鋼注入速度Ｑ（ｍ3／ｍｉｎ）、庇部を除いた流動制御パッド上面の面積Ｓ１（ｍ2）及び流動制御パッド底面の面積Ｓ２（ｍ2）が、０．５＜（Ｑ／Ｓ２）×（Ｓ１／Ｓ２）＜５．０なる関係式を満足する条件で連続鋳造する高清浄鋼鋳片の製造方法が開示されている。 Further, Patent Document 6 discloses that a portion of the molten steel flow from the ladle to the tundish collides with the bottom of the tundish, a wall portion surrounding the collision portion of the molten steel flow and extending upward from the bottom of the tundish; Control using a tundish in which a flow control pad having a hook-shaped portion extending from the upper end portion of the wall portion toward the enclosing center of the wall portion is used, and the molten steel injection rate Q (m 3 / min) and the flow control excluding the hook portion On the condition that the area S1 (m 2 ) of the upper surface of the pad and the area S2 (m 2 ) of the bottom surface of the flow control pad satisfy the relational expression 0.5 <(Q / S2) × (S1 / S2) <5.0. A method for producing a highly clean steel slab for continuous casting is disclosed.

特開昭５３−６２３１号公報JP-A-53-6231 特開平１０−２１６９０９号公報Japanese Patent Laid-Open No. 10-216909 特表平９−５０５２４２号公報JP-T 9-505242 特開２００４−１０７７号公報JP 2004-1077 A 特開２００４−９８０６６号公報JP 2004-98066 A 特開２００４−１５４８０３号公報JP 2004-154803 A

特許文献１〜６によって、タンディッシュにおける介在物の浮上分離は大幅に改善され、堰を設置しない場合に比較して溶鋼の清浄性は大幅に向上した。特に、特許文献３〜６では、「開口部へ向けて内方に且つ上方に伸びる環状の内面」、または、「壁部の上端部位から壁部の囲み中心へ向かって伸びる庇状部」により、取鍋からタンディッシュへの溶鋼注入流は注入部位側に戻るように攪拌されることで、溶鋼注入流が減速され、介在物の浮上分離を阻害する、タンディッシュ内での短絡流及び高速流が解消されて、介在物の浮上に寄与している。   By patent documents 1-6, the floating separation of the inclusion in a tundish was improved significantly, and the cleanliness of the molten steel improved significantly compared with the case where a weir is not installed. In particular, in Patent Documents 3 to 6, “an annular inner surface extending inward and upward toward the opening portion” or “a hook-shaped portion extending from the upper end portion of the wall portion toward the surrounding center of the wall portion”. The molten steel injection flow from the ladle to the tundish is agitated so as to return to the injection site side, so that the molten steel injection flow is decelerated and the floating separation of inclusions is hindered. The flow has been eliminated, contributing to the rise of inclusions.

しかしながら、特許文献３〜６においても、未だ改善の余地がある。即ち、特許文献５を例にとれば、取鍋からの溶鋼注入流は、タンディッシュの底部から上方へ伸びる壁部に衝突することによって流れの向きを変え、更にその上部の庇状部によって注入部位側に戻るように攪拌されるが、溶鋼注入部位と障害物となる壁部つまり堰との距離及び堰の高さが適切でない場合には、取鍋からの溶鋼注入流は堰に衝突することなく、或いは衝突したとしても一部分のみが衝突し、溶鋼流出口から鋳型へ流出することになる。この場合には、堰の効果は得られず、タンディッシュ内での介在物の浮上分離の促進は期待できない。   However, Patent Documents 3 to 6 still have room for improvement. That is, taking Patent Document 5 as an example, the molten steel injection flow from the ladle changes the direction of the flow by colliding with the wall portion extending upward from the bottom of the tundish, and further injected by the bowl-shaped portion at the top thereof. If the distance between the molten steel injection site and the obstacle wall, that is, the weir, and the height of the weir are not appropriate, the molten steel injection flow from the ladle collides with the weir. Even if it collides, only a part collides and flows out from the molten steel outlet to the mold. In this case, the effect of the weir is not obtained, and the promotion of the floating separation of inclusions in the tundish cannot be expected.

本発明はこのような事情に鑑みてなされたもので、その目的とするところは、タンディッシュの溶鋼注入部位と溶鋼流出口との間に、タンディッシュ底部から上方に伸びる壁部と、該壁部の上端部位に前記溶鋼注入部位側を向く庇状部と、を有する堰を設置したタンディッシュを用いて連続鋳造するにあたり、庇状部を有する堰の設置位置及びこの堰の高さを最適化することで、介在物の浮上分離を従来に比較して確実に行うことができ、その結果、介在物起因の製品欠陥を大幅に低減することのできる、連続鋳造による高清浄度鋼鋳片の製造方法を提供することである。   The present invention has been made in view of such circumstances, and an object thereof is to provide a wall portion extending upward from the bottom of the tundish between the molten steel injection site of the tundish and the molten steel outlet, and the wall. When continuously casting using a tundish equipped with a weir with a bowl-shaped part facing the molten steel injection site side at the upper end part of the part, the installation position of the weir with the bowl-shaped part and the height of this weir are optimal The high-cleanness steel slab by continuous casting that enables the floating separation of inclusions to be performed more reliably than before, and as a result, product defects due to inclusions can be greatly reduced. It is to provide a manufacturing method.

