JP5025312B2 - Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner - Google Patents

Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner Download PDF

Info

Publication number
JP5025312B2
JP5025312B2 JP2007101580A JP2007101580A JP5025312B2 JP 5025312 B2 JP5025312 B2 JP 5025312B2 JP 2007101580 A JP2007101580 A JP 2007101580A JP 2007101580 A JP2007101580 A JP 2007101580A JP 5025312 B2 JP5025312 B2 JP 5025312B2
Authority
JP
Japan
Prior art keywords
casting
molten steel
ingot
runner
flow
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP2007101580A
Other languages
Japanese (ja)
Other versions
JP2008254058A (en
Inventor
剛 谷口
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.)
Sanyo Special Steel Co Ltd
Original Assignee
Sanyo Special Steel Co Ltd
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 Sanyo Special Steel Co Ltd filed Critical Sanyo Special Steel Co Ltd
Priority to JP2007101580A priority Critical patent/JP5025312B2/en
Publication of JP2008254058A publication Critical patent/JP2008254058A/en
Application granted granted Critical
Publication of JP5025312B2 publication Critical patent/JP5025312B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Molds, Cores, And Manufacturing Methods Thereof (AREA)

Description

この発明は、取鍋と下注造塊用鋳型への注入管の接続部に大気が侵入しないように該接続部分をシールする不活性なシールガスが該接続部分から注入管および湯道を通じて下注造塊用鋳型内へ流入するが、この流入したシールガスを湯道に連接する複数の下注造塊用鋳型に分散させることで各下注造塊用鋳型に流入するシールガス量を減少して得られた鋼塊の表面肌を改善する下注造塊用鋳型への注湯方法に関する。   In the present invention, an inert sealing gas for sealing the connection portion so that the atmosphere does not enter the connection portion of the injection pipe to the ladle and the mold for ingot casting is dropped from the connection portion through the injection pipe and the runner. It flows into the casting ingot mold, but the amount of seal gas flowing into each casting mold is reduced by dispersing the flowing seal gas in multiple casting molds connected to the runner. It is related with the pouring method to the mold for undercast ingot which improves the surface skin of the steel ingot obtained by doing this.

大気中で溶鋼を下注造塊用鋳型で鋳造する際に、大気中の酸素と溶鋼成分の反応によって酸化物系介在物が生成するのを防止するため、取鍋の溶鋼開閉ゲート部に設けたフードと注入管の上部入口との間にアルゴンや窒素などの不活性ガスをシールガスとして吹き込み、溶鋼と大気の接触を防止することが行なわれている。   In order to prevent the formation of oxide inclusions due to the reaction between oxygen and molten steel components in the atmosphere when casting molten steel in the mold for casting ingots in the atmosphere, it is provided at the molten steel opening and closing gate of the ladle. An inert gas such as argon or nitrogen is blown as a sealing gas between the hood and the upper inlet of the injection tube to prevent contact between the molten steel and the atmosphere.

取鍋のフード部分から吹き込まれたシールガスは、注入管内で溶鋼の流れに巻込まれて注入管および湯道を通過して気泡となって下注造塊用鋳型内に流入し、下注造塊用鋳型を通じて大気中に放出される。シールガスの気泡が下注造塊用鋳型内に流入しない場合は、下注造塊用鋳型内で溶鋼の表面は水平なまま溶鋼面は鋳造の進行に伴って静かに上昇してゆく。しかし、シールガスの気泡が下注造塊用鋳型内に流入する場合は、シールガスの気泡が浮上して溶鋼の表面から離脱する際に、気泡が下注造塊用鋳型内の溶鋼の表面を盛り上げたりあるいは弾けたりして溶鋼の表面に大きな揺らぎ（ボイリング）が生じる。溶鋼の表面に大きな揺らぎが生じた時には、溶鋼の波やスプラッシュが下注造塊用鋳型内壁の溶鋼面位置より高い位置で凝固し、この先行して凝固した位置の内壁面の部分に溶鋼面が上昇して本体が凝固する。この結果、鋼塊の表面が二重肌になったり、あるいは溶鋼の表面を覆っている被覆材の溶融層と未溶融層が混合されて未溶融の被覆材を鋳型と溶鋼の間に巻込んで凝固し、鋼塊の表面に凹みや肌荒れを生じたりするなど、鋼塊の表面肌の悪化が発生し易い。その他、溶鋼の表面を覆っている被覆材を溶鋼中に巻込み、巻込まれた被覆材が溶鋼から浮上分離しきらず、鋼塊表層の初期凝固シェルにトラップされたまま凝固してしまうおそれもある。特にシールガスとしてアルゴンガスを用いた場合には、窒素ガスを用いた場合と比べて、シールガスの巻込みによる下注造塊用鋳型内の溶鋼の表面の揺らぎが顕著に発生する。この場合、シールガスの巻込みによる下注造塊用鋳型内の溶鋼の表面の揺らぎは、特に注入管の直近の下注造塊用鋳型内で起こり易い。   The seal gas blown from the hood part of the ladle is wound into the molten steel flow in the injection pipe, passes through the injection pipe and the runner, becomes a bubble, and flows into the casting mold for the lower casting ingot. Released into the atmosphere through the lump mold. In the case where the seal gas bubbles do not flow into the lower casting ingot mold, the molten steel surface rises gently with the progress of casting while the surface of the molten steel remains horizontal in the lower casting ingot mold. However, if the seal gas bubbles flow into the mold for ingot casting, the bubbles will rise to the surface of the molten steel in the mold for ingot casting when the bubbles rise and leave the surface of the molten steel. A large fluctuation (boiling) is generated on the surface of the molten steel by raising or flipping the steel. When large fluctuations occur on the surface of the molten steel, the molten steel wave and splash solidify at a position higher than the position of the molten steel surface of the inner wall of the mold for casting ingot, and the surface of the molten steel is formed on the inner wall portion at the position where the solidification has occurred earlier. Rises and the body solidifies. As a result, the surface of the steel ingot has a double skin, or the molten layer and unmelted layer of the coating material covering the molten steel surface are mixed and the unmelted coating material is wound between the mold and the molten steel. The surface of the steel ingot is liable to deteriorate, for example, the surface of the steel ingot is solidified and the surface of the steel ingot is dented or rough. In addition, the coating material covering the surface of the molten steel is wound into the molten steel, and the wrapped coating material may not float and separate from the molten steel and may solidify while trapped in the initial solidification shell of the steel ingot surface layer. . In particular, when argon gas is used as the seal gas, fluctuations in the surface of the molten steel in the casting for ingot casting due to the entrapment of the seal gas are significantly generated as compared with the case where nitrogen gas is used. In this case, the fluctuation of the surface of the molten steel in the casting for ingot casting due to the entrapment of the seal gas is likely to occur particularly in the casting for casting ingot in the immediate vicinity of the injection pipe.

この現象を防止するための従来の技術には、注入管を太径化して注入管内の流速を低減することで溶鋼中のシールガスの浮上を促進し、シールガスの下注造塊用鋳型内への流入を低減するボイリング抑制造塊方法（例えば、特許文献１参照。）や、注入管とその直近の下注造塊用鋳型を結ぶ湯道の間にガス抜き管を立てることで、シールガスの下注造塊用鋳型内への流入を防止する下注造塊法がある（例えば、特許文献２参照。）。   The conventional technique for preventing this phenomenon is to increase the diameter of the injection pipe and reduce the flow velocity in the injection pipe to promote the rising of the seal gas in the molten steel, and the inside of the casting gas casting mold Boiling suppression ingot-making method (see, for example, Patent Document 1) for reducing the inflow into the pipe, and a degassing pipe standing between the injection pipe and the casting mold for the immediate ingot-making ingot. There is a lower casting ingot method that prevents gas from flowing into the casting mold (see, for example, Patent Document 2).

