JPH05337616A - Method for supplying molten steel preventing nozzle clogging - Google Patents
Method for supplying molten steel preventing nozzle cloggingInfo
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- JPH05337616A JPH05337616A JP15085092A JP15085092A JPH05337616A JP H05337616 A JPH05337616 A JP H05337616A JP 15085092 A JP15085092 A JP 15085092A JP 15085092 A JP15085092 A JP 15085092A JP H05337616 A JPH05337616 A JP H05337616A
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- molten steel
- nozzle
- inclusions
- added
- amount
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- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、溶鋼中の非金属介在物
のノズル内面への付着を抑制しつつ溶鋼をノズルを通し
て供給する、ノズル詰まりを防止した溶鋼の供給方法に
関する。さらに詳述すれば、本発明は、鋼の連続鋳造時
のタンディッシュおよび取鍋のノズルの閉塞を防止する
ことにより、操業の安定化、効率化さらには歩留りの向
上を図ることができる、ノズル詰まりを防止した溶鋼の
供給方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying molten steel through a nozzle while suppressing non-metallic inclusions in the molten steel from adhering to the inner surface of the nozzle. More specifically, the present invention can stabilize the operation, improve efficiency, and further improve the yield by preventing clogging of the nozzles of the tundish and ladle during continuous casting of steel. The present invention relates to a method for supplying molten steel that prevents clogging.
【０００２】[0002]
【従来の技術】近年、自動車用鋼板に要求される加工
性、とりわけ深絞り性を確保するためにTiを含有した低
炭素鋼や極低炭素鋼が盛んに用いられている。これらの
Ti含有低炭素鋼やTi含有極低炭素鋼の製造では、Tiを含
有しない従来の極低炭素Alキルド鋼に比較すると、非金
属介在物に起因して、例えばフクレ疵や連続鋳造時のノ
ズルの閉塞といった問題が発生し、操業上の大きな問題
となっている。2. Description of the Related Art In recent years, low carbon steels and ultra low carbon steels containing Ti have been widely used in order to secure the workability required for steel sheets for automobiles, especially the deep drawability. these
In the production of Ti-containing low-carbon steel and Ti-containing ultra-low carbon steel, compared to conventional ultra-low-carbon Al-killed steel that does not contain Ti, due to non-metallic inclusions, for example, blister defects or nozzles during continuous casting A problem such as the blockage of the plant has occurred, which has become a major operational problem.
【０００３】例えば、現状では、0.02〜0.06％ (以下、
本明細書においては特にことわりがない限り「％」は
「重量％」を意味するものとする) のTiを含有する溶鋼
を、ノズルを通して鋳込む場合に非金属介在物によるノ
ズル閉塞が多発している。For example, at present, 0.02 to 0.06% (hereinafter,
In the present specification, unless otherwise specified, "%" means "% by weight") when molten steel containing Ti is cast through a nozzle, nozzle clogging due to non-metallic inclusions frequently occurs. There is.
【０００４】ノズル閉塞の発生原因として、Ti添加によ
り溶鋼の粘度が増加して Al2O3介在物の浮上が抑制され
ることが考えられるが、さらに、ノズル内面に付着した
Al2O3 粒子間を溶鋼が流通する際に、Ti添加によりAl2O
3 介在物と溶鋼との濡れ性が向上し、溶鋼の流通が一層
抑制されることも発生原因として考えられる。As a cause of nozzle clogging, it is considered that the addition of Ti increases the viscosity of molten steel and suppresses the floating of Al 2 O 3 inclusions.
When molten steel circulates between Al 2 O 3 particles, the addition of Ti causes Al 2 O
3 It is also considered that the wettability between the inclusions and the molten steel is improved and the flow of the molten steel is further suppressed, which is also the cause.
