JP2718097B2 - Vacuum cleaning method for molten metal using two-tiered container - Google Patents
Vacuum cleaning method for molten metal using two-tiered containerInfo
- Publication number
- JP2718097B2 JP2718097B2 JP25080888A JP25080888A JP2718097B2 JP 2718097 B2 JP2718097 B2 JP 2718097B2 JP 25080888 A JP25080888 A JP 25080888A JP 25080888 A JP25080888 A JP 25080888A JP 2718097 B2 JP2718097 B2 JP 2718097B2
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- molten metal
- vessel
- container
- gas
- pressure
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- Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、二段重ね容器を用いて溶融金属中に浮遊
する介在物を除去する溶融金属の減圧清浄化方法に関す
る。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying molten metal under reduced pressure by using a two-tiered container to remove inclusions floating in the molten metal.
溶融金属中に浮遊する介在物（例えば溶鋼中のアルミ
ナ系介在物）は、製品品質欠陥の原因となるため、その
低減・除去方法が種々提案されている。Inclusions floating in the molten metal (for example, alumina-based inclusions in molten steel) cause defects in product quality, and various methods for reducing and removing the inclusions have been proposed.
本発明者等は、高級材製造を目的とした場合溶鋼中の
トータル酸素量は15ppm以下に抑える必要があるとの要
請に鑑み、次のような提案を行なつた。即ち、加圧状態
にした溶融金属を、それに可溶なガスでバブリングして
該溶融金属中にガスを溶解せしめ、その後急速に減圧し
て溶融金属中に微細ガス気泡を発生させるというもので
ある。この方法によれば溶融金属中の通常の介在物は最
初のバブリングでそのガス気泡にトラツプされ浮上せし
められることになる。他方、このバブリングは加圧した
溶融金属に対して行なわれるため、バブリングガスが多
量に溶融金属中に溶け込むことになる。その後の急速な
減圧で、溶融金属中に溶け込んでいたガスが微細なガス
気泡となつて溶融金属全域から発生する。この時、微細
な介在物は該ガス気泡にトラツプされて浮上する。The present inventors have made the following proposals in view of the request that the total oxygen content in molten steel must be suppressed to 15 ppm or less for the purpose of producing high-grade materials. That is, the molten metal in a pressurized state is bubbled with a gas soluble in the molten metal to dissolve the gas in the molten metal, and then the pressure is rapidly reduced to generate fine gas bubbles in the molten metal. . According to this method, ordinary inclusions in the molten metal are trapped by the gas bubbles in the first bubbling and are caused to float. On the other hand, since the bubbling is performed on the pressurized molten metal, a large amount of the bubbling gas dissolves into the molten metal. Then, by rapid decompression, the gas dissolved in the molten metal is generated as fine gas bubbles from all over the molten metal. At this time, the fine inclusions are trapped by the gas bubbles and float.
このように溶融金属中の介在物を除去するには、極め
て効率の良い優れた方法ではあるが、減圧後の放置時間
が短い場合は、溶融金属中に前記バブリングガスが多量
に溶け残ることになるため、当該処理終了後更に脱ガス
を行なう必要があつた。In order to remove inclusions in the molten metal in this way, it is an extremely efficient and excellent method.However, if the leaving time after decompression is short, a large amount of the bubbling gas remains dissolved in the molten metal. Therefore, it is necessary to further degas after the completion of the processing.
そこで本発明者等は、上記方法のうちバブリングガス
が溶け残る原因となつていた、バブリング時の溶融金属
の加圧処理を止め、大気圧もしくはそれ以下の状態で該
バブリングを行ない、その後に減圧処理を行なう新たな
溶融金属の清浄化方法を提案した。この改良型の方法で
は減圧処理によつて微細ガス気泡が発生せしめられるだ
けでなく、溶融金属中の脱ガスも一緒に行なわれること
になる。Therefore, the present inventors stopped the pressure treatment of the molten metal at the time of bubbling, which caused the bubbling gas to remain undissolved in the above method, performed the bubbling at atmospheric pressure or lower, and then depressurized. A new cleaning method of molten metal for processing is proposed. In this improved method, not only fine gas bubbles are generated by the decompression treatment, but also degassing of the molten metal is performed at the same time.