しかし、特許文献１に記載の注入管を太径化する方法では、シールガスの注入管内へ流さずに、シール体により大気の流入を防止した状態であっても、下注造塊用鋳型内へのシールガスの流入を防止して表面肌不良を皆無にすることはできておらず、一方、シール体無しで大気の巻込みがある状態では、シール体有りの場合よりも多くの表面肌不良が発生している。このことから、シールガスを流した状態では、注入管内でのガスの巻込みがさらに増加するために、十分なシールガス浮上効果が得られないと言える。シールガスを流した状態において注入管内でガスを浮上させる場合や注入流量を大きくする場合には、さらに太径の注入管を用いる必要があると考えられ、鋳造歩留りの悪化や注入管の設置場所の不足が予測される。   However, in the method of increasing the diameter of the injection tube described in Patent Document 1, the inside of the mold for casting the ingot is not produced even if the seal body prevents the inflow of the atmosphere without flowing into the injection tube of the seal gas. It is not possible to prevent the surface gas from flowing into the surface and eliminate any surface defects. On the other hand, when there is an air entrainment without a sealing body, more surface skin than when there is a sealing body A defect has occurred. From this, it can be said that when the seal gas is flowed, the entrainment of the gas in the injection pipe further increases, so that a sufficient seal gas floating effect cannot be obtained. When the gas is floated in the injection tube with the seal gas flowing or when the injection flow rate is increased, it is considered necessary to use a larger diameter injection tube, which deteriorates the casting yield and places the injection tube. The shortage is predicted.

特許文献２に記載の注入管とその直近の下注造塊用鋳型を結ぶ湯道の間にガス抜き管を立てる方法では、注入管から分岐した湯道毎にガス抜き管を立てる必要があり、注入管から分岐した湯道が多い程、鋳造歩留りが悪化し、ガス抜き管の設置場所の不足も予測される。また、鋳造歩留りの悪化を小さくするためにガス抜き管を細くすると、シールガスを多量に巻込んだ場合には、ガス抜き管の上端から気泡と共に溶鋼が吹き上がるおそれがある。   In the method of standing a degassing pipe between the injection pipe described in Patent Document 2 and the runner connecting the immediate casting ingot casting mold, it is necessary to set up the degassing pipe for every runway branched from the injection pipe. The more runners branched from the injection pipe, the worse the casting yield, and the shortage of the location for installing the gas vent pipe is also predicted. Further, if the degassing pipe is made thin in order to reduce the deterioration of the casting yield, molten steel may be blown up along with bubbles from the upper end of the degassing pipe when a large amount of sealing gas is wound.

特開２０００−２３３２６０号公報JP 2000-233260 A 特開２００２−２１９５５６号公報JP 2002-219556 A

本発明が解決しようとする課題は、シールガスを使用する溶鋼の下注造塊方法において、１本の湯道から複数の下注造塊用鋳型への溶鋼の流入を複数の下注造塊用鋳型へ順次分岐する形態で鋳造する場合に、湯道を流れる溶鋼を旋回流とすることで注入管内で巻込んだシールガスの気泡を湯道内の中心部に集め、下注造塊用鋳型内への流入を複数の下注造塊用鋳型に分散させることで、下注造塊用鋳型内の溶鋼の表面の揺らぎを軽減し、鋼塊の表面肌の悪化や下注造塊用鋳型内で溶鋼の表面を覆っている被覆材の巻込みを防止できる方法を提供することである。   The problem to be solved by the present invention is to provide a plurality of sub-casting ingots for inflow of molten steel from one runway to a plurality of molds for sub-casting ingots. When casting in the form of branching to the casting mold, the molten steel flowing in the runner is turned into a swirling flow to collect the sealing gas bubbles in the injection pipe at the center of the runner, and the mold for the ingot casting Dispersing the inflow into multiple molds for ingot casting ingots reduces fluctuations in the surface of the molten steel in the ingot casting molds, worsens the surface of the steel ingot, and molds for ingot casting It is providing the method of preventing the envelopment of the coating | covering material which has covered the surface of the molten steel in the inside.

上記の課題を達成するための本発明の手段は、請求項１の発明では、取鍋から注入管を経て下注造塊用の湯道に溶鋼を流す際に、垂直に配設した注入管の上部入口から溶鋼を流して落下させる。この場合、この注入管の下端部に段差部を設け、該段差部において、溶鋼の流れを垂直落下から切り替えて段差部の終端部に向け、さらにこの段差部の終端部に設けた下向きの下垂管部で溶鋼の流れを下垂管部の方向の下部に向けるものとし、さらに段差部の底面の延長線より低位かつ直近に位置する段差部の終端部の下垂管部の側壁に配設の出口から水平方向の湯道に溶鋼を流すことで、湯道において旋回流を発生させて下注造塊用鋳型への注湯方法である。従来の下注造塊用鋳型への湯道における溶鋼の流れは、湯道方向に向いた水平流であったが、本発明の請求項１の手段では、湯道に旋回流を発生させてシールガスの気泡を湯道の中心部に位置させた状態で下注造塊用鋳型へ下注ぎして鋼塊表面肌を改善する注湯方法である。   According to the first aspect of the present invention, the injection pipe arranged vertically when flowing the molten steel from the ladle through the injection pipe to the runner for the ingot casting The molten steel is poured from the upper entrance of the steel and dropped. In this case, a step portion is provided at the lower end portion of the injection pipe, and the flow of the molten steel is switched from the vertical drop toward the end portion of the step portion at the step portion. The flow of the molten steel is directed to the lower part in the direction of the downpipe pipe part in the pipe part, and the outlet provided on the side wall of the downpipe pipe part at the end of the step part located lower and closest to the extension line of the bottom face of the step part This is a method for pouring molten steel into a horizontal runner to create a swirling flow in the runner and pouring it into a casting mold for ingot casting. The flow of molten steel in the runner to the casting mold for the conventional ingot casting was a horizontal flow facing the runner direction. However, in the means of claim 1 of the present invention, a swirl flow is generated in the runner. This is a pouring method in which the surface of the steel ingot is improved by pouring it into the casting mold for the pouring ingot in a state where the bubbles of the sealing gas are located at the center of the runner.

請求項２の発明では、段差部の終端部の下垂管部の側壁に配設の出口の位置を注入管の中心軸から水平方向に注入管の太さの１／２〜３倍ずらし、かつ、段差部の底面の延長線より出口の上端面を０〜３００ｍｍ下部に偏位させ、該出口から水平方向の湯道に溶鋼を流すことを特徴とする請求項１の手段の湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法である。   In the invention of claim 2, the position of the outlet provided on the side wall of the drop tube portion at the end of the step portion is shifted from the central axis of the injection tube in the horizontal direction by 1/2 to 3 times the thickness of the injection tube, and The upper end surface of the outlet is deviated from 0 to 300 mm below the extension line of the bottom surface of the stepped portion, and the molten steel is caused to flow from the outlet to the horizontal runner. This is a method of pouring a mold for undercast ingots that generates a flow to improve the surface of the steel ingot.

請求項３の発明では、注入管の下端部に設けた段差部を水平方向に配設して該段差部に溶鋼を流すことを特徴とする請求項２の手段の湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法である。   According to a third aspect of the present invention, a stepped portion provided at the lower end portion of the injection pipe is disposed in the horizontal direction, and molten steel is caused to flow through the stepped portion. It is a pouring method to the mold for undercast ingot which improves the surface skin of a steel ingot.

請求項４の発明では、注入管の下端部に設けた段差部を斜め下方向に配設して該段差部に溶鋼を流すことを特徴とする請求項２の手段の湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法である。   According to a fourth aspect of the present invention, the step portion provided at the lower end portion of the injection pipe is disposed obliquely downward and the molten steel is caused to flow through the step portion. This is a pouring method for a mold for ingot casting to improve the surface of the steel ingot.