【０００５】また、研究発表資料「アルミ−チタン脱酸
時の介在物の析出機構」 (日本学術振興会、製鋼第19委
員会鋼中非金属介在物小委員会 第４回研究会資料、平
成３年５月20日) の第４頁には、[Ti]が0.1 ％以上にな
るとTiＮのノズル内面への付着が発生し、その量は[Ti]
の増加に伴って増加し、逆にAl2O3 量は減少していたこ
とが報告されている。In addition, the research presentation material "Precipitation mechanism of inclusions during deoxidation of aluminum-titanium" (Japan Society for the Promotion of Science, Steelmaking 19th Committee, Non-metallic Inclusions in Steel Subcommittee, 4th Study Group, Heisei) On page 4, (May 20, 2013), when [Ti] exceeds 0.1%, TiN adheres to the inner surface of the nozzle, and the amount is [Ti].
It has been reported that the amount of Al 2 O 3 decreased with the increase of Al, and conversely, the amount of Al 2 O 3 decreased.
【０００６】従来、Tiを含有する溶鋼を鋳込む場合のノ
ズル閉塞防止方法として、特開昭61−1457号公報や同63
−63558 号公報等には、溶鋼にCa合金またはCa化合物を
添加する方法が提案されている。しかし、この方法に
は、金属Caが高価であるために経済的でないこと、耐火
物と溶鋼との接触面が低融点化し溶損し易くなること、
さらにはCaを含む非金属介在物が製品欠陥の原因になる
ことといった問題があり、その実施は容易ではない。[0006] Conventionally, as a method for preventing nozzle clogging when casting molten steel containing Ti, there is disclosed in Japanese Patent Laid-Open No. 61457/1986 and 63/1987.
A method of adding a Ca alloy or a Ca compound to molten steel has been proposed in Japanese Patent Publication No. 63558 and the like. However, this method is not economical because the metal Ca is expensive, and the contact surface between the refractory and molten steel has a low melting point and easily melts,
Furthermore, there is a problem that non-metallic inclusions containing Ca may cause product defects, which is not easy to carry out.
【０００７】特開平３−17219 号公報には、タンディッ
シュノズルの閉塞を防止するために、Tiを0.010 ％以上
含有する鋼を連続鋳造するに際して鋳型への注入前に、
溶鋼にAlを添加し、鋳造量に応じた溶鋼中の[Al]が [Al]／[Ti]≧1.6 ×10-6χ2 −６×10-4χ＋0.6 (ただ
し、χ：溶鋼重量(t)) を満足する範囲となる脱酸調整を行うことにより、ノズ
ル閉塞を防止する技術が提案されている。JP-A-3-17219 discloses that in order to prevent clogging of a tundish nozzle, when steel containing 0.010% or more of Ti is continuously cast before injection into a mold,
When Al is added to the molten steel, the [Al] in the molten steel according to the casting amount is [Al] / [Ti] ≥ 1.6 × 10 -6 χ 2 -6 × 10 -4 χ + 0.6 (where χ: molten steel weight A technique has been proposed for preventing nozzle clogging by adjusting deoxidation within a range satisfying (t).
【０００８】[0008]
【発明が解決しようとする課題】しかし、特開平３−17
219 号公報により提案された技術では、[Al]／[Ti]の下
限を溶鋼重量との関係で規定しており、溶鋼重量が100
トン以下の場合には、この式により規定される下限値よ
り小さな[Al]／[Ti]値で鋳込みを行わざるを得ない可能
性があり、この場合には採用できないため、適用に限界
がある。[Problems to be Solved by the Invention] However, Japanese Patent Laid-Open No. 3-17
In the technology proposed by Japanese Patent No. 219, the lower limit of [Al] / [Ti] is defined in relation to the molten steel weight, and the molten steel weight is 100
If it is less than ton, there is a possibility to have to cast with [Al] / [Ti] value smaller than the lower limit value defined by this formula. is there.