このように溶融金属中の介在物を除去するためには、
上記の改良型の方法は極めて効率の良い優れた方法では
あるが、その実施に当つては第３図に示すような二つの
容器（100）（101）が用いられていた。即ち、容器（10
0）内に溶融金属（３）を入れた上で内部雰囲気をArガ
スに置換せしめると共に、該容器（100）内の圧力調整
を行なつて大気圧もしくはそれ以下に保ち、更に容器
（100）底部からArガス（バブリング用ガス）と溶融金
属（３）に可溶なガス（例えばH2ガス）との混合ガスを
バブリングする。そして、この容器（100）内のバブリ
ングを止め、ストツパ（200）を開放することで溶融金
属（３）を隣りの容器（101）に移す。その後該容器（1
01）を減圧容器として用い、調圧弁（101a）によつて容
器（101）の内部を急速に減圧せしめる。すると、微細
ガス気泡が多量に発生するため、これ（或いはバブリン
グ時のガス気泡）にトラツプされて浮上してきた介在物
を除去する。この時急速な減圧によつて溶融金属（３）
中の脱ガスも同時に行なわれることになる。Thus, in order to remove inclusions in the molten metal,
Although the above-mentioned improved method is a very efficient and excellent method, two containers (100) and (101) as shown in FIG. 3 were used in carrying out the method. That is, the container (10
After the molten metal (3) is placed in the container (0), the internal atmosphere is replaced with Ar gas, and the pressure in the container (100) is adjusted to atmospheric pressure or lower by adjusting the pressure in the container (100). A mixed gas of Ar gas (gas for bubbling) and gas (for example, H 2 gas) soluble in the molten metal (3) is bubbled from the bottom. Then, the bubbling in the container (100) is stopped, and the molten metal (3) is transferred to the adjacent container (101) by opening the stopper (200). Then the container (1
01) is used as a pressure reducing container, and the pressure inside the container (101) is rapidly reduced by the pressure regulating valve (101a). Then, since a large amount of fine gas bubbles are generated, inclusions trapped by the gas bubbles (or gas bubbles at the time of bubbling) and floated are removed. At this time, molten metal (3)
The degassing will be performed at the same time.
上記装置に用いられるストツパ（200）は、窒化ホウ
素やジルコニア系又はアルミナ系の耐火物が用いられ、
一回の実施で使用不能になる。そのため、実施毎に該ス
トツパ（200）の交換が必要となり、メンテナンスに多
くの時間と手間が掛かる。又溶融金属（３）が滲出てス
トツパ（200）を開口に溶着せしめてしまうということ
もあり、該ストツパ（200）の開放が不可能になるとい
う事故が起きることも多い。The stopper (200) used in the above apparatus is made of boron nitride, zirconia-based or alumina-based refractories,
It becomes unusable after one execution. Therefore, it is necessary to replace the stopper (200) every time the operation is performed, and much time and labor are required for maintenance. In addition, the molten metal (3) may ooze out and cause the stopper (200) to be welded to the opening, which often causes an accident that the stopper (200) cannot be opened.
本発明はこのような問題に鑑み創案されたもので、上
記改良型の方法を実際に実施するに当り、これらの問題
が発生することのない最適な実施方法を提供せんとする
ものである。The present invention has been made in view of such a problem, and an object of the present invention is to provide an optimum method of implementing the improved method without causing these problems.
そのため本発明法は、第１図に示されるように密閉容
器（1a）（1b）を上下二段に重ねてこれらの間を細管
（２）でつないだ処理設備を用いて行なわれ、次のよう
に処理される。Therefore, as shown in FIG. 1, the method of the present invention is carried out using processing equipment in which closed containers (1a) and (1b) are stacked in two stages, and these are connected by a thin tube (2). Is processed as follows.