上記課題を解決するための第１の発明に係る連続鋳造による高清浄度鋼鋳片の製造方法は、アルミニウムで脱酸された溶鋼を取鍋から一旦タンディッシュに注入し、次いでタンディッシュから鋳型に注入して鋼鋳片を連続鋳造するにあたり、取鍋からの溶鋼注入流がタンディッシュ底部に衝突する溶鋼注入部位と、タンディッシュから鋳型への溶鋼流出口との間に、前記溶鋼注入部位を四方向から囲むとともに、１．０ｍｍ以上の開口幅の切り欠きを一箇所以上有する、タンディッシュの底部から上方に伸びる壁部と、該壁部の上端部位に前記溶鋼注入部位側を向いた庇状部と、を有する堰が、下記の（１）式の関係を満たす条件の設置位置及び堰高さで配置されたタンディッシュを用いることを特徴とする。
０．３≦Ｘ／ｈ≦５．５…（１）
但し、（１）式において、ｈは、庇状部を有する堰の高さ（ｍｍ）、Ｘは、溶鋼注入部位から庇状部を有する堰の溶鋼注入部位側の壁面までの距離（ｍｍ）である。 A method for producing a high cleanliness steel slab by continuous casting according to the first invention for solving the above-mentioned problem is as follows: molten steel deoxidized with aluminum is once poured into a tundish from a ladle, and then cast from the tundish to a mold. In the continuous casting of the steel slab by injecting into the molten steel, between the molten steel injection site where the molten steel injection flow from the ladle collides with the bottom of the tundish and the molten steel outlet from the tundish to the mold, the molten steel injection site In the four directions and having at least one notch with an opening width of 1.0 mm or more, the wall portion extending upward from the bottom of the tundish, and the molten steel injection site side toward the upper end portion of the wall portion A weir having a hook-like portion is characterized by using a tundish arranged at an installation position and a weir height satisfying the relationship of the following expression (1).
0.3 ≦ X / h ≦ 5.5 (1)
However, in Formula (1), h is the height (mm) of the weir having the hook-shaped portion, and X is the distance (mm) from the molten steel injection site to the wall surface on the molten steel injection site side of the weir having the hook-shaped portion. It is.

第２の発明に係る連続鋳造による高清浄度鋼鋳片の製造方法は、第１の発明において、前記タンディッシュは、前記堰と前記溶鋼流出口との間に、下方に開口部を有する上堰または上方に開口部を有する下堰が、下記の（２）式の関係を満たす位置に少なくとも１つ配置されていることを特徴とする。
０．５≦ｄ／Ｘ≦１０…（２）
但し、（２）式において、ｄは、庇状部を有する堰の溶鋼注入部位側の壁面から該堰の溶鋼流出口側に隣り合う堰の溶鋼注入部位側の壁面までの距離（ｍｍ）、Ｘは、溶鋼注入部位から庇状部を有する堰の溶鋼注入部位側の壁面までの距離（ｍｍ）である。 The method for producing a high cleanliness steel slab by continuous casting according to the second invention is the first invention, wherein the tundish has an opening below the weir and the molten steel outlet. The weir or the lower weir having an opening above is arranged at a position satisfying the relationship of the following expression (2).
0.5 ≦ d / X ≦ 10 (2)
However, in the formula (2), d is the distance (mm) from the wall surface on the molten steel injection site side of the weir having the hook-shaped portion to the wall surface on the molten steel injection site side of the weir adjacent to the molten steel outlet side of the weir. X is the distance (mm) from the molten steel injection site to the wall surface on the molten steel injection site side of the weir having the hook-shaped portion.

第３の発明に係る連続鋳造による高清浄度鋼鋳片の製造方法は、第１または第２の発明において、前記取鍋から前記タンディッシュの溶鋼注入部位に、下記の（３）式の関係を満たす内径を有するロングノズルを用いて溶鋼を注入することを特徴とする。
０＜Ｚ≦２（Ｘ−Ｙ）…（３）
但し、（３）式において、Ｘは、溶鋼注入部位から庇状部を有する堰の溶鋼注入部位側の壁面までの距離（ｍｍ）、Ｙは、庇状部を有する堰の庇状部の幅（ｍｍ）、Ｚは、ロングノズルの内径（ｍｍ）である。 The method for producing a high cleanliness steel slab by continuous casting according to the third invention is the relationship of the following formula (3) from the ladle to the molten steel injection site of the tundish in the first or second invention: The molten steel is injected using a long nozzle having an inner diameter satisfying the above condition.
0 <Z ≦ 2 (XY) (3)
However, in the formula (3), X is the distance (mm) from the molten steel injection site to the wall surface on the molten steel injection site side of the weir having the hook-like portion, and Y is the width of the hook-like portion of the weir having the hook-like portion. (Mm) and Z are inner diameters (mm) of the long nozzle.

第４の発明に係る連続鋳造による高清浄度鋼鋳片の製造方法は、第３の発明において、前記ロングノズルを、下記の（４）式の関係を満たす浸漬深さで、タンディッシュ内の溶鋼に浸漬しながら鋳造することを特徴とする。
０．３≦ｍ／Ｘ≦２．５…（４）
但し、（４）式において、ｍは、ロングノズルのタンディッシュ内溶鋼への浸漬深さ（ｍｍ）、Ｘは、溶鋼注入部位から庇状部を有する堰の溶鋼注入部位側の壁面までの距離（ｍｍ）である。 According to a fourth aspect of the present invention, there is provided a method for producing a high cleanliness steel slab by continuous casting. In the third aspect of the invention, the long nozzle is immersed in the tundish at an immersion depth satisfying the relationship of the following expression (4). It is characterized by casting while immersed in molten steel.
0.3 ≦ m / X ≦ 2.5 (4)
However, in the formula (4), m is the immersion depth (mm) in the molten steel in the tundish of the long nozzle, and X is the distance from the molten steel injection site to the wall surface on the molten steel injection site side of the weir having the hook-shaped portion. (Mm).