【０００９】ここに、本発明の目的は、Ti含有低炭素鋼
やTi含有極低炭素鋼といったノズル詰まりが問題である
鋼種について、溶鋼中の非金属介在物のノズル内面への
付着を抑制しつつ溶鋼をノズルを通して供給することが
できる、ノズル詰まりを防止した溶鋼の供給方法を提供
することにあり、例えば、鋼の連続鋳造時のタンディッ
シュおよび取鍋にそれぞれ設けられた溶鋼供給用のノズ
ルの閉塞を防止することにより、操業の安定化、効率化
さらに歩留りの向上を図ることができる、ノズル詰まり
を防止した溶鋼の供給方法を提供することにある。It is an object of the present invention to suppress adhesion of non-metallic inclusions in molten steel to the inner surface of the nozzle for steel types such as Ti-containing low carbon steel and Ti-containing ultra-low carbon steel in which nozzle clogging is a problem. It is to provide a molten steel supply method capable of supplying molten steel through a nozzle while preventing nozzle clogging. For example, a nozzle for supplying molten steel provided in a tundish and a ladle during continuous casting of steel. It is an object of the present invention to provide a method for supplying molten steel in which nozzle clogging is prevented, by which the operation can be stabilized, the efficiency can be improved, and the yield can be improved by preventing the clogging.
【００１０】[0010]
【課題を解決するための手段】本発明者らは、前述の研
究発表資料の第４頁に記載された事実、すなわちTiの歩
留り向上のためにAl添加後にTiを添加するという事実と
溶鋼中のアルミナクラスタがTiを添加することにより小
径化するという事実とに基づいて鋭意研究を重ねた結
果、Ｎ含有量を適当な範囲に抑制した溶鋼にAl、Tiをこ
の順に添加して[Ti]を増加せしめ、[Al]:0.02 ％以上、
[Ti]:0.005〜1.0 ％、T.O:0.01％以下の溶鋼を用いれ
ば、たとえ溶鋼中でTiＮが生成してもノズル詰まりを生
じるには至らず、Ti添加を行わない溶鋼と同等かそれ以
上の耐ノズル詰まり性が得られることを知見し、さらに
鋭意検討を重ねて本発明を完成した。[Means for Solving the Problems] The present inventors described the fact described on page 4 of the above-mentioned research presentation material, that is, the fact that Ti is added after Al addition in order to improve the yield of Ti and in molten steel. As a result of intensive studies based on the fact that the alumina clusters of No. 1 have a smaller diameter when Ti is added, Al and Ti are added in this order to molten steel in which the N content is suppressed within an appropriate range, and [Ti] Increase [Al]: 0.02% or more,
If molten steel with [Ti]: 0.005 to 1.0% and TO: 0.01% or less is used, nozzle clogging does not occur even if TiN is generated in the molten steel, and it is equal to or higher than molten steel without Ti addition. It was found that the above nozzle clogging resistance can be obtained, and further intensive studies were conducted to complete the present invention.
【００１１】ここに、本発明の要旨とするところは、例
えばタンディッシュ等の溶鋼収容容器に収容された、Ｎ
含有量：0.0016重量％以下の溶鋼にAlを添加し、その後
にTiを添加することにより、溶鋼のAl含有量：0.02重量
％以上、Ti含有量：0.005 重量％以上1.0 重量％以下、
トータル酸素含有量(T.O) ≦0.01重量％としてから、ノ
ズルを通して溶鋼を供給することを特徴とするノズル詰
まりを防止した溶鋼の供給方法である。Here, the gist of the present invention is that N contained in a molten steel container such as a tundish is stored.
Content: 0.0016 wt% or less of molten steel by adding Al, and then by adding Ti, Al content of molten steel: 0.02 wt% or more, Ti content: 0.005 wt% or more and 1.0 wt% or less,
A method for supplying molten steel which prevents nozzle clogging, characterized in that molten steel is supplied through a nozzle after the total oxygen content (TO) ≤ 0.01% by weight.
【００１２】[0012]
【作用】以下、本発明を作用効果とともに詳述する。な
お、以降の本発明の説明は、溶鋼をノズルを通して供給
する例として、タンディッシュ内溶鋼をタンディッシュ
ノズルを介して鋳型に注入する態様 (鋳込み) を用いて
行うが、これは説明の便宜上のためであり、本発明はか
かる態様にのみ限定されるものではない。本発明は、こ
の態様以外にも、例えば取鍋から直接鋳型へ溶鋼を供給
する態様や、取鍋からタンディッシュに溶鋼を供給する
態様等にも等しく適用できる。The operation of the present invention will be described in detail below. In the following description of the present invention, as an example of supplying molten steel through a nozzle, a mode of injecting molten steel in a tundish into a mold through a tundish nozzle (casting) is used, but this is for convenience of explanation. This is because the present invention is not limited to this mode. In addition to this aspect, the present invention is equally applicable to, for example, an aspect in which molten steel is directly supplied from a ladle to a mold, an aspect in which molten steel is supplied from a ladle to a tundish, and the like.