即ち、上段の容器（1a）に溶融金属（３）を入れ該容
器（1a）内が大気圧もしくはそれ以下になるように圧力
調整する。この時下段の容器（1b）は、その中に溶融金
属（３）に可溶なガスを満たし、そこから細管（２）を
介して上段容器（1a）内の溶融金属（３）中に該ガスを
バブリングする。That is, the molten metal (3) is placed in the upper vessel (1a), and the pressure in the vessel (1a) is adjusted to atmospheric pressure or lower. At this time, the lower vessel (1b) is filled with a gas soluble in the molten metal (3), from which the gas is introduced into the molten metal (3) in the upper vessel (1a) via the thin tube (2). Bubble gas.
その後、下段容器（1b）からのガスバブリングを止め
て上段容器（1a）へのバブリングを停止すると共に下段
容器（1b）を減圧させると、溶融金属（３）は細管
（２）を介して下段容器（1b）内へ移動する。この時下
段容器（1b）は、その中を更に減圧し、溶融金属（３）
を該容器（1b）中に吸引するように落下させると共に、
該溶融金属（３）中に微細ガス気泡を発生させ、且つ脱
ガスをも合わせて行なう。その後浮上してくる介在物を
除去する。Thereafter, when gas bubbling from the lower vessel (1b) is stopped and bubbling to the upper vessel (1a) is stopped and the pressure in the lower vessel (1b) is reduced, the molten metal (3) is passed through the lower pipe (2) through the lower pipe (2). Move into container (1b). At this time, the lower vessel (1b) is further depressurized, and the molten metal (3)
Is dropped into the container (1b) so as to be sucked,
Fine gas bubbles are generated in the molten metal (3), and degassing is also performed. Thereafter, the floating inclusions are removed.
又第２発明は、溶融金属（３）が上段容器（1a）から
下段容器（1b）へ落下するのに、溶融金属（３）の自重
や下段容器（1b）中の減圧による吸引力を利用するだけ
では落下時間が長く掛かるので、上段容器（1a）内に不
活性ガスを導入して上から圧力を掛け、該溶融金属
（３）を強制的に落下せしめるようにしている。In the second invention, the molten metal (3) falls from the upper vessel (1a) to the lower vessel (1b) by utilizing the own weight of the molten metal (3) and the suction force due to the reduced pressure in the lower vessel (1b). If it takes only a long time to drop, the inert gas is introduced into the upper vessel (1a), pressure is applied from above, and the molten metal (3) is forcibly dropped.
このように二段重ねの容器（1a）（1b）を用いて溶融
金属の清浄化方法を実施する場合、両容器（1a）（1b）
をつないでいる細管（２）を細く、且つ下段容器（1b）
内のガス吹き込み圧を十分高くしておけば、前記上段容
器（1a）内の溶融金属（３）に対しバブリングしている
時に、該溶融金属（３）は下段容器（1b）内へ漏出して
しまうことがない。従つて上段容器（1a）内では、バブ
リングによる溶融金属（３）中の通常介在物の浮上と、
ガスの溶け込みが十分に行なわれる。一方下段容器（1
b）のガス抜きを行なつて上段容器（1a）へのバブリン
グを停止すると、はじめて溶融金属（３）は細管（２）
を通つて下段容器（1b）に移動するが、下段容器（1b）
内の減圧をこの時に開始すると該容器（1b）からの吸引
力が高まり、溶融金属（３）の移動が速くなつて良い。
更にその移動を速めようとするたらば、第２発明のよう
に上段容器（1a）内で溶融金属（３）に対しその上から
圧力を掛ける処理が必要である。When the method for cleaning molten metal is carried out using the two-stage containers (1a) and (1b) as described above, both containers (1a) and (1b)
The thin tube (2) connecting the two is thin and the lower container (1b)
If the gas blowing pressure in the inside is set sufficiently high, when the molten metal (3) in the upper vessel (1a) is bubbled, the molten metal (3) leaks into the lower vessel (1b). I won't. Therefore, in the upper vessel (1a), floating of the normal inclusions in the molten metal (3) by bubbling,
The gas is sufficiently dissolved. Meanwhile, the lower container (1
When the bubbling to the upper vessel (1a) is stopped by performing the degassing of b), the molten metal (3) becomes thin tubes (2) for the first time.