本発明の上記方法の手段とする理由および原理について説明する。先ず、従来の下注造塊方法では、湯道内の溶鋼流は単なる水平流である。先ず取鍋から注入管へ溶鋼を流す際に、注入管の上部入口を取鍋の溶鋼開閉ゲート部に設けたフードで覆って、かつ、この入口をアルゴンや窒素などのシールガスで遮蔽する。しかし、このシールガスが取鍋からの溶鋼流に巻き込まれ、溶鋼と共に注入管へ入って出口から湯道に流され、溶鋼が水平流となって流れるとき、溶鋼中に含有のシールガスが気泡となって溶鋼から容易に分離し湯道の上面壁の部分に気泡となって浮上する。すなわち、注入管に多数の下注造塊用鋳型が直列に配設されている１本の水平な湯道の中で、注入管から直近の下注造塊用鋳型までの湯道内でシールガスは気泡となり、湯道の水平な上面壁部に溜まり、溜まった大部分の気泡が注入管に直近の下注造塊用鋳型へ巻き込まれて流入する。このために直近の下注造塊用鋳型内の溶鋼表面には、巻込まれたシールガスによる揺らぎが発生する結果、溶鋼表面の被覆材が溶鋼に巻き込まれる問題があった。   The reason and principle of the method of the present invention will be described. First, in the conventional ingot casting method, the molten steel flow in the runner is a mere horizontal flow. First, when flowing molten steel from the ladle to the pouring pipe, the upper inlet of the pouring pipe is covered with a hood provided at the molten steel opening / closing gate portion of the ladle, and this inlet is shielded with a sealing gas such as argon or nitrogen. However, when this seal gas is entrained in the molten steel flow from the ladle, enters the injection pipe together with the molten steel, flows from the outlet to the runner, and when the molten steel flows as a horizontal flow, the seal gas contained in the molten steel is bubbled It easily separates from the molten steel and rises as bubbles on the upper wall of the runway. That is, in one horizontal runner in which a large number of casting molds are arranged in series on the injection pipe, the sealing gas is formed in the runway from the injection pipe to the nearest casting mold. Becomes bubbles and accumulates on the horizontal upper surface wall of the runner, and most of the accumulated bubbles are drawn into the casting mold for the ingot and cast into the casting tube. For this reason, there has been a problem that the coating material on the surface of the molten steel is caught in the molten steel on the surface of the molten steel in the casting mold for the last ingot.

しかしながら、本発明の手段では、注入管の下端部に段差部を設け、この段差部の終端部に下垂管部を設け、この段差部の底面の延長線より低位、かつ、直近に位置する段差部の終端部の下垂管部を形成する側壁に出口を配設することにより、段差部の底面の延長線よりも湯道への出口の上端面を下方に位置するようにずらし、さらに、この出口の位置を注入管の縦方向の中心軸の位置から水平方向にずらすことで、注入管を流れる溶鋼は出口から水平に延びる湯道に旋回流となって流入することとなる。このように溶鋼が旋回流となって湯道を流入することで、湯道を流れる溶鋼に遠心力が作用する。さらに、この旋回流となった溶鋼は含有しているシールガスの気泡に比して比重が大きいので、遠心力が作用した溶鋼は湯道の周壁部に拡大する。一方、シールガスの気泡は溶鋼に比して比重が小さいので湯道の中心部に集まる力が気泡に働く。この湯道の中心部に集まろうとするシールガスの気泡の力の方が湯道内で浮力により浮上分離しようとする力よりも大きいので、湯道におけるシールガスの気泡が浮上分離する作用が妨げられる。この結果、溶鋼はシールガスの気泡を湯道の中心部に内在した状態のまま、下注造塊用鋳型に順次注入されて行く。そこで、気泡を湯道の中心部に有して下注造塊用鋳型に流入する溶鋼は、注入管から直近にある下注造塊用鋳型のみならず最も遠い位置にある下注造塊用鋳型にも気泡が均等に分散されて下注ぎされる。このようにシールガスの気泡は分散されて下注造塊用鋳型に流入されるので、各下注造塊用鋳型に流入されるシールガスの気泡の量は略均一となる結果、１本の下注造塊用鋳型当たりの気泡の量は少なくなる。そこで、下注造塊用鋳型内を上昇する湯面は静かに上昇して気泡により揺らぐことがなくなり、下注造塊用鋳型内の溶鋼表面の被覆材は溶鋼中に巻き込まれることがなくなる。   However, in the means of the present invention, a step portion is provided at the lower end portion of the injection tube, a drop tube portion is provided at the end portion of the step portion, and the step located lower and closest to the extension line of the bottom surface of the step portion. By disposing the outlet on the side wall that forms the drooping pipe portion at the terminal end of the section, the upper end surface of the outlet to the runner is shifted downward from the extension line of the bottom surface of the stepped portion, and this By shifting the position of the outlet in the horizontal direction from the position of the longitudinal central axis of the injection pipe, the molten steel flowing through the injection pipe flows into the runner extending horizontally from the outlet as a swirling flow. Thus, centrifugal force acts on the molten steel flowing in the runner as the molten steel turns into a swirling flow and flows into the runner. Further, the molten steel that has turned into a swirling flow has a specific gravity greater than that of the contained sealing gas bubbles, so that the molten steel on which the centrifugal force has acted expands to the peripheral wall portion of the runner. On the other hand, since the bubbles of the seal gas have a smaller specific gravity than the molten steel, the force gathered at the center of the runner acts on the bubbles. Since the force of the bubbles of the seal gas trying to collect in the center of the runway is greater than the force of floating and separating in the runway due to buoyancy, the action of the seal gas bubbles in the runway floating and separating is hindered. It is done. As a result, the molten steel is sequentially injected into the casting mold for the ingot casting in a state where the bubbles of the sealing gas are present in the center of the runner. Therefore, the molten steel that has air bubbles in the center of the runner and flows into the casting mold for casting is used not only for casting casting molds closest to the injection pipe but also for casting castings that are farthest from the casting pipe. Bubbles are evenly dispersed in the mold and poured down. As described above, since the bubbles of the seal gas are dispersed and flow into the casting mold for the lower casting ingot, the amount of the bubbles of the sealing gas flowing into each casting mold for the lower casting ingot is substantially uniform. The amount of air bubbles per lower casting ingot mold is reduced. Therefore, the molten metal surface rising in the casting for ingot casting is gently raised and does not fluctuate due to bubbles, and the coating material on the surface of the molten steel in the casting for casting ingot is not caught in the molten steel.

本発明は上記の手段とすることで、注入管の下端部の段差部の下部から水平な湯道に入った溶鋼は旋回流とされているので、湯道内の溶鋼中に内在するシールガスの気泡は遠心力の作用で、比重の小さいシールガスが旋回流の中心部になって各下注造塊用鋳型に均等に分散されて搬入され、下注ぎされる。この結果、注入管との遠近に関係なく、１本の下注造塊用鋳型当たりに溶鋼と共に下注ぎされるシールガスの気泡の量は平均化される結果、少なくなるので、下注造塊用鋳型内において溶鋼の湯面が揺らぐことなく平穏に上昇し、吹き上がることがない。そこで、得られた鋼塊の表面肌は荒れることなく、さらに、下注造塊用鋳型内の湯面に被覆材を巻き込むこともないので、表面欠陥の無い清浄化された高品質の鋼塊が得られることとなるなど、本願の方法は従来にない優れた注湯方法である。   Since the present invention is the above-mentioned means, the molten steel that has entered the horizontal runner from the lower part of the step portion at the lower end of the injection pipe is swirling, so that the sealing gas contained in the molten steel in the runner The bubbles are caused by centrifugal force, and the seal gas having a small specific gravity becomes the central part of the swirl flow, is uniformly distributed and carried into the respective casting molds for lower casting, and is poured downward. As a result, the amount of the seal gas bubbles to be poured together with the molten steel per one mold for casting ingots is reduced as a result of averaging regardless of the distance from the injection tube. In the casting mold, the molten steel surface rises calmly and does not blow up. Therefore, the surface skin of the obtained steel ingot is not roughened, and further, the coating material is not caught on the molten metal surface in the mold for ingot casting. Therefore, the method of the present application is an excellent pouring method that has never been obtained.