【００１３】本発明では、溶鋼にAl−Ti脱酸を行うに際
して、まずTiの歩留り向上を図るためにAl添加した後、
Tiを添加する。In the present invention, when Al-Ti deoxidation is performed on molten steel, first Al is added in order to improve the yield of Ti, and thereafter,
Add Ti.
【００１４】図１および図２は、前述の研究発表資料の
第11頁に記載された、Alを添加後2.5 分間経過時にTiを
添加した場合の[Al]、[Ti]およびT.O の経時的変化を、
またTiを添加後５分間経過時にAlを添加した場合の[A
l]、[Ti]およびT.O の経時的変化を、それぞれ示すグラ
フである。なお、溶鋼のＮ量は0.0011％であった。FIGS. 1 and 2 show the time course of [Al], [Ti] and TO when Ti was added 2.5 minutes after Al was added as described on page 11 of the above-mentioned research presentation material. Change
In addition, when Al is added 5 minutes after Ti is added, [A
1] is a graph showing changes over time in [], [Ti], and TO, respectively. The N content of the molten steel was 0.0011%.
【００１５】図２から明らかなように、Tiを添加してか
らAlを添加すると、AlはTiよりも脱酸力が強い元素であ
るために形成されたTi酸化物がAlにより還元され、図１
のAl添加後にTiを添加する場合と比較すると、[Ti]が大
きく変動してしまう。そこで、本発明では、添加するTi
の歩留り向上および[Ti]の安定化を図って所定量の[Ti]
を確保するため、Al添加後にTiを添加する。As is clear from FIG. 2, when Ti is added first and then Al is added, the Ti oxide formed is reduced by Al because Al is an element having a stronger deoxidizing power than Ti. 1
Compared with the case where Ti is added after the addition of Al, [Ti] varies greatly. Therefore, in the present invention, the Ti added
Of a predetermined amount of [Ti] to improve the yield and stabilize [Ti]
To ensure that, Ti is added after Al is added.
【００１６】ところで、タンディッシュの浸漬ノズルへ
の介在物の付着量は、アルミナクラスターとTiＮとの量
に大きな影響を受ける。図３は、Al−Ti脱酸時のノズル
への介在物付着機構を解明するために、７水準の[Ti]毎
の介在物の面積率を介在物の種類毎に分けて表したグラ
フである。The amount of inclusions deposited on the tundish immersion nozzle is greatly affected by the amounts of alumina clusters and TiN. FIG. 3 is a graph showing the area ratio of inclusions for each of the seven levels of [Ti] for each type of inclusions in order to clarify the mechanism by which inclusions adhere to the nozzle during deoxidation of Al-Ti. is there.
【００１７】同図からも明らかなように、 [Ｎ] 濃度を
低下させてTiＮ生成量を減少させても溶鋼中にアルミナ
クラスターが残存しているとノズル閉塞も促進される。
そこで、Al添加後であってAlと溶鋼中の [Ｏ] との反応
が充分に進行してAl2O3 が生成した段階で、Tiを投入す
れば、溶鋼中にAl−Ti−Ｏ介在物は生成しない。Alおよ
びTiの同時添加を行うと、大きなアルミナクラスターが
生成し、その後の浮上分離が遅くなるのはAlとTiの添加
時に生成する介在物のAl−Ti−Ｏが鋼中のAlに還元され
ていくことも原因の一つである。よって、Al添加後にAl
2O3 が生成するのに充分な時間を確保し、Al−Ti−Ｏ介
在物を生成させないために、Al添加後にTiを添加する。
Tiの添加時期は、Al添加後５〜10分間経過後とすること
が望ましい。なお、Al添加時期は何ら限定を要するもの
でなく、例えば取鍋において行ってもよく、タンディッ
シュにおいて行ってもよい。ただし、本発明を取鍋〜タ
ンディッシュへの溶鋼の供給に適用する場合には取鍋あ
るいはそれ以前の工程で行っておくことは言うまでもな
い。As is clear from the figure, even if the [N] concentration is lowered to reduce the TiN production amount, nozzle clogging is promoted if alumina clusters remain in the molten steel.