To the lower vessel (1b) through the lower vessel (1b)
When the decompression of the inside is started at this time, the suction force from the vessel (1b) is increased, and the movement of the molten metal (3) may be faster.
If the movement is to be further accelerated, it is necessary to apply a pressure to the molten metal (3) from above in the upper vessel (1a) as in the second invention.
以下本発明の具体的実施例につき説明する。 Hereinafter, specific examples of the present invention will be described.
第２図は溶鋼の清浄化を行なう本発明法の実施設備の
一例を示している。FIG. 2 shows an example of equipment for implementing the method of the present invention for cleaning molten steel.
当該設備は、内径2m、高さ3mの耐火物からなる密閉容
器（10a）（10b）二つを上下に重ね合わせて、その間を
径20mmの細管（20）25本（図では１本のみ表示）で連通
せしめた構成からなり、両容器（10a）（10b）はフレー
ム（40）で支持されている。又上段の容器（10a）の上
面には、該容器（10a）内へArガスの吹き込みを行なう
供給管（11）、そこから該ガスの排出を行なう排出管
（12）及び該容器（10a）内への未処理溶鋼（30）を供
給する注湯管（13）が接続されている。他方、下段容器
（10b）の側面上方には、その中にArガス:70％、H2ガ
ス:30％からなる混合ガスを吹き込む吹込み管（14）及
びその中のガスを抜き出し、更にその中の減圧を行なう
抜出し管（15）が接続されている。The equipment is composed of two closed vessels (10a, 10b) made of refractory with an inner diameter of 2m and a height of 3m, which are stacked one on top of the other, with 25 tubes (20) having a diameter of 20mm between them (only one is shown in the figure). ), And both containers (10a) (10b) are supported by a frame (40). On the upper surface of the upper vessel (10a), a supply pipe (11) for blowing Ar gas into the vessel (10a), a discharge pipe (12) for discharging the gas therefrom, and the vessel (10a) A pouring pipe (13) for supplying untreated molten steel (30) into the inside is connected. On the other hand, on the side surface above the lower container (10b), Ar gas therein: 70%, H 2 gas: blow pipe for blowing a mixed gas consisting of 30% (14) and withdrawing the gas therein, further that An extraction pipe (15) for reducing the pressure inside is connected.
この設備では、吹込み管（14）及び抜出し管（15）に
よつて下段容器（10b）内のガスパージが行なわれた
後、該下段容器（10b）内が前記混合ガスで2.5気圧程度
になるように調整する。この時、上段容器（10a）で
も、供給管（11）及び排出管（12）によつて内部がガス
パージされてArガスで満たされるようにする。それと共
に、注湯管（13）から溶鋼（30）を上段容器（10a）内
に供給する。その供給量としては径2m×高さ2m重量50to
n程度とすると良い。そして上段容器（10a）内のガス雰
囲気を0.6気圧程度とすると、下段容器（10b）側から細
管（20）を通つて溶鋼（30）中へ前記混合ガスがバブリ
ングされることになる。この時、両容器（10a）（10b）
内の圧力差と溶鋼（30）量、細管（20）の径とのバラン
スがちようどとれることで、溶鋼（30）が下段容器（10
b）内へ漏出してしまうことがなく、該溶鋼（30）は上
段容器（10a）内で混合ガスによるバブリングが行なわ
れることになる。In this equipment, after the gas in the lower vessel (10b) is purged by the blowing pipe (14) and the extraction pipe (15), the pressure in the lower vessel (10b) becomes about 2.5 atm with the mixed gas. Adjust as follows. At this time, the inside of the upper vessel (10a) is also gas-purged by the supply pipe (11) and the discharge pipe (12) so as to be filled with Ar gas. At the same time, the molten steel (30) is supplied from the pouring pipe (13) into the upper vessel (10a). The supply amount is 2m in diameter x 2m in height and 50to in weight
It is good to be about n. When the gas atmosphere in the upper vessel (10a) is set to about 0.6 atm, the mixed gas is bubbled from the lower vessel (10b) side through the thin tube (20) into the molten steel (30). At this time, both containers (10a) (10b)
The balance between the pressure difference in the inside, the amount of molten steel (30), and the diameter of the thin tube (20) can be balanced.
b) The molten steel (30) is bubbled by the mixed gas in the upper vessel (10a) without leaking into the inside.