本発明の実施の形態について、図面を参照して説明する。図１に本発明の実施の形態の一例に用いる注入管１を示す模式的断面図で、図２に本発明の他の実施の形態に用いる注入管１ａを示す模式的断面図である。図３は本発明の実施の形態における注入管１から湯道７を通じて各下注造塊用鋳型１０へ均等に流入する溶鋼１１の旋回流１３およびシールガスの気泡１５の流入状態を示す模式的断面図である。図４は本発明の実施に不都合な注入管１ｂの例を示す模式的断面図である。図５は図４の不都合な注入管１ｂにより生じた湯道７における水平流１４およびシールガスの気泡１５の下注造塊用鋳型１０への流入状態を示す模式的断面図である。さらに図６は本発明の実施の形態の方法を適用した下注造塊用鋳型設備を示す模式的断面図である。すなわち、図６の（ａ）に、取鍋８から溶鋼１１を注入管１および湯道７を経て、湯道７に直列に配列した複数の下注造塊用鋳型１０に溶鋼１１を下注ぎ鋳造する際の取鍋８、注入管１、湯道７および複数の下注造塊用鋳型１０の配置を示す模式的側面図である。さらに図６の（ｂ）は図６の（ａ）の矢視Ｘ−Ｘで示す模式的平面図である。図７は従来の注入管を用いた造塊装置を示し、（ａ）は模式的側面図で、（ｂ）は（ａ）における注入管１、湯道７、下注造塊用鋳型１０を示す平面図である。さらに図７の（ｂ）は図７の（ａ）の矢視Ｘ−Ｘで示す模式的平面図である。図８は本発明の方法と従来例の鋼塊表面肌欠陥の調査結果を示すグラフである。   Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an injection tube 1 used in an example of an embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view showing an injection tube 1a used in another embodiment of the present invention. FIG. 3 is a schematic diagram showing the inflow state of the swirl flow 13 of the molten steel 11 and the seal gas bubbles 15 that flow evenly from the injection pipe 1 through the runner 7 to each of the castings 10 for ingot casting in the embodiment of the present invention. It is sectional drawing. FIG. 4 is a schematic cross-sectional view showing an example of an injection tube 1b that is inconvenient for the implementation of the present invention. FIG. 5 is a schematic cross-sectional view showing the horizontal flow 14 and the flow of the seal gas bubbles 15 in the runner 7 produced by the inconvenient injection pipe 1b of FIG. Further, FIG. 6 is a schematic cross-sectional view showing a casting casting ingot casting facility to which the method of the embodiment of the present invention is applied. 6 (a), the molten steel 11 is poured from the ladle 8 through the injection pipe 1 and the runner 7 into a plurality of casting ingot casting molds 10 arranged in series in the runner 7. It is a typical side view which shows arrangement | positioning of the ladle 8 at the time of casting, the injection pipe 1, the runner 7, and the some casting mold 10 for ingot casting. Further, FIG. 6B is a schematic plan view shown by an arrow XX in FIG. FIG. 7 shows an ingot forming apparatus using a conventional injection tube, (a) is a schematic side view, and (b) shows the injection tube 1, runner 7, and lower casting ingot mold 10 in (a). FIG. Further, FIG. 7B is a schematic plan view indicated by an arrow XX in FIG. FIG. 8 is a graph showing the results of investigating the surface defects of the steel ingot surface of the method of the present invention and the conventional example.

先ず、本願発明の第１の実施の形態に用いる設備について図１により説明する。この設備における注入管１は、その上端に溶鋼１１を取鍋８から流入する上部入口４を有し、この注入管１の下端部２には段差部３を有する。そして第１の実施の形態の方法では、この段差部３は水平方向の向きを有し、請求項３の手段となっている。さらに、この段差部３の終端部３ａには下垂管部５を有する。この下垂管部５は、段差部３の水平な底面３ｂの延長線の下部に形成されており、その下垂管部５の側壁のうち、その壁面が水平な段差部３の側壁と同一側の側壁５ａに、段差部３の方向と直角かつ水平方向に、図６に示すように、左右の出口６が配設されている。これらの左右の出口６から湯道７が水平方向に連接されており、溶鋼１１がこの左右の湯道７を経由して下注造塊用鋳型１０に注入される。なお、注入管１の段差部３の終端部３ａの下垂管部５の下端５ｂは出口６の下側の直近位置で閉じられている。   First, the equipment used in the first embodiment of the present invention will be described with reference to FIG. The injection pipe 1 in this facility has an upper inlet 4 through which the molten steel 11 flows from the ladle 8 at the upper end, and a step 3 at the lower end 2 of the injection pipe 1. And in the method of 1st Embodiment, this level | step-difference part 3 has the direction of a horizontal direction, and is the means of Claim 3. Further, a drop tube portion 5 is provided at the end portion 3 a of the step portion 3. The downpipe portion 5 is formed below the extension of the horizontal bottom surface 3 b of the step portion 3. Of the side walls of the droppipe portion 5, the wall surface is on the same side as the side wall of the horizontal step portion 3. As shown in FIG. 6, left and right outlets 6 are arranged on the side wall 5 a at right angles to the direction of the stepped portion 3 and in the horizontal direction. The runners 7 are connected in the horizontal direction from the left and right outlets 6, and the molten steel 11 is poured into the casting mold 10 for the lower casting ingot via the left and right runners 7. Note that the lower end 5 b of the drop tube portion 5 of the end portion 3 a of the step portion 3 of the injection tube 1 is closed at the nearest position below the outlet 6.

さらに、本発明の第１の実施の形態に用いる設備では、注入管１の下部に水平方向の段差部３を有する。この注入管１において、本願の請求項２の１実施の形態として、段差部３の終端部３ａに配設の下垂管部５の側壁５ａに開口の出口６は、出口６の中心が注入管１の中心軸から水平方向に注入管１の太さの１／２倍〜３倍の偏位幅３ｄの範囲で偏位して設けられている。さらに、湯道７の水平な上面壁７ａよりも０〜３００ｍｍ上側へ高くなった位置に偏位して段差部３の底面３ａの延長線が位置するように形成するものとして湯道７への出口６の位置を形成する。   Furthermore, the equipment used in the first embodiment of the present invention has a horizontal step 3 at the bottom of the injection tube 1. In this injection tube 1, as an embodiment of claim 2 of the present application, the outlet 6 opened on the side wall 5 a of the drop tube portion 5 disposed at the terminal end 3 a of the step portion 3 is the center of the outlet 6. 1 is displaced in the horizontal direction from the central axis of 1 within a range of a displacement width 3d that is 1/2 to 3 times the thickness of the injection tube 1. Further, the runway 7 is formed so that the extension line of the bottom surface 3a of the stepped portion 3 is positioned so as to be shifted to a position higher by 0 to 300 mm above the horizontal upper surface wall 7a of the runway 7. Form the position of the outlet 6.