本発明によれば、庇状部を有する堰の設置位置及び堰高さを、これら双方を考慮して最適化するので、タンディッシュにおける介在物の浮上分離が促進され、鋳型に注入される溶鋼の清浄性が高まり、連続鋳造される鋼鋳片の清浄度が向上して、介在物起因の製品欠陥を大幅に低減することが実現される。   According to the present invention, since the installation position and the weir height of the weir having the bowl-shaped portion are optimized in consideration of both of them, the floating separation of inclusions in the tundish is promoted, and the molten steel injected into the mold This improves the cleanliness of the steel slab, improves the cleanliness of continuously cast steel slabs, and significantly reduces product defects due to inclusions.

本発明の実施の形態を示す図であって、連続鋳造設備のタンディッシュ及び鋳型の部分を示す側断面概略図である。It is a figure which shows embodiment of this invention, Comprising: It is a side cross-sectional schematic diagram which shows the part of the tundish and casting_mold | template of a continuous casting installation. 図１に示すタンディッシュの平面図である。It is a top view of the tundish shown in FIG.

以下、添付図面を参照して本発明を具体的に説明する。図１は、本発明の実施の形態を示す図であって、連続鋳造設備のタンディッシュ及び鋳型の部分を示す側断面概略図、図２は、図１に示すタンディッシュの平面図である。   Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a view showing an embodiment of the present invention, and is a schematic side sectional view showing a tundish and a mold part of a continuous casting facility, and FIG. 2 is a plan view of the tundish shown in FIG.

図１及び図２において、符号１はタンディッシュ、２は鋳型、３は取鍋（図示せず）の底部に取り付けられたロングノズル、４はタンディッシュの底部に取り付けられた浸漬ノズルであり、予めアルミニウムで脱酸され、取鍋内に収容された溶鋼１３がロングノズル３を介してタンディッシュ１に注入されながら、タンディッシュ内に所定量の溶鋼１３を滞留させた状態で、タンディッシュ内の溶鋼１３が浸漬ノズル４を介して鋳型２に注入されて、鋼鋳片１４が製造されている。これらの図は、２基の鋳型２で、２条（２ストランド）のスラブ鋳片を連続鋳造する図である。   1 and 2, reference numeral 1 is a tundish, 2 is a mold, 3 is a long nozzle attached to the bottom of a ladle (not shown), 4 is an immersion nozzle attached to the bottom of the tundish, The molten steel 13 previously deoxidized with aluminum and accommodated in the ladle is poured into the tundish 1 through the long nozzle 3 while a predetermined amount of molten steel 13 is retained in the tundish. The molten steel 13 is injected into the mold 2 through the immersion nozzle 4 to manufacture a steel slab 14. These drawings are diagrams in which two slab slabs are continuously cast with two molds 2.

本発明で使用するタンディッシュ１は、図１及び図２に示すように、取鍋（図示せず）からロングノズル３を介してタンディッシュ１に注入される溶鋼注入流がタンディッシュ１の底部に衝突する位置である溶鋼注入部位５と、タンディッシュ１から鋳型２への溶鋼流出口６との間に、タンディッシュ１の底部から上方に伸びる壁部８と、壁部８の上端部位に溶鋼注入部位側を向いて水平方向に突出した庇状部９と、を有する堰７が配置されている。堰７は、溶鋼注入部位５を囲むように、タンディッシュ１の長辺面側にも配置されている。つまり、溶鋼注入部位５は、外殻が正方形或いは長方形の四角形の堰７によって四方向から囲まれている。但し、堰７には、壁部８及び庇状部９を貫通する、１．０ｍｍ以上の開口幅の切り欠き１０が少なくも一箇所は設けられており、鋳造終了時には、堰７で囲まれる空間内の溶鋼１３が、溶鋼流出口６を向いて排出されるように構成されている。切り欠き１０の開口幅を大きくすると堰７の効果が低下するので、切り欠き１０の開口幅は３０ｍｍ以下とすることが好ましい。   As shown in FIGS. 1 and 2, the tundish 1 used in the present invention is a bottom portion of the tundish 1 where a molten steel injection flow injected from a ladle (not shown) into the tundish 1 through the long nozzle 3 is provided. Between the molten steel injection site 5 which is a position where it collides with the molten steel and the molten steel outlet 6 from the tundish 1 to the mold 2, the wall 8 extending upward from the bottom of the tundish 1, and the upper end of the wall 8 A weir 7 having a hook-like portion 9 that protrudes in the horizontal direction facing the molten steel injection site is disposed. The weir 7 is also arranged on the long side surface side of the tundish 1 so as to surround the molten steel injection site 5. That is, the molten steel injection site 5 is surrounded from four directions by the square weir 7 whose outer shell is square or rectangular. However, the weir 7 is provided with at least one notch 10 having an opening width of 1.0 mm or more that penetrates the wall portion 8 and the bowl-shaped portion 9 and is surrounded by the weir 7 at the end of casting. The molten steel 13 in the space is configured to be discharged toward the molten steel outlet 6. Since the effect of the weir 7 is reduced when the opening width of the notch 10 is increased, the opening width of the notch 10 is preferably 30 mm or less.