Therefore, if Ti is added at a stage after the addition of Al and the reaction between Al and [O] in the molten steel has progressed sufficiently to form Al 2 O 3 , Al-Ti-O intercalation occurs in the molten steel. Nothing is created. When Al and Ti are added at the same time, large alumina clusters are formed and the subsequent floating separation is delayed because Al-Ti-O, which is an inclusion formed when Al and Ti are added, is reduced to Al in the steel. Going is one of the causes. Therefore, after adding Al, Al
Ti is added after the addition of Al in order to secure a sufficient time for the formation of 2 O 3 and to prevent the formation of Al—Ti—O inclusions.
It is desirable that Ti is added 5 to 10 minutes after the addition of Al. The timing of adding Al is not particularly limited, and may be, for example, in a ladle or in a tundish. However, it goes without saying that when the present invention is applied to the supply of molten steel to a ladle to a tundish, it is carried out in the ladle or in a step prior thereto.
【００１８】次に、Al添加後にTiを添加した場合の[Ti]
とノズル内面の介在物付着量 (付着厚さ) との関係を図
４にグラフで示す。なお、溶鋼のＮ量は0.0015％であっ
た。図４から、[Ti]が0.01％以上0.05％以下のときに介
在物付着量が略最小になること、および[Ti]が１％のと
きの介在物付着量は０％の場合と同程度になることがわ
かる。[Ti] when Ti is added after Al is added
FIG. 4 is a graph showing the relationship between the amount of inclusions (adhesion thickness) on the inner surface of the nozzle. The N content of the molten steel was 0.0015%. From Fig. 4, the amount of inclusions is approximately minimum when [Ti] is 0.01% or more and 0.05% or less, and the amount of inclusions when [Ti] is 1% is about the same as when 0%. It turns out that
【００１９】[Ti]が0.01％以上0.05％以下の時に介在物
付着量が最小になるのは、酸素活量係数と[Ti]との関係
をグラフで示す図５から明らかなように、Tiを添加する
ことにより溶鋼中の酸素の活量が低下するため、 Al2O3
の表層が分解して付着介在物であるAl2O3 が小さくなる
ためと考えられる。When [Ti] is 0.01% or more and 0.05% or less, the amount of inclusions is minimized as shown in FIG. 5, which is a graph showing the relationship between oxygen activity coefficient and [Ti]. The addition of Al reduces the oxygen activity in the molten steel, so Al 2 O 3
It is considered that the surface layer of is decomposed and Al 2 O 3 as an adhering inclusion becomes smaller.
【００２０】また、[Ti]が１％のときの介在物付着量が
０％のときの介在物付着量と同程度になるのは、前述の
ようにTiを添加することによりAl2O3 が小さくなるが、
Al2O3 が小さくなっても[Ti]が0.1 ％以上ではTiＮが生
成するため、ノズル内面へのTiＮの付着が促進されるた
めであると考えられる。Further, the amount of inclusions when [Ti] is 1% is almost the same as the amount of inclusions when 0% is Al 2 O 3 by adding Ti as described above. Becomes smaller,
It is considered that TiN is generated when the amount of [Ti] is 0.1% or more even when Al 2 O 3 is small, and therefore the adhesion of TiN to the inner surface of the nozzle is promoted.
【００２１】そこで、本発明では、このTiＮの生成を阻
止することを目的として、鋼中の[N] を0.0016％以下に
抑制する。すなわち、[N] が0.0016％以下の溶鋼にAl、
Tiの順に添加を行って、溶鋼中の[Al]：0.02％以上、[T
i]： 0.005〜1.0 ％としてから、ノズルを通して溶鋼を
供給する。Therefore, in the present invention, [N] in steel is suppressed to 0.0016% or less for the purpose of preventing the formation of TiN. That is, Al in molten steel with [N] of 0.0016% or less,
Ti is added in order, and [Al] in molten steel: 0.02% or more, [T
i]: 0.005 to 1.0%, and then feed molten steel through the nozzle.