本発明の第１の実施の形態の下注造塊用鋳型１０への注湯方法について説明する。先ず、精錬された溶鋼１１を取鍋８のフード９から垂直下向きの注入管１の上部入口４に注入して下方に落下させる。次いで、この注入管１の下端部２に設けた段差部３で、落下した溶鋼１１の流れを段差部３の終端部３ａに転回させる。さらに、段差部３の終端部３ａに配設の下向きの下垂管部５で、溶鋼１１の流れを下部に転回させ、段差部３の底面３ｂより低位で、かつ、底面３ｂの直近である下垂管部５の側壁５ａの位置に段差部３の方向と水平で直角な方向に向いて配設の出口６に転回させる。さらにこの出口６から水平に配設した湯道７に溶鋼１１を流すものとしている。このように注入管１の下端部２から段差部３に溶鋼１１の流れを方向転換し、さらに段差部３の終端部３ａで下垂管部５で再び方向転換して水平の向きとすることにより、下垂管部５に流入した溶鋼１１に図３に示す旋回流１３を付与する。この旋回流１３となった溶鋼１１を出口６から湯道７に流すことで、溶鋼１１は湯道７内を旋回流１３の状態で流れ、各下注造塊用鋳型１０の下部の鋳型入口１２から下注造塊用鋳型１０内に下注ぎされる。この第１の実施の形態における段差部３は請求項３の発明の手段における注入管１の下端部２で水平方向に配設されている。   A method for pouring the casting into the mold 10 for the ingot casting in the first embodiment of the present invention will be described. First, the refined molten steel 11 is poured from the hood 9 of the pan 8 into the upper inlet 4 of the vertically downward injection pipe 1 and dropped downward. Subsequently, the flow of the dropped molten steel 11 is turned to the terminal end portion 3 a of the step portion 3 by the step portion 3 provided at the lower end portion 2 of the injection pipe 1. Further, the downwardly descending pipe portion 5 disposed at the terminal end portion 3a of the stepped portion 3 turns the flow of the molten steel 11 downward so that the drooping is lower than the bottom surface 3b of the stepped portion 3 and close to the bottom surface 3b. The pipe 5 is turned to the outlet 6 disposed at the side wall 5a in the direction perpendicular to the direction of the stepped portion 3 in the horizontal direction. Further, the molten steel 11 flows from the outlet 6 to the runner 7 disposed horizontally. In this way, the direction of the flow of the molten steel 11 is changed from the lower end portion 2 of the injection tube 1 to the step portion 3, and the direction is again changed at the terminal portion 3 a of the step portion 3 by the downpipe tube portion 5 to be in the horizontal direction. The swirling flow 13 shown in FIG. 3 is applied to the molten steel 11 that has flowed into the downpipe section 5. By flowing the molten steel 11 that has become the swirl flow 13 from the outlet 6 to the runner 7, the molten steel 11 flows in the runner 7 in the swirl flow 13, and the lower mold inlet of each lower casting ingot mold 10. No. 12 is poured into the casting mold 10 for ingot casting. The step portion 3 in the first embodiment is disposed in the horizontal direction at the lower end portion 2 of the injection tube 1 in the means of the invention of claim 3.

ところで、本発明の請求項２の手段の方法では、湯道７への出口６の中心位置が注入管１の中心軸から偏位する水平方向の偏位幅３ｄの大きさが、注入管１の太さの１／２倍より小さいと、湯道７内で生じる旋回流１３は弱過ぎ十分な旋回流１３とならない。一方、偏位する水平方向の偏位幅３ｄの大きさが注入管１の太さの３倍より大きくなっても、湯道７内に生じる旋回流１３は３倍のものと変わらず、その強さは飽和する。したがって水平方向の偏位幅３ｄの大きさを注入管１の太さの３倍よりも大きくすると、その大きくした分だけ設置スペースが大きくなり、かつ、大きくなっても歩留りは向上しないので、大きさに対する歩留りは悪化するなどのデメリットとなる。そこで、出口６を下垂管部５の側壁５ａに配設する位置は、出口６における下垂管部５の中心軸の位置が注入管１の中心軸から水平方向に注入管１の太さの１／２倍〜３倍の範囲の偏位量３ｄで偏位した位置に配設するものとしている。さらに、段差部３の底面３ａの位置から０〜３００ｍｍ下がった位置に湯道７の上面壁７ａが位置するように湯道７への出口６の位置を定める理由は、段差部３の底面３ａの位置が出口６に続く湯道７の上面壁７ａの位置よりも低過ぎると、湯道７内に旋回流１３ができないこととなるからであり、一方、逆に段差部３の底面３ａの位置が出口６に続く湯道７の上面壁７ａの位置よりも高過ぎると、湯道７内にできる旋回流１３が弱すぎることとなるからである。   By the way, in the method of the means of claim 2 of the present invention, the size of the horizontal displacement width 3d at which the center position of the outlet 6 to the runner 7 is displaced from the central axis of the injection tube 1 is such that the injection tube 1 If it is smaller than ½ times the thickness, the swirl flow 13 generated in the runner 7 is too weak to be a sufficient swirl flow 13. On the other hand, even if the horizontal displacement width 3d to be displaced is larger than three times the thickness of the injection pipe 1, the swirling flow 13 generated in the runner 7 is not different from that of three times. The strength is saturated. Therefore, if the size of the horizontal deviation width 3d is larger than three times the thickness of the injection tube 1, the installation space will be increased by that amount, and the yield will not improve even if it is increased. This is a demerit such as a worsening of the yield. Therefore, the position where the outlet 6 is disposed on the side wall 5a of the drop tube portion 5 is such that the position of the central axis of the drop tube portion 5 at the outlet 6 is equal to the thickness of the injection tube 1 in the horizontal direction from the central axis of the injection tube 1. It is assumed that it is arranged at a position displaced by a displacement amount 3d in the range of / 2 to 3 times. Furthermore, the reason for determining the position of the outlet 6 to the runner 7 so that the upper wall 7a of the runner 7 is located at a position 0 to 300 mm lower than the position of the bottom face 3a of the step portion 3 is that the bottom face 3a of the step portion 3 If the position is too lower than the position of the upper surface wall 7a of the runner 7 leading to the outlet 6, the swirl flow 13 cannot be generated in the runner 7. On the other hand, the bottom surface 3a of the step 3 This is because if the position is too higher than the position of the upper surface wall 7a of the runner 7 following the outlet 6, the swirl flow 13 formed in the runner 7 will be too weak.

本願発明の第２の実施の形態に用いる設備である図２に示す注入管１ａについて説明する。本願発明の注入管１ａは、その下端部２ａの段差部３が斜め下方向に配設されており、その段差部３の終端部３ａに下向きの下垂管部５を有する。下垂管部５の側壁５ａのうち、その壁面が斜め下方向の段差部３の側壁と同一側の側壁５ａに、段差部３の張出し方向と直角かつ水平方向に、図６に示すように、左右の出口６が配設されている。第１の実施の形態の設備と同様に、これらの左右の出口６から湯道７が水平方向に連接されており、溶鋼１１がこの左右の湯道７を経由して下注造塊用鋳型１０に注入される。なお、注入管１ａの段差部３の終端部３ａの下垂管部５の下端５ｂは出口６の下側の直近位置で閉じられている。   An injection tube 1a shown in FIG. 2 which is equipment used in the second embodiment of the present invention will be described. The injection tube 1a of the present invention has a stepped portion 3 at the lower end portion 2a thereof disposed obliquely downward, and has a downwardly descending tube portion 5 at the terminal end portion 3a of the stepped portion 3. As shown in FIG. 6, of the side wall 5 a of the downpipe pipe portion 5, the wall surface is on the same side as the side wall of the stepped portion 3 in the obliquely downward direction, perpendicular to the protruding direction of the stepped portion 3 and horizontally. Left and right outlets 6 are provided. Similar to the equipment of the first embodiment, the runners 7 are connected in the horizontal direction from the left and right outlets 6, and the molten steel 11 passes through the left and right runners 7 and is used as a casting mold for lower casting. 10 is injected. In addition, the lower end 5b of the drooping pipe part 5 of the terminal part 3a of the step part 3 of the injection pipe 1a is closed at the nearest position below the outlet 6.