ロングノズル３を介して溶鋼注入部位５に注入された溶鋼１３は、溶鋼注入部位５に衝突した後、溶鋼注入流の落下エネルギーによってタンディッシュ１の底面に沿って四方を向いて流れるが、堰７の壁部８に衝突して上向き方向となり、更に、堰７の庇状部９によって溶鋼注入部位５を向いた流れになる。溶鋼注入部位５を向いた、四方から来る流れは、互いに衝突し合い、運動エネルギーを消費して減速する。即ち、堰７によって、ロングノズル３を介して注入された高速の溶鋼流は大幅に減速されると同時に、タンディッシュ内の溶鋼流が均一化される。これにより、タンディッシュ内での短絡流及び高速流が解消されて、これらの流れに随伴して溶鋼流出口６から鋳型２に流出する介在物が減少する。つまり、タンディッシュ１における介在物の浮上分離が促進される。   After the molten steel 13 injected into the molten steel injection site 5 through the long nozzle 3 collides with the molten steel injection site 5, it flows in four directions along the bottom surface of the tundish 1 due to the falling energy of the molten steel injection flow. 7 and collides with the wall portion 8 in the upward direction, and further flows toward the molten steel injection site 5 by the hook-shaped portion 9 of the weir 7. Flows coming from four directions facing the molten steel injection site 5 collide with each other and consume kinetic energy and decelerate. That is, the high-speed molten steel flow injected through the long nozzle 3 is greatly decelerated by the weir 7, and at the same time, the molten steel flow in the tundish is made uniform. Thereby, the short circuit flow and the high-speed flow in the tundish are eliminated, and the inclusions flowing out from the molten steel outlet 6 to the mold 2 are reduced accompanying these flows. That is, the floating separation of inclusions in the tundish 1 is promoted.

但し、この堰７による作用・効果を得るためには、堰７を、その設置位置及び堰高さが下記の（１）を満足する条件で配置する必要がある。即ち、溶鋼注入部位５から堰７の溶鋼注入部位側の壁面までの距離をＸ（ｍｍ）とし、堰７の高さをｈ（ｍｍ）とすると、距離Ｘと堰高さｈとが、下記の（１）式の関係を満足する範囲内で配置する必要がある。
０．３≦Ｘ／ｈ≦５．５…（１）
Ｘ／ｈが０．３未満の場合は、溶鋼注入部位５と堰７との距離が短くなり、換言すれば、堰７で囲まれる空間が狭くなり、堰７の庇状部９による効果をほとんど得られず、堰７で囲まれた空間における溶鋼の減衰効果が期待できない。一方、Ｘ／ｈが５．５を超えると、溶鋼注入部位５と堰７との距離が長くなり、タンディッシュ底面に沿った流れが浮上して、堰７に衝突しないまま堰７を通り過ぎることが起こり、堰７の効果が得られないことが発生する。 However, in order to obtain the action and effect of the weir 7, it is necessary to arrange the weir 7 under the condition that the installation position and the weir height satisfy the following (1). That is, if the distance from the molten steel injection site 5 to the wall surface on the molten steel injection site side of the weir 7 is X (mm) and the height of the weir 7 is h (mm), the distance X and the weir height h are as follows: It is necessary to arrange within the range that satisfies the relationship of the expression (1).
0.3 ≦ X / h ≦ 5.5 (1)
When X / h is less than 0.3, the distance between the molten steel injection site 5 and the weir 7 is shortened. In other words, the space surrounded by the weir 7 is narrowed, and the effect of the hook-like portion 9 of the weir 7 is reduced. It is hardly obtained, and the damping effect of the molten steel in the space surrounded by the weir 7 cannot be expected. On the other hand, if X / h exceeds 5.5, the distance between the molten steel injection site 5 and the weir 7 becomes longer, the flow along the tundish bottom surface rises, and passes through the weir 7 without colliding with the weir 7. Occurs, and the effect of the weir 7 cannot be obtained.

ここで、堰７は、上方に溶鋼１３が存在することを前提とした堰であり、従って、堰７の高さｈは、少なくとも、堰７を配置する位置でのタンディッシュ内の溶鋼深さ未満とすることが必要である。また、好ましくは、堰７の高さｈは、堰７を配置する位置でのタンディッシュ内の溶鋼深さの１／２以下とする。一方、堰７の高さｈが余りに低いと、堰７の効果が得られないので、高さｈは２００ｍｍ以上確保することが好ましい。   Here, the weir 7 is a weir on the premise that the molten steel 13 exists above. Therefore, the height h of the weir 7 is at least the depth of the molten steel in the tundish at the position where the weir 7 is disposed. It is necessary to make it less than. In addition, preferably, the height h of the weir 7 is set to ½ or less of the molten steel depth in the tundish at the position where the weir 7 is disposed. On the other hand, if the height h of the weir 7 is too low, the effect of the weir 7 cannot be obtained. Therefore, it is preferable to secure the height h of 200 mm or more.

また、実際の溶鋼注入部位５は「点」ではなく、或る程度の面積を持っており、このような溶鋼注入部位を四方から囲むと同時に、堰７で囲まれる空間の絶対量を確保するために、（１）式を満足した上で、距離Ｘを３００ｍｍ以上確保することが好ましい。尚、図１では、面積を有する溶鋼注入部位の中心位置を、溶鋼注入部位５として表示している。   In addition, the actual molten steel injection site 5 is not a “point” but has a certain area, and such a molten steel injection site is surrounded from all sides, and at the same time, the absolute amount of the space surrounded by the weir 7 is ensured. Therefore, it is preferable that the distance X is 300 mm or more while satisfying the expression (1). In addition, in FIG. 1, the center position of the molten steel injection | pouring site | part which has an area is displayed as the molten steel injection | pouring site | part 5. FIG.