【００２２】しかし、前述の図４中の斜線付丸印は、他
の本発明例と同様にsol.Al≦0.02％であって[Ti]はおよ
そ0.5 ％程度であるが、ノズルへの介在物付着量は多
い。この斜線付丸印と、[Ti]が略同等の３点の丸印との
相違点はT.O であった。ここで、介在物量とT.O との関
係は概ね比例していると考えられるため、鋳込み前の溶
鋼中の介在物数を調査した。結果を図６にグラフで示
す。However, the circles with diagonal lines in FIG. 4 described above have sol.Al ≦ 0.02% and [Ti] of about 0.5% as in the other examples of the present invention. The amount of deposits is large. The difference between this shaded circle and the three-point circle with approximately the same [Ti] was the TO. Here, since the relationship between the amount of inclusions and TO is considered to be approximately proportional, the number of inclusions in the molten steel before casting was investigated. The results are shown graphically in FIG.
【００２３】図６から分かるように、sol.Alや[Ti]で溶
鋼中の濃度を抑制しても元の溶鋼の介在物量が多ければ
ノズルへの付着量の増加は免れない。そこで、本発明で
は、介在物付着量とT.O との関係に基づいて鋳込み前溶
鋼のT.O を0.01％以下と限定する。As can be seen from FIG. 6, even if the concentration in the molten steel is suppressed by sol.Al or [Ti], an increase in the amount of deposits on the nozzle cannot be avoided if the amount of original molten steel inclusions is large. Therefore, in the present invention, TO of the molten steel before casting is limited to 0.01% or less based on the relationship between the amount of inclusions and TO.
【００２４】以上のようにして、Ｎ含有量：0.0016％以
下の溶鋼にAlを添加し、その後にTiを添加することによ
り、溶鋼のAl含有量：0.02％以上、Ti含有量：0.005 ％
以上1.0 ％以下、トータル酸素含有量T.O:0.01％以下と
してから、ノズルを通して前記溶鋼を供給することによ
り、ノズルの閉塞を防止することができ、操業の安定
化、効率化さらに歩留りの向上を図ることができる。As described above, by adding Al to molten steel having N content of 0.0016% or less and then adding Ti, Al content of molten steel: 0.02% or more, Ti content: 0.005%
By supplying the molten steel through the nozzle after setting the total oxygen content to 1.0% or less and the total oxygen content TO: 0.01% or less, it is possible to prevent nozzle clogging, stabilize operation, improve efficiency, and improve yield. be able to.
【００２５】さらに、本発明を実施例を参照しながら詳
述するが、これは本発明の例示であり、これにより本発
明が限定されるものではない。Further, the present invention will be described in detail with reference to examples, but this is an example of the present invention and the present invention is not limited thereto.
【００２６】[0026]
【実施例】タンディッシュに一旦溜めた溶鋼にAlを添加
後５分間経過してからTiを添加して、表１に示すＮ量、
Al量、Ti量およびT.O を有する３種類の溶鋼ａ〜ｃ各20
0kg を製造し、図７に示す断面形状のアルミナグラファ
イト製タンディッシュノズル１を通して鋳型へ鋳込ん
だ。鋳込み後にタンディッシュノズル１内における付着
介在物の厚さを測定した。付着介在物の厚さが薄ければ
薄いほどそれだけノズル注入時のノズル詰まりが防止さ
れると考えられる。結果を表２に示す。[Examples] After adding Al to molten steel once stored in a tundish, 5 minutes after the addition of Ti, the amount of N shown in Table 1 was added.
Three types of molten steel a to c with Al content, Ti content and TO 20
0 kg was manufactured and cast into a mold through an alumina graphite tundish nozzle 1 having a sectional shape shown in FIG. After casting, the thickness of adhered inclusions in the tundish nozzle 1 was measured. It is considered that the thinner the adhered inclusions, the more the nozzle clogging during the nozzle injection is prevented. The results are shown in Table 2.