さらに、本発明の第２の実施の形態に用いる設備では、下部に斜め下方向の段差部３を有する注入管１ａにおいて、本願の請求項４の１実施の形態として、段差部３の終端部３ａに配設の下垂管部５の側壁５ａに開口の出口６は、出口６における下垂管部５の中心軸の位置が注入管１ａの中心軸から水平方向に注入管１ａの太さの１／２倍〜３倍の範囲の偏位量３ｄで偏位して設けられている。さらに、段差部３の底面３ｂの延長線３ｃより０〜３００ｍｍ下部に湯道７の水平な上面壁７ａを偏位させて配設し、この出口６から湯道７に溶鋼１１を流すものとしている。このように湯道７への出口６の位置を段差部３の底面３ｂの延長線３ｃより下方に配置することで、図３に示すように、湯道７に流入した溶鋼１１に旋回流１３が生じる。この場合、この旋回流１３により質量の大である溶鋼１１が遠心力により旋回流１３の周囲となり、注入管１ｂの上部入口４から溶鋼１１に巻き込まれたシールガスの気泡１５が旋回流１３の中心部に位置して湯道７を連接された各鋳型入口１２まで流れるので、注入管１ａの直近のみでなく遠い部分の鋳型入口１２の位置する下注造塊用鋳型１０にも略均一に溶鋼１１および巻き込まれたシールガスの気泡１５が分配されることとなるので、結果的に１本の下注造塊用鋳型１０当たりのシールガスの気泡１５の量は少なく、下注造塊用鋳型１０内の溶鋼上面に気泡による揺らぎを生じることなく、したがって、一連の造塊された鋼塊は均質な清浄な鋼となる。   Furthermore, in the equipment used for the second embodiment of the present invention, in the injection pipe 1a having the step portion 3 obliquely downward at the lower portion, as an embodiment of claim 4 of the present application, the terminal portion of the step portion 3 is used. 3a, the outlet 6 of the opening on the side wall 5a of the drop tube portion 5 has a position of the central axis of the drop tube portion 5 at the outlet 6 of the thickness of the injection tube 1a in the horizontal direction from the central axis of the injection tube 1a. It is displaced by a displacement amount 3d in a range of / 2 to 3 times. Furthermore, the horizontal upper surface wall 7a of the runner 7 is arranged to be deviated from 0 to 300 mm below the extension line 3c of the bottom surface 3b of the stepped portion 3, and the molten steel 11 flows from the outlet 6 to the runner 7. Yes. In this way, by arranging the position of the outlet 6 to the runner 7 below the extension line 3c of the bottom surface 3b of the stepped portion 3, as shown in FIG. Occurs. In this case, the swirling flow 13 causes the molten steel 11 having a large mass to be around the swirling flow 13 due to centrifugal force, and the bubbles 15 of the seal gas entrained in the molten steel 11 from the upper inlet 4 of the injection pipe 1 b become the swirling flow 13. Since it flows to each mold inlet 12 connected to the runner 7 at the center, it is substantially uniform not only in the immediate vicinity of the injection pipe 1a but also in the casting mold 10 for the lower casting ingot located in the far part of the mold inlet 12. Since the molten steel 11 and the entrained sealing gas bubbles 15 are distributed, the amount of the sealing gas bubbles 15 per one ingot casting ingot mold 10 is small, resulting in the infusion casting ingot. The upper surface of the molten steel in the mold 10 does not fluctuate due to bubbles, so that the series of ingots becomes a homogeneous clean steel.

これに対し、図４に示す注入管１ｂにおいて、段差部３の底面３ｂの延長線３ｃより上方に出口６および図５の湯道７の上面壁７ａが位置すると、図５に示すように、湯道７内に流入した溶鋼１１に旋回流１３ができないで水平流１４となるか、あるいは旋回流１３ができても弱い旋回流１３となる。このために注入管１ｂの上部入口４から溶鋼１１に巻き込まれたシールガスの気泡１５が湯道７内で容易に浮上分離して浮上気泡１６となり、湯道７内の注入管１ｂに近い湯道７の上面壁７ａの部分に溜まる。この結果、大部分のシールガスの気泡１５が注入管１ｂの直近の下注造塊用鋳型１０内に流入される。さらに、湯道７内に旋回流１３ができても、上記段落００２０のように、弱すぎる場合にも、湯道７内にシールガスの気泡１５が分離浮上して浮上気泡１６となり、注入管１ｂに直近の鋳型入口１２にシールガスの気泡１５が略流入してしまうこととなる。したがって、このシールガスの気泡１５が流入した下注造塊用鋳型１０では、下注造塊用鋳型１０内で溶鋼上面に気泡による揺らぎを生じ、被覆材を巻き込むこととなり、一方、注入管１ｂから遠い下注造塊用鋳型１０内にはシールガスの気泡１５が流入しないため、下注造塊用鋳型１０内で溶鋼上面に気泡による揺らぎを生じない。このように一連の下注造塊用鋳型１０で造塊した鋼塊の品質にバラツキを生じる。   On the other hand, in the injection tube 1b shown in FIG. 4, when the outlet 6 and the upper wall 7a of the runner 7 of FIG. 5 are positioned above the extension line 3c of the bottom surface 3b of the step portion 3, as shown in FIG. Even if the swirl flow 13 is generated, the swirl flow 13 is not generated in the molten steel 11 flowing into the runner 7, or the swirl flow 13 is weak. For this reason, the seal gas bubble 15 entrapped in the molten steel 11 from the upper inlet 4 of the injection pipe 1 b easily floats and separates in the runner 7 to form a floating bubble 16, and the hot water close to the injection pipe 1 b in the runner 7. It accumulates on the upper surface wall 7 a of the road 7. As a result, most of the bubbles 15 of the sealing gas flow into the lower casting ingot mold 10 in the immediate vicinity of the injection tube 1b. Further, even if the swirl flow 13 can be formed in the runner 7, even if it is too weak as in the above paragraph 0020, the bubble 15 of the seal gas separates and floats in the runner 7 to become the floating bubble 16, and the injection pipe The bubble 15 of the seal gas will almost flow into the mold inlet 12 closest to 1b. Therefore, in the lower casting ingot mold 10 into which the bubbles 15 of the sealing gas have flowed, fluctuations due to the bubbles are generated on the upper surface of the molten steel in the lower casting ingot mold 10 and the covering material is entrained. Since the bubble 15 of the sealing gas does not flow into the lower casting ingot mold 10 which is far from the lower casting ingot mold 10, fluctuations due to the bubbles do not occur on the upper surface of the molten steel in the lower casting ingot mold 10. In this way, the quality of the steel ingot formed by the series of the ingot casting mold 10 varies.

図１の模式図に示す注入管１の下端部２の水平な段差部３を有し、段差部３の終端部３ａに下垂管部５の側壁５ａに配設の出口６から溶鋼１１を流出して湯道７に旋回流１３を発生させた本発明の方法を用い、図６に示す下注造塊の形態において、ＪＩＳ Ｇ ４１０４のＳＣＲ４２０鋼の５ｔ鋼塊８本を下注造塊用鋳型１０により１０チャージ鋳造した。鋳造の際、シールガスにはアルゴンを用い、取鍋８のフード９から１Ｎｍ3 ／ｍｉｎの流量で吹き込んだ。下注造塊用鋳型１０内の溶鋼表面の揺らぎの目視調査と得られた鋼塊表面の調査を実施した。その結果、１０チャージを平均して表１に示す。 1 has a horizontal step portion 3 at the lower end portion 2 of the injection tube 1 shown in the schematic diagram of FIG. 1, and the molten steel 11 flows out from an outlet 6 disposed on the side wall 5a of the downpipe portion 5 to the end portion 3a of the step portion 3. Then, using the method of the present invention in which the swirling flow 13 is generated in the runner 7, in the form of the lower casting ingot shown in FIG. 6, eight 5t steel ingots of SCR 420 steel of JIS G 4104 are used for the lower casting ingot. Ten charge castings were performed using the mold 10. At the time of casting, argon was used as the sealing gas and was blown from the hood 9 of the ladle 8 at a flow rate of 1 Nm 3 / min. The visual inspection of the fluctuation of the molten steel surface in the casting 10 for the ingot casting and the surface of the obtained steel ingot were conducted. As a result, 10 charges are averaged and shown in Table 1.