また、本発明で使用するタンディッシュ１は、堰７と溶鋼流出口６との間に、下方に開口部を有する上堰または上方に開口部を有する下堰を、下記の（２）式の関係を満たす位置に少なくとも１つ配置することが好ましい。
０．５≦ｄ／Ｘ≦１０…（２）
但し、（２）式において、ｄは、堰７の溶鋼注入部位側の壁面から堰７の溶鋼流出口側に隣り合う堰の溶鋼注入部位側の壁面までの距離（ｍｍ）、Ｘは、溶鋼注入部位５から堰７の溶鋼注入部位側の壁面までの距離（ｍｍ）である。 Further, the tundish 1 used in the present invention has an upper weir having an opening part below or a lower weir having an opening part above the weir 7 and the molten steel outlet 6 in the following formula (2). It is preferable to arrange at least one at a position that satisfies the relationship.
0.5 ≦ d / X ≦ 10 (2)
However, in the formula (2), d is the distance (mm) from the wall surface on the molten steel injection site side of the weir 7 to the wall surface on the molten steel injection site side of the weir adjacent to the molten steel outlet side of the weir 7, and X is the molten steel This is the distance (mm) from the injection site 5 to the wall surface of the weir 7 on the molten steel injection site side.

ｄ／Ｘが０．５未満の場合、堰７の庇状部９による溶鋼流動上昇効果が得られないうちに次の堰に溶鋼１３が至るため、介在物の浮上効果が損なわれる。一方、ｄ／Ｘが１０を超えても、介在物の浮上分離効果は飽和し、それ以上に大きくする必要がない。また、ｄ／Ｘを過剰に大きくすると、長辺面の長いタンディッシュが必要になるという問題点もある。図１及び図２に示すタンディッシュ１では、（２）式を満たす位置に、堰７の側から順に上堰１１及び下堰１２を、タンディッシュ１の溶鋼注入部位５を挟んだ両側に配置している。   When d / X is less than 0.5, since the molten steel 13 reaches the next weir before the effect of increasing the molten steel flow by the bowl-shaped portion 9 of the weir 7 is obtained, the floating effect of inclusions is impaired. On the other hand, even if d / X exceeds 10, the floating separation effect of inclusions is saturated and does not need to be increased further. Further, when d / X is excessively increased, there is a problem that a tundish having a long side surface is required. In the tundish 1 shown in FIG. 1 and FIG. 2, the upper weir 11 and the lower weir 12 are arranged on both sides of the tundish 1 with the molten steel injection site 5 in order from the side of the weir 7 at a position satisfying the expression (2). doing.

図１に示す、堰７、上堰１１及び下堰１２を有するタンディッシュ１を使用して溶鋼１３を連続鋳造すると、ロングノズル３から注入された溶鋼中の介在物は、堰７により上向き方向の流動を得て、タンディッシュ内の溶鋼湯面に浮上する。また、溶鋼湯面に浮上しなかった介在物は、その後、溶鋼流に乗って上堰１１の溶鋼湯面近傍の壁部に至り、溶鋼流は、上堰１１によって上向き及び下向きの流れに別れる。上向き流れの溶鋼中の介在物は、溶鋼湯面に浮上し、一方、下向き流れの溶鋼中の介在物は、上堰１１のタンディッシュ底部近傍の開口部分から溶鋼流出口６の方向に流れ出る。その後、上堰１１の外側にある下堰１２により、流れが上向き方向となり、溶鋼湯面への介在物の浮上が促進される。つまり、堰７、上堰１１及び下堰１２によって溶鋼中の介在物の浮上分離が促進される。   When the molten steel 13 is continuously cast using the tundish 1 having the weir 7, the upper weir 11, and the lower weir 12 shown in FIG. 1, inclusions in the molten steel injected from the long nozzle 3 are directed upward by the weir 7. It floats on the molten steel surface in the tundish. The inclusions that have not floated on the molten steel surface then ride on the molten steel flow and reach the wall near the molten steel surface of the upper weir 11, and the molten steel flow is separated into upward and downward flows by the upper weir 11. . Inclusions in the upward flowing molten steel float on the surface of the molten steel, while inclusions in the downward flowing molten steel flow out from the opening near the bottom of the tundish of the upper weir 11 toward the molten steel outlet 6. Thereafter, the flow is directed upward by the lower weir 12 outside the upper weir 11, and the floating of inclusions on the molten steel surface is promoted. That is, the weir 7, the upper weir 11 and the lower weir 12 promote the floating separation of inclusions in the molten steel.

使用するロングノズル３は、その内径が以下の（３）式の条件を満足することが好ましい。
０＜Ｚ≦２（Ｘ−Ｙ）…（３）
但し、（３）式において、Ｘは、溶鋼注入部位５から堰７の溶鋼注入部位側の壁面までの距離（ｍｍ）、Ｙは、堰７の庇状部９の幅（ｍｍ）、Ｚは、ロングノズル３の内径（ｍｍ）である。 The long nozzle 3 to be used preferably has an inner diameter that satisfies the condition of the following expression (3).
0 <Z ≦ 2 (XY) (3)
However, in Formula (3), X is the distance (mm) from the molten steel injection | pouring site | part 5 to the wall surface by the side of the molten steel injection | pouring site | part of the weir 7, Y is the width (mm) of the bowl-shaped part 9 of the weir 7, Z is The inner diameter (mm) of the long nozzle 3.