【００２７】[0027]
【表１】 [Table 1]
【００２８】[0028]
【表２】 [Table 2]
【００２９】表２から明らかなように、[Ti]＝1.0 ％の
場合が[Ti]＝０％の場合より介在物付着量の点で改善さ
れ、[Ti]＝0.03％の時は介在物付着量は３種類の中で最
小となり、本発明の介在物付着防止効果が明らかであ
る。As is clear from Table 2, when [Ti] = 1.0%, the amount of inclusions is improved compared to when [Ti] = 0%. When [Ti] = 0.03%, inclusions are improved. The amount of adhesion is the smallest among the three types, and the effect of preventing inclusion adhesion of the present invention is clear.
【００３０】[0030]
【発明の効果】以上詳述したように、本発明によれば、
溶鋼をノズルを通して供給する際に、溶鋼中の非金属介
在物のノズル内面への付着を抑制ないしは防止できる。As described in detail above, according to the present invention,
When supplying molten steel through the nozzle, it is possible to suppress or prevent non-metallic inclusions in the molten steel from adhering to the inner surface of the nozzle.
【図１】Al添加後にTiを添加を行った場合の[Al]、[Ti]
およびT.O の経時的変化を示すグラフである。FIG. 1 [Al] and [Ti] when Ti is added after Al addition
3 is a graph showing changes with time in TO and TO.
【図２】Ti添加後にAlを添加を行った場合の[Al]、[Ti]
およびT.O の経時的変化を示すグラフである。[Fig. 2] [Al] and [Ti] when Al is added after Ti addition
3 is a graph showing changes with time in TO and TO.
【図３】Al−Ti脱酸時のノズルへの介在物付着機構を解
明するために、７水準の[Ti]毎の介在物の面積率を介在
物の種類毎に分けて表したグラフである。FIG. 3 is a graph showing the area ratio of inclusions for each of 7 levels of [Ti] for each type of inclusions in order to elucidate the mechanism of inclusions adhering to the nozzle during deoxidation of Al-Ti. is there.
【図４】[Ti]とノズルへの介在物付着量 (付着厚さ) と
の関係を示すグラフである。FIG. 4 is a graph showing the relationship between [Ti] and the amount of inclusions attached to nozzles (adhesion thickness).
【図５】[Ti]と鋼中酸素の活量係数との関係を示すグラ
フである。FIG. 5 is a graph showing the relationship between [Ti] and the activity coefficient of oxygen in steel.
【図６】鋳込み前の溶鋼中の介在物数を調査した結果を
示すグラフである。FIG. 6 is a graph showing the results of examining the number of inclusions in molten steel before casting.
【図７】実施例に用いたタンディッシュノズルの縦断面
形状を示す説明図である。FIG. 7 is an explanatory diagram showing a vertical sectional shape of a tundish nozzle used in Examples.
Claims (1)
を添加し、その後にTiを添加することにより、前記溶鋼
のAl含有量：0.02重量％以上、Ti含有量：0.005 重量％
以上1.0 重量％以下、トータル酸素含有量T.O ：0.01重
量％以下としてから、ノズルを通して前記溶鋼を供給す
ることを特徴とするノズル詰まりを防止した溶鋼の供給
方法。1. N content: 0.0016% by weight or less of molten steel to Al
By adding Ti and then Ti, the Al content of the molten steel: 0.02 wt% or more, Ti content: 0.005 wt%
A method for supplying molten steel which prevents nozzle clogging, characterized in that the molten steel is supplied through a nozzle after the content is 1.0% by weight or less and the total oxygen content TO: 0.01% by weight or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15085092A JP2953197B2 (en) | 1992-06-10 | 1992-06-10 | Supply method of molten steel preventing nozzle clogging |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15085092A JP2953197B2 (en) | 1992-06-10 | 1992-06-10 | Supply method of molten steel preventing nozzle clogging |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05337616A true JPH05337616A (en) | 1993-12-21 |
| JP2953197B2 JP2953197B2 (en) | 1999-09-27 |
Family
ID=15505746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15085092A Expired - Lifetime JP2953197B2 (en) | 1992-06-10 | 1992-06-10 | Supply method of molten steel preventing nozzle clogging |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2953197B2 (en) |
-
1992
- 1992-06-10 JP JP15085092A patent/JP2953197B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2953197B2 (en) | 1999-09-27 |
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