図２の模式図に示す注入管１ａの下端部２の下部に傾斜した段差部３を有し、段差部３の終端部３ａに下垂管部５の側壁５ａに配設の出口６から溶鋼１１を流出して湯道７に旋回流１３を発生させた本発明の方法を用い、図４に示す下注造塊の形態において、ＪＩＳ Ｇ ４１０４のＳＣＲ４２０鋼の５ｔ鋼塊８本を下注造塊用鋳型１０により１０チャージ鋳造した。鋳造の際、シールガスにはアルゴンを用い、取鍋８のフード９から１Ｎｍ3 ／ｍｉｎの流量で吹き込んだ。下注造塊用鋳型１０内の溶鋼表面の揺らぎの目視調査と得られた鋼塊表面の調査を実施した。その結果、１０チャージを平均して表１に示す。 2 has a stepped portion 3 inclined at the lower portion of the lower end portion 2 of the injection tube 1a shown in the schematic view of FIG. 2, and a molten steel 11 from an outlet 6 disposed on the side wall 5a of the downpipe tube portion 5 at the end portion 3a of the stepped portion 3. 4 and using the method of the present invention in which the swirling flow 13 is generated in the runner 7, in the form of the lower casting ingot shown in FIG. 4, eight 5t steel ingots of SCR 420 steel of JIS G 4104 are prepared by lower casting. Ten charge castings were performed using the lump mold 10. At the time of casting, argon was used as the sealing gas and was blown from the hood 9 of the ladle 8 at a flow rate of 1 Nm 3 / min. The visual inspection of the fluctuation of the molten steel surface in the casting 10 for the ingot casting and the surface of the obtained steel ingot were conducted. As a result, 10 charges are averaged and shown in Table 1.

比較例として、図７に示す従来の段差部を有しない注入管１による下注造塊の形態において、ＪＩＳ Ｇ ４１０４のＳＣＲ４２０鋼の５ｔ鋼塊８本を下注造塊用鋳型１０により１０チャージ鋳造した。上記の実施例１と同様に、鋳造の際、シールガスにはアルゴンを用い、取鍋８のフード９から１Ｎｍ3 ／ｍｉｎの流量で吹き込んだ。下注造塊用鋳型１０内の溶鋼表面の揺らぎの目視調査と得られた鋼塊表面の調査を実施した。その結果、１０チャージを平均して表１に示す。 As a comparative example, in the form of the lower casting ingot by the injection pipe 1 having no conventional stepped portion shown in FIG. 7, eight SCR 420 steel 5t steel ingots of JIS G 4104 are charged by the casting 10 for the lower casting ingot. Casted. In the same manner as in Example 1 above, argon was used as the sealing gas during casting, and the hood 9 in the ladle 8 was blown at a flow rate of 1 Nm 3 / min. The visual inspection of the fluctuation of the molten steel surface in the casting 10 for the ingot casting and the surface of the obtained steel ingot were conducted. As a result, 10 charges are averaged and shown in Table 1.

Figure 0005025312
Figure 0005025312

本発明の実施例１および実施例２の各方法では、注入管１および注入管１ａの各左右の４本ずつの下注造塊用鋳型１０ａ〜１０ｄと下注造塊用鋳型１０ａ’〜１０ｄ’において、表１に示すように、下注造塊用鋳型１０内の溶鋼表面の揺らぎは、下注造塊用鋳型１０ａ、１０ｂ、１０ａ’、１０ｂ’の４本は小さく、図８に示すように、得られた鋼塊表面肌欠陥指数は共に０．２未満であり、他の下注造塊用鋳型１０ｃ、１０ｄ、１０ｃ’〜１０ｄ’の４本は、表１に示すように、揺らぎは無く、図８に示すように、得られた鋼塊表面肌欠陥指数は共に０であった。このように本願発明の方法では、下注造塊用鋳型１０内に揺らぎがあっても小さく、鋼塊の表面肌欠陥も僅かで実質的に影響のないもので、いずれの下注造塊用鋳型１０による鋼塊も実用上問題のないものであった。   In each method of Example 1 and Example 2 of the present invention, four casting molds 10a to 10d and 4 casting molds 10a 'to 10d for each of the injection pipe 1 and the injection pipe 1a are provided. In FIG. 8, as shown in Table 1, the fluctuations of the surface of the molten steel in the casting for ingot casting 10 are small for the four casting casting molds 10a, 10b, 10a ′, 10b ′, and are shown in FIG. Thus, the obtained steel ingot surface skin defect index is both less than 0.2, and the other four casting molds 10c, 10d, 10c ′ to 10d ′ are as shown in Table 1. There was no fluctuation, and the obtained steel ingot surface skin defect index was 0 as shown in FIG. Thus, in the method of the present invention, even if there is a fluctuation in the mold 10 for the ingot casting, the surface defect of the steel ingot is slight and has no substantial effect, The steel ingot by the mold 10 was also practically unproblematic.

これに対し、従来の直管のみからなる注入管を用いた図７に示す装置では、注入管１の各左右の４本ずつの下注造塊用鋳型１０ａ〜１０ｄと下注造塊用鋳型１０ａ’〜１０ｄ’において、表１に示すように、下注造塊用鋳型１０内の溶鋼表面の揺らぎは左右の直近の下注造塊用鋳型１０ａ、１０ａ’の２本で大であり、図８に示すように、得られた鋼塊表面肌欠陥指数は共に１であった。その他の下注造塊用鋳型１０ｂ〜１０ｄおよび下注造塊用鋳型１０ｂ’〜１０ｄ’の計６本では、表１に示すように、揺らぎは無く、図８に示すように、得られた鋼塊表面肌欠陥指数は共に０であった。このように従来の注入管１では、注入管１の直近の左右の下注造塊用鋳型１０による鋼塊は、鋼塊表面肌の欠陥が大きく、このままでは使用にたえないもので、歩留りが悪かった。   On the other hand, in the apparatus shown in FIG. 7 using the conventional injection pipe consisting of only a straight pipe, the left and right ingot casting molds 10a to 10d and the lower casting ingot casting mold of each of the injection pipe 1 are provided. In 10a ′ to 10d ′, as shown in Table 1, the fluctuation of the molten steel surface in the casting ingot casting mold 10 is large in the two right and left casting casting molds 10a and 10a ′. As shown in FIG. 8, the obtained steel ingot surface skin defect index was 1. In the other 6 pieces of the ingot casting molds 10b to 10d and the casting ingot casting molds 10b ′ to 10d ′ in total, there was no fluctuation as shown in Table 1, and as shown in FIG. The steel ingot surface skin defect index was both 0. Thus, in the conventional injection tube 1, the steel ingot by the left and right ingot casting molds 10 immediately adjacent to the injection tube 1 has a large defect on the surface of the steel ingot and cannot be used as it is. Was bad.