Ｚが２（Ｘ−Ｙ）を超える場合には、ロングノズル３の内径が相対する庇状部９の間隔よりも大きくなり、ロングノズル３からの溶鋼注入流が堰７の外側に注入されることも起こり、堰７の効果を十分に発揮できず、好ましくない。   When Z exceeds 2 (X−Y), the inner diameter of the long nozzle 3 becomes larger than the interval between the opposing flanges 9, and the molten steel injection flow from the long nozzle 3 is injected outside the weir 7. This is not preferable because the effect of the weir 7 cannot be sufficiently exhibited.

また、ロングノズル３を、堰７の設置位置に対して以下の（４）式の関係を満たす浸漬深さで、タンディッシュ内の溶鋼１３に浸漬させることが好ましい。
０．３≦ｍ／Ｘ≦２．５…（４）
但し、（４）式において、ｍは、ロングノズル３のタンディッシュ内溶鋼への浸漬深さ（ｍｍ）、Ｘは、溶鋼注入部位５から堰７の溶鋼注入部位側の壁面までの距離（ｍｍ）である。 Moreover, it is preferable to immerse the long nozzle 3 in the molten steel 13 in the tundish at an immersion depth that satisfies the relationship of the following expression (4) with respect to the installation position of the weir 7.
0.3 ≦ m / X ≦ 2.5 (4)
However, in Formula (4), m is the immersion depth (mm) in the molten steel in the tundish of the long nozzle 3, and X is the distance (mm) from the molten steel injection site 5 to the wall surface on the molten steel injection site side of the weir 7 ).

ｍ／Ｘが、０．３未満の場合は、タンディッシュ底面に沿った溶鋼流れが、堰７で囲まれる空間に十分に入り込まないため、堰７を十分に活用できず、堰７による介在物浮上促進効果を十分に得ることができない。一方、ｍ／Ｘが２．５を超える場合は、堰７の空間内で、注入された溶鋼流動を十分に減衰することができず、堰７の効果が乏しくなるために好ましくない。   When m / X is less than 0.3, the molten steel flow along the bottom surface of the tundish does not sufficiently enter the space surrounded by the weir 7, so that the weir 7 cannot be fully utilized, and inclusions by the weir 7 The effect of promoting levitation cannot be obtained sufficiently. On the other hand, when m / X exceeds 2.5, the injected molten steel flow cannot be sufficiently attenuated in the space of the weir 7 and the effect of the weir 7 becomes poor.

以上説明したように、本発明によれば、庇状部９を有する堰７の設置位置及び堰高さを、これら双方を考慮して最適化するので、タンディッシュ１における介在物の浮上分離が促進され、鋳型２に注入される溶鋼１３の清浄性が高まり、鋼鋳片１４の清浄度が向上して、介在物起因の製品欠陥を大幅に低減することが実現される。   As described above, according to the present invention, since the installation position and the weir height of the weir 7 having the hook-like portion 9 are optimized in consideration of both of them, the floating separation of the inclusions in the tundish 1 is prevented. As a result, the cleanliness of the molten steel 13 injected into the mold 2 is enhanced, the cleanliness of the steel slab 14 is improved, and product defects due to inclusions are greatly reduced.

転炉での溶銑の脱炭精錬及びその後のＲＨ真空脱ガス装置での真空脱ガス精錬によって溶製した約２５０トンのアルミキルド極低炭素鋼を、図１に示す構成の容量７０トンのタンディッシュを有するスラブ連続鋳造機を用いて、溶鋼注入速度を５．０トン／(ｍｉｎ・ストランド)として鋼のスラブ鋳片に連続鋳造する試験を実施した。   About 250 tons of aluminum-killed ultra-low carbon steel melted by decarburization and refining of hot metal in the converter and subsequent vacuum degassing and refining in the RH vacuum degassing unit, is a tundish with a capacity of 70 tons having the configuration shown in FIG. Using a slab continuous casting machine having a slab, a test for continuously casting a steel slab slab at a molten steel injection speed of 5.0 tons / (min · strand) was performed.

その際に、堰７の設置位置（Ｘ＝溶鋼注入部位５から堰７の溶鋼注入部位側の壁面までの距離）及び堰高さ（ｈ）、上堰１１の設置位置（ｄ＝堰７の溶鋼注入部位側の壁面から堰７の溶鋼流出口側に隣り合う堰の溶鋼注入部位側の壁面までの距離）、使用するロングノズルの内径（Ｚ）、ロングノズルの浸漬深さ（ｍ）を種々変更した（水準１〜１１）。また、比較のために、堰７を配置していない以外は、水準１と同一のタンディッシュを使用した鋳造試験も実施した（水準１２：従来例）。堰７の切り欠きの開口幅は全て１０ｍｍとした。鋳造後、超音波探傷測定により鋳片の介在物数を調査した。   At that time, the installation position of the weir 7 (X = distance from the molten steel injection site 5 to the wall surface on the molten steel injection site side of the weir 7) and the height of the weir (h), the installation position of the upper weir 11 (d = of the weir 7 Distance from the wall on the molten steel injection site side to the wall on the molten steel injection site side of the weir adjacent to the molten steel outlet side of the weir 7, the inner diameter (Z) of the long nozzle used, and the immersion depth (m) of the long nozzle Various changes were made (levels 1 to 11). For comparison, a casting test was also performed using the same tundish as that of Level 1 except that the weir 7 was not disposed (Level 12: conventional example). All the opening widths of the notches of the weir 7 were 10 mm. After casting, the number of inclusions in the slab was examined by ultrasonic flaw detection.