その後、吹込み管（14）からの混合ガスの吹き込みを
止め、抜出し管（15）により下段容器（10b）内のガス
抜きを行なう。すると上段容器（10a）から細管（20）
を通つて該下段容器（10b）に溶鋼（30）が流れること
になる。そして前記供給管（11）によるArガスの供給を
行なうと共に、抜き出し管（15）によつて下段容器（10
b）内のガス抜きを更に続け、容器（10b）内雰囲気を1t
orr程度に減圧する。ただし、溶鋼（30）の深さが0.4m
以下になつたらArガスの供給を止め、上段容器（10a）
についても減圧を開始する。溶鋼が抜けきるまでには10
torr以下にすることが望ましい。この減圧によつて溶鋼
（30）中から微細ガス気泡（主にH2ガス）が発生し、同
時に溶鋼（30）の脱ガスも行なわれるため、しばらく放
置する。その後、容器を傾斜させ溶鋼（30）を取出口
（図中省略）より取り出す。Thereafter, the blowing of the mixed gas from the blowing pipe (14) is stopped, and the gas in the lower vessel (10b) is vented by the discharging pipe (15). Then, from the upper container (10a) to the thin tube (20)
Then, the molten steel (30) flows into the lower vessel (10b). Then, the Ar gas is supplied through the supply pipe (11), and the lower vessel (10) is supplied through the extraction pipe (15).
b) Continue degassing the inside of the container (10b) and set the atmosphere to 1t.
Reduce the pressure to about orr. However, the depth of molten steel (30) is 0.4m
When the following conditions are reached, stop the supply of Ar gas and the upper vessel (10a)
Also, pressure reduction is started. 10 by the time the molten steel comes out
It is desirable to set it to torr or less. Due to this reduced pressure, fine gas bubbles (mainly H 2 gas) are generated from the molten steel (30), and the molten steel (30) is simultaneously degassed. Thereafter, the container is tilted and the molten steel (30) is taken out from the outlet (omitted in the figure).
以上の処理で当初該溶鋼（30）中のトータル酸素量は
80ppm程度であつたものが、10ppm程度に低減されること
になつた。By the above processing, the total oxygen content in the molten steel (30) initially becomes
What was about 80 ppm has been reduced to about 10 ppm.
以上詳述した本発明の清浄化方法によれば、ストツパ
等の消耗品を使用することがなく、且つ二つの容器が連
通した状態でも溶融金属の清浄化が効率良くなされるた
め、装置のメンテナンスに手間・暇がかからず、しかも
当該方法の実施中に溶融金属の容器間の移動が不可能と
なるような事故は起こらないことになる。According to the cleaning method of the present invention described in detail above, since the consumables such as the stopper are not used and the molten metal is efficiently cleaned even in a state where the two containers are connected, the maintenance of the apparatus is performed. In addition, no trouble or time is required, and an accident that makes it impossible to move the molten metal between the containers during the execution of the method does not occur.
第１図は本発明法の実施設備の構成を示す説明図、第２
図は本発明法の実施設備の一構成例を示す正断面図、第
３図は溶融金属の清浄化法の実施に当初用いられた装置
構成を示す説明図である。 図中（1a）（1b）（10a）（10b）（100）（101）は容
器、（２）（20）は細管、（３）は溶融金属、（30）は
溶鋼、（200）はストツパを各示す。FIG. 1 is an explanatory view showing the configuration of the equipment for implementing the method of the present invention, and FIG.