本発明方法に用いる一形態の注入管の模式的断面図である。It is typical sectional drawing of the injection tube of one form used for a method of the present invention. 本発明方法に用いる他の形態の注入管の模式的断面図である。It is typical sectional drawing of the injection tube of the other form used for the method of this invention. 本発明の実施の形態における注入管から湯道を通じて各下注造塊用鋳型へ均等に流入する溶鋼の旋回流およびシールガスの気泡の流入状態を示す模式的断面図である。It is typical sectional drawing which shows the inflow state of the swirling flow of the molten steel and the bubble of seal gas which equally flow in into each casting mold for ingot casting from the injection pipe through the runner in the embodiment of the present invention. 本発明の実施に不都合な注入管の例を示す模式的断面図である。It is typical sectional drawing which shows the example of the injection tube which is inconvenient to implementation of this invention. 図４の不都合な注入管により生じた湯道における水平流およびシールガスの気泡の下注造塊用鋳型への流入状態を示す模式的断面図である。FIG. 5 is a schematic cross-sectional view showing a horizontal flow in a runner caused by the inconvenient injection pipe of FIG. 4 and a state of inflow of seal gas bubbles into a sub-ingot casting mold. 本発明の実施の形態の方法を適用した下注造塊用鋳型設備を示す模式的断面図である。It is typical sectional drawing which shows the casting equipment for lower casting ingots to which the method of embodiment of this invention is applied. 従来の注入管を用いた造塊装置を示し、（ａ）は模式的側面図で、（ｂ）は（ａ）における注入管、湯道、下注造塊用鋳型を示す平面図である。The agglomeration apparatus using the conventional injection | pouring pipe | tube is shown, (a) is a typical side view, (b) is a top view which shows the injection | pouring pipe | tube in the (a), a runner, and the casting mold for ingot casting. 本発明の方法と従来例の鋼塊表面肌欠陥の調査結果を示すグラフである。It is a graph which shows the investigation result of the steel ingot surface skin defect of the method of this invention, and a prior art example.

符号の説明Explanation of symbols

１ 注入管
１ａ 注入管
１ｂ 注入管
２ 下端部
３ 段差部
３ａ 終端部
３ｂ 底面
３ｃ 延長線
３ｄ 偏位幅
４ 上部入口
５ 下垂管部
５ａ 側壁
５ｂ 下端
６ 出口
７ 湯道
７ａ 上面壁
８ 取鍋
９ フード
１０ 下注造塊用鋳型
１１ 溶鋼
１２ 鋳型入口
１３ 旋回流
１４ 水平流
１５ シールガスの気泡
１６ 浮上気泡 DESCRIPTION OF SYMBOLS 1 Injection pipe 1a Injection pipe 1b Injection pipe 2 Lower end part 3 Step part 3a Termination part 3b Bottom face 3c Extension line 3d Deflection width 4 Upper inlet 5 Drop pipe part 5a Side wall 5b Lower end 6 Outlet 7 Runway 7a Upper surface wall 8 Ladle 9 Hood 10 Mold for casting ingot 11 Molten steel 12 Mold inlet 13 Swirling flow 14 Horizontal flow 15 Seal gas bubbles 16 Floating bubbles

Claims (4)

取鍋から注入管を経て下注造塊用の湯道に溶鋼を流す際に、垂直に配設した注入管の上部入口から溶鋼を注入して落下させ、該注入管の下端部に設けた段差部で溶鋼の流れを変更して段差部の終端部に向け、さらに段差部の終端部に設けた下垂管部で溶鋼の流れを終端部から下部に向け、段差部の底面の延長線より低位かつ直近に位置する段差部の終端部の下垂管部の側壁に配設の出口から水平方向の湯道に溶鋼を流すことを特徴とする湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法。 When flowing the molten steel from the ladle through the injection pipe to the runway for lower casting, the molten steel was injected and dropped from the upper inlet of the injection pipe arranged vertically, and provided at the lower end of the injection pipe. Change the flow of the molten steel at the stepped portion toward the terminal end of the stepped portion, and further direct the molten steel flow from the terminal end to the lower portion at the dropping tube provided at the terminal end of the stepped portion. The surface of the steel ingot surface by generating a swirling flow in the runway characterized by flowing molten steel from the outlet disposed on the side wall of the drop pipe part at the end of the stepped portion located at the lower and nearest position to the horizontal runway Method of pouring into casting molds for lower casting ingots. 段差部の終端部の下垂管部の側壁に配設の出口の位置を注入管の中心軸から水平方向に注入管の太さの１／２〜３倍ずらし、かつ、段差部の底面の延長線より出口の上端面を０〜３００ｍｍ下部に偏位させ、該出口から水平方向の湯道に溶鋼を流すことを特徴とする請求項１に記載の湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法。 The position of the outlet disposed on the side wall of the drop tube portion at the end of the step portion is shifted from the central axis of the injection tube in the horizontal direction by 1/2 to 3 times the thickness of the injection tube, and the bottom surface of the step portion is extended. 2. The steel ingot by generating a swirling flow in the runner according to claim 1, wherein the upper end surface of the exit is deviated from 0 to 300 mm below the wire and the molten steel is caused to flow from the exit to the horizontal runner. A pouring method for casting molds for lower casting to improve the surface skin. 注入管の下端部に設けた段差部を水平方向に配設して該段差部に溶鋼を流すことを特徴とする請求項２に記載の湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法。 3. A stepped portion provided at a lower end portion of an injection pipe is disposed in a horizontal direction so that molten steel flows through the stepped portion, and a swirling flow is generated in the runner to create a steel ingot surface skin. An improved method of pouring into casting molds for ingot casting. 注入管の下端部に設けた段差部を斜め下方向に配設して該段差部に溶鋼を流すことを特徴とする請求項２に記載の湯道に旋回流を発生させて鋼塊表面肌を改善する下注造塊用鋳型への注湯方法。 3. A step surface provided on a lower end portion of the injection pipe is disposed obliquely downward to allow molten steel to flow through the step portion. Method of pouring into casting molds for lower casting ingots.
JP2007101580A 2007-04-09 2007-04-09 Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner Expired - Fee Related JP5025312B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007101580A JP5025312B2 (en) 2007-04-09 2007-04-09 Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007101580A JP5025312B2 (en) 2007-04-09 2007-04-09 Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner

Publications (2)

Publication Number Publication Date
JP2008254058A JP2008254058A (en) 2008-10-23
JP5025312B2 true JP5025312B2 (en) 2012-09-12

Family

ID=39978180

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007101580A Expired - Fee Related JP5025312B2 (en) 2007-04-09 2007-04-09 Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner

Country Status (1)

Country Link
JP (1) JP5025312B2 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103949625B (en) * 2014-05-05 2017-11-14 江苏兴达高温合金科技有限公司 Molten steel current divider support

Also Published As

Publication number Publication date
JP2008254058A (en) 2008-10-23

Similar Documents

Publication Publication Date Title
US7559353B2 (en) Distributor for use in a method of casting hot metal
RU2450890C2 (en) Method and device for teeming nonferrous metal melt, particularly, copper or copper alloy melts
TWI379719B (en)
JP5516235B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP5025312B2 (en) Method of pouring into casting mold for ingot casting to improve the surface of steel ingot by generating swirling flow in runner
JP6454205B2 (en) Tundish for continuous casting and continuous casting method using the tundish
JP5831124B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP5556465B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP2008264816A (en) Method of pouring molten steel into bottom-pouring ingot making mold for improving steel ingot surface texture by generating swirl flow in runner
JP6491039B2 (en) Bottom pouring method
JP5751078B2 (en) Manufacturing method of high cleanliness steel slab by continuous casting
JP7070024B2 (en) Tandish
JP4542631B2 (en) Method and apparatus for manufacturing slabs
JP2008254028A (en) Tundish for continuous casting
JP4884261B2 (en) Injection tube for sub-ingot casting
KR20100035821A (en) Tundish
JP4998705B2 (en) Steel continuous casting method
JP6454206B2 (en) Tundish for continuous casting and continuous casting method using the tundish
JP6668568B2 (en) Tundish for continuous casting and continuous casting method using the tundish
US20050022961A1 (en) Casting system and method for pouring nonferrous metal molten masses
JP5450205B2 (en) Pouring nozzle
JP5794969B2 (en) Continuous casting method
JP5239554B2 (en) Immersion nozzle for continuous casting of slabs
JP7269480B2 (en) Continuous casting method
JP6668567B2 (en) Tundish for continuous casting and continuous casting method using the tundish

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20100210

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20110115

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: 20120619

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120619

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150629

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Free format text: JAPANESE INTERMEDIATE CODE: R150

LAPS Cancellation because of no payment of annual fees