表１に、使用したタンディッシュの各種寸法及び鋳片の介在物調査結果を示す。尚、介在物調査結果は、堰７を配置していないタンディッシュを使用した水準１２の測定値を基準として指数化して表示した。また、備考欄に、水準１〜１１において、本発明の範囲の試験は「本発明例」と表示し、それ以外は「比較例」と表示した。   Table 1 shows the various dimensions of the tundish used and the results of investigation of inclusions in the slab. In addition, the inclusion investigation result was displayed as an index based on the measurement value of the level 12 using the tundish where the weir 7 is not arranged. Moreover, in the remarks column, in the level 1-11, the test of the range of this invention was displayed as "invention example", and the others were displayed as "comparative example".

Figure 0005556421
Figure 0005556421

表１に示すように、本発明を適用することで、スラブ鋳片の介在物数を大幅に削減できることが確認できた。つまり、本発明を適用することにより、タンディッシュにおける介在物の浮上効果を大幅に促進できることが確認できた。   As shown in Table 1, it was confirmed that the number of inclusions in the slab slab can be significantly reduced by applying the present invention. That is, by applying the present invention, it has been confirmed that the floating effect of inclusions in the tundish can be greatly promoted.

１ タンディッシュ
２ 鋳型
３ ロングノズル
４ 浸漬ノズル
５ 溶鋼注入部位
６ 溶鋼流出口
７ 堰
８ 壁部
９ 庇状部
１０ 切り欠き
１１ 上堰
１２ 下堰
１３ 溶鋼
１４ 鋼鋳片 DESCRIPTION OF SYMBOLS 1 Tundish 2 Mold 3 Long nozzle 4 Immersion nozzle 5 Molten steel injection | pouring site 6 Molten steel outlet 7 Weir 8 Wall part 9 Ridge part 10 Notch 11 Upper weir 12 Lower weir 13 Molten steel 14 Steel slab

Claims (2)

アルミニウムで脱酸された溶鋼を取鍋から一旦タンディッシュに注入し、次いでタンディッシュから鋳型に注入して鋼鋳片を連続鋳造するにあたり、
取鍋からの溶鋼注入流がタンディッシュ底部に衝突する溶鋼注入部位と、タンディッシュから鋳型への溶鋼流出口との間に、前記溶鋼注入部位を四方向から囲むとともに、１．０ｍｍ以上の開口幅の切り欠きを一箇所以上有する、タンディッシュの底部から上方に伸びる壁部と、該壁部の上端部位に前記溶鋼注入部位側を向いた庇状部と、を有する堰が、下記の（１）式の関係を満たす条件の設置位置及び堰高さで配置されたタンディッシュを用い、
前記取鍋から前記タンディッシュの溶鋼注入部位に、下記の（３）式の関係を満たす内径を有するロングノズルを用いて溶鋼を注入し、且つ、前記ロングノズルを、下記の（４）式の関係を満たす浸漬深さで、タンディッシュ内の溶鋼に浸漬しながら鋳造することを特徴とする、連続鋳造による高清浄度鋼鋳片の製造方法。
０．３≦Ｘ／ｈ≦５．５…（１）
０＜Ｚ≦２（Ｘ−Ｙ）…（３）
０．３≦ｍ／Ｘ≦２．５…（４）
但し、（１）式、（３）式、（４）式において、ｈは、庇状部を有する堰の高さ（ｍｍ）、Ｘは、溶鋼注入部位から庇状部を有する堰の溶鋼注入部位側の壁面までの距離（ｍｍ）、Ｙは、庇状部を有する堰の庇状部の幅（ｍｍ）、Ｚは、ロングノズルの内径（ｍｍ）、ｍは、ロングノズルのタンディッシュ内溶鋼への浸漬深さ（ｍｍ）である。 When the molten steel deoxidized with aluminum is once poured into the tundish from the pan, and then poured into the mold from the tundish to continuously cast the steel slab,
Between the molten steel injection site where the molten steel injection flow from the ladle collides with the bottom of the tundish and the molten steel outlet from the tundish to the mold, the molten steel injection site is surrounded from four directions and an opening of 1.0 mm or more A weir having one or more width notches and having a wall portion extending upward from the bottom of the tundish, and a bowl-shaped portion facing the molten steel injection site side at the upper end portion of the wall portion, 1) Using a tundish arranged at the installation position and weir height that satisfy the relationship of the equation ,
The molten steel is injected from the ladle into the molten steel injection site of the tundish using a long nozzle having an inner diameter satisfying the relationship of the following expression (3), and the long nozzle is replaced by the following expression (4): method of manufacturing an immersion depth that satisfies the relationship, which is characterized that you cast while immersed in the molten steel in the tundish, high cleanliness steel slabs by continuous casting.
0.3 ≦ X / h ≦ 5.5 (1)
0 <Z ≦ 2 (XY) (3)
0.3 ≦ m / X ≦ 2.5 (4)
However, in the formulas (1) , (3), and (4) , h is the height (mm) of the weir having the hook-shaped portion, and X is the molten steel injection of the weir having the hook-shaped portion from the molten steel injection site. Distance to the wall on the part side (mm) , Y is the width (mm) of the rod-shaped portion of the weir with the rod-shaped portion, Z is the inner diameter (mm) of the long nozzle, m is in the tundish of the long nozzle It is the immersion depth (mm) in molten steel . 前記タンディッシュは、前記堰と前記溶鋼流出口との間に、下方に開口部を有する上堰または上方に開口部を有する下堰が、下記の（２）式の関係を満たす位置に少なくとも１つ配置されていることを特徴とする、請求項１に記載の連続鋳造による高清浄度鋼鋳片の製造方法。
０．５≦ｄ／Ｘ≦１０…（２）
但し、（２）式において、ｄは、庇状部を有する堰の溶鋼注入部位側の壁面から該堰の溶鋼流出口側に隣り合う堰の溶鋼注入部位側の壁面までの距離（ｍｍ）、Ｘは、溶鋼注入部位から庇状部を有する堰の溶鋼注入部位側の壁面までの距離（ｍｍ）である。 The tundish is at least 1 in a position where the upper weir having an opening below or the lower weir having an opening above satisfies the relationship of the following expression (2) between the weir and the molten steel outlet. The method for producing a high cleanliness steel slab by continuous casting according to claim 1, wherein two are arranged.
0.5 ≦ d / X ≦ 10 (2)
However, in the formula (2), d is the distance (mm) from the wall surface on the molten steel injection site side of the weir having the hook-shaped portion to the wall surface on the molten steel injection site side of the weir adjacent to the molten steel outlet side of the weir. X is the distance (mm) from the molten steel injection site to the wall surface on the molten steel injection site side of the weir having the hook-shaped portion.
JP2010142299A 2010-06-23 2010-06-23 Manufacturing method of high cleanliness steel slab by continuous casting Active JP5556421B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2010142299A JP5556421B2 (en) 2010-06-23 2010-06-23 Manufacturing method of high cleanliness steel slab by continuous casting