FIG. 1 is a front sectional view showing an example of a configuration of equipment for implementing the method of the present invention, and FIG. 3 is an explanatory view showing an apparatus configuration initially used for implementing a method for cleaning molten metal. In the figure, (1a), (1b), (10a), (10b), (100) and (101) are containers, (2) and (20) are thin tubes, (3) is molten metal, (30) is molten steel, and (200) is a stopper. Are shown below.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 松野 秀寿 東京都千代田区丸の内１丁目１番２号 日本鋼管株式会社内 (56)参考文献 特開 平１−170556（ＪＰ，Ａ) 特公 昭58−48609（ＪＰ，Ｂ２) ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hidetoshi Matsuno 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. −48609 (JP, B2)
Claims (2)
細管でつないだ処理設備を用い、最初に上段容器内に溶
融金属を入れて該容器内を大気圧もしくはそれ以下に圧
力調整し、この時下段容器から前記細管を介して上段容
器内の溶融金属中にそれに可溶なガスをバブリングする
と共に、上段容器へのバブリングを止めて該容器から細
管を介して下段容器内に溶融金属を移し、該容器内を急
速に減圧した後浮上してくる介在物を除去することを特
徴とする二段重ね容器を用いた溶融金属の減圧清浄化方
法。1. Using a processing facility in which airtight containers are stacked in two stages vertically and connected by a thin tube, a molten metal is first placed in the upper container, and the pressure in the container is adjusted to atmospheric pressure or lower. At this time, a gas soluble in the molten metal in the upper vessel is bubbled from the lower vessel through the thin tube to the molten metal in the upper vessel, and bubbling to the upper vessel is stopped, and the molten metal is melted from the vessel into the lower vessel through the thin tube. A method for purifying molten metal under reduced pressure using a two-tiered container, comprising transferring a metal, rapidly depressurizing the inside of the container, and removing inclusions that float.
管でつないだ処理設備を用い、最初に上段容器内に溶融
金属を入れて該容器内を大気圧もしくはそれ以下に圧力
調整し、この時下段容器から前記細管を介して上段容器
内の溶融金属中にそれに可溶なガスをバブリングすると
共に、上段容器へのバブリングを止め、且つ該上段容器
内に不活性ガスを導入して上から圧力を掛けることで該
容器から細管を介して下段容器内に溶融金属を強制的に
移し、更に該容器内を急速に減圧した後浮上してくる介
在物を除去することを特徴とする二段重ね容器を用いた
溶融金属の減圧清浄化方法。2. Using a processing facility in which closed vessels are stacked in two stages vertically and connected between them by a thin tube. First, molten metal is put in the upper vessel and the pressure in the vessel is adjusted to atmospheric pressure or lower. At this time, while bubbling a gas soluble in the molten metal in the upper vessel from the lower vessel through the thin tube into the upper vessel, stopping the bubbling to the upper vessel, and introducing an inert gas into the upper vessel. By applying pressure from above, the molten metal is forcibly transferred from the vessel to the lower vessel via a thin tube, and furthermore, the inside of the vessel is rapidly depressurized, and thereafter, the floating substances are removed. A vacuum cleaning method for molten metal using a two-tiered container.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25080888A JP2718097B2 (en) | 1988-10-06 | 1988-10-06 | Vacuum cleaning method for molten metal using two-tiered container |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25080888A JP2718097B2 (en) | 1988-10-06 | 1988-10-06 | Vacuum cleaning method for molten metal using two-tiered container |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0299265A JPH0299265A (en) | 1990-04-11 |
| JP2718097B2 true JP2718097B2 (en) | 1998-02-25 |
Family
ID=17213355
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25080888A Expired - Lifetime JP2718097B2 (en) | 1988-10-06 | 1988-10-06 | Vacuum cleaning method for molten metal using two-tiered container |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2718097B2 (en) |
-
1988
- 1988-10-06 JP JP25080888A patent/JP2718097B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0299265A (en) | 1990-04-11 |
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