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2010142299A JP5556421B2 (en) 2010-06-23 2010-06-23 Manufacturing method of high cleanliness steel slab by continuous casting

Publications (2)

Publication Number Publication Date
JP2012006025A JP2012006025A (en) 2012-01-12
JP5556421B2 true JP5556421B2 (en) 2014-07-23

Family

ID=45537206

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2010142299A Active JP5556421B2 (en) 2010-06-23 2010-06-23 Manufacturing method of high cleanliness steel slab by continuous casting

Country Status (1)

Country Link
JP (1) JP5556421B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110270679A (en) * 2019-07-12 2019-09-24 南京钢铁股份有限公司 A kind of stream of bloom four tundish
JP7389335B2 (en) * 2019-12-04 2023-11-30 日本製鉄株式会社 Method for producing thin slabs
CN112191835B (en) * 2020-10-12 2024-04-19 武汉科技大学 Multi-stage bottom swirling type current stabilizer

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07164116A (en) * 1993-12-14 1995-06-27 Nippon Steel Corp Tundish for continuously casting steel and method of continuously casting steel for using this tundish
JPH08141709A (en) * 1994-11-22 1996-06-04 Nippon Steel Corp Tundish for continuously casting molten steel and continuous casting method using same
GB9913241D0 (en) * 1999-06-08 1999-08-04 Foseco Int Impact pad for tundish
JP4186660B2 (en) * 2002-04-12 2008-11-26 Ｊｆｅスチール株式会社 Flow control pad for molten metal in tundish
JP4023289B2 (en) * 2002-11-05 2007-12-19 Ｊｆｅスチール株式会社 Manufacturing method of high cleanliness steel slab by continuous casting

Also Published As

Publication number Publication date
JP2012006025A (en) 2012-01-12

Similar Documents

Publication Publication Date Title
JP5807719B2 (en) High cleanliness steel slab manufacturing method and tundish
JP5516235B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP5556421B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP4023289B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP5556465B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP5751078B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP5831124B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP4585504B2 (en) Method for continuous casting of molten metal
JP2005131661A (en) Method and equipment for continuously casting high cleanness steel by tundish
JP4725244B2 (en) Ladle for continuous casting and method for producing slab
JP4216642B2 (en) Immersion nozzle and continuous casting method using the same
JP5082700B2 (en) Steel continuous casting method
JP5831138B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP2006239746A (en) Tundish for continuous casting of steel
JP2014208376A (en) Method of manufacturing high cleanliness steel slab by continuous molding
JP2008254028A (en) Tundish for continuous casting
JP4998705B2 (en) Steel continuous casting method
JP4725245B2 (en) Continuous casting tundish and slab manufacturing method
JP5673162B2 (en) Continuous casting method and continuous casting apparatus
JP5440933B2 (en) Immersion nozzle and continuous casting method using the same
JP4319072B2 (en) Tundish with excellent inclusion levitation
JP7215361B2 (en) Continuous casting method
JP7269480B2 (en) Continuous casting method
JP2011194420A (en) Method of producing high cleanliness steel
JP2008132504A (en) Tundish for continuous casting

Legal Events

Date Code Title Description
RD03 Notification of appointment of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7423

Effective date: 20120321

RD04 Notification of resignation of power of attorney

Free format text: JAPANESE INTERMEDIATE CODE: A7424

Effective date: 20120327

A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20130419

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20140207

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20140218

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20140415

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20140507

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20140520

R150 Certificate of patent or registration of utility model

Ref document number: 5556421

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250