JPH0624832A - Insulting material for molten steel surface - Google Patents
Insulting material for molten steel surfaceInfo
- Publication number
- JPH0624832A JPH0624832A JP4197477A JP19747792A JPH0624832A JP H0624832 A JPH0624832 A JP H0624832A JP 4197477 A JP4197477 A JP 4197477A JP 19747792 A JP19747792 A JP 19747792A JP H0624832 A JPH0624832 A JP H0624832A
- Authority
- JP
- Japan
- Prior art keywords
- heat retaining
- retaining agent
- molten steel
- content
- sio
- 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.)
- Granted
Links
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
(57)【要約】
【目的】 本発明は、空気酸化と保温剤の反応に起因す
る溶鋼汚染を確実に防止し、その上で耐火物の損傷や溶
損ばない保温剤を提供することを目的とする。
【構成】 ＣａＯとＡｌ2Ｏ3の含有率をＣａＯ／Ａｌ2
Ｏ3で０．５〜２．０とし、且つＭｇＯ含有率を３０〜
６０％、ＳｉＯ2 含有率を１０％以下にしたことを特徴
とする溶鋼表面保温剤。(57) [Summary] [PROBLEMS] To provide a heat retaining agent that surely prevents molten steel contamination caused by a reaction between air oxidation and a heat retaining agent, and that does not damage or melt the refractory. To aim. [Structure] The content of CaO and Al 2 O 3 is changed to CaO / Al 2
And 0.5 to 2.0 with O 3, and 30 to the MgO content
A molten steel surface heat retaining agent having a SiO 2 content of 60% and a SiO 2 content of 10% or less.
Description
【０００１】[0001]
【産業上の利用分野】本発明は連続鋳造用タンディッシ
ュや取鍋などにより溶鋼を移送、又は精錬処理を行なう
際に、断熱・保温あるいは空気酸化防止を目的として溶
鋼表面を被覆する溶鋼表面保温剤に関するものである。BACKGROUND OF THE INVENTION The present invention relates to a molten steel surface heat insulation for covering the molten steel surface for the purpose of heat insulation / heat retention or air oxidation prevention when the molten steel is transferred or refined by a continuous casting tundish or ladle. It is related to agents.
【０００２】[0002]
【従来の技術】連続鋳造用タンディッシュや取鍋などに
より溶鋼を移送、又は精錬処理を行なう際、保温剤を用
いて溶鍋表面を被覆し溶鋼からの熱放散と外気の侵入を
防止している。従来から保温剤としては、籾殻を蒸し焼
きにした焼籾が主に用いられ、その主成分はＳｉＯ2と
Ｃである。ＳｉＯ2は熱伝導率が低く保温効果に、Ｃは
酸素をＣＯガスに変えるため酸素の遮断効果に優れてい
る。このため、焼籾は保温効果及び空気遮断効果を有
し、しかも安価であることを特徴とする保温剤である。2. Description of the Related Art When transferring or refining molten steel with a tundish for continuous casting or a ladle, the surface of the ladle is covered with a heat insulating agent to prevent heat dissipation from the molten steel and invasion of outside air. There is. Conventionally, as the heat retaining agent, burned rice obtained by steaming rice husks has been mainly used, and its main components are SiO 2 and C. SiO 2 has a low thermal conductivity and has a heat retaining effect, and C has an excellent oxygen blocking effect because it converts oxygen into CO gas. Therefore, burned rice has a heat retaining effect and an air blocking effect, and is a cheap heat retaining agent.
【０００３】しかしながら、加工性向上の目的から鋼板
中のＣ濃度を極力低下させた、例えばＣ濃度が５０ｐｐ
ｍ以下の極低炭素鋼において、保温剤中のＣ成分が溶鋼
中にピックアップし鋼材の特性を低下させる欠点が知ら
れている。また、保温剤中のＳｉＯ2 成分は溶鋼中のＡ
ｌと反応しＡｌ2Ｏ3系の介在物を生成するため、表面欠
陥を増大させるといった問題も生じる。However, for the purpose of improving workability, the C concentration in the steel sheet is reduced as much as possible, for example, the C concentration is 50 pp.
It is known that in the ultra low carbon steel of m or less, the C component in the heat retaining agent is picked up in the molten steel and deteriorates the properties of the steel material. Also, the SiO 2 component in the heat retaining agent is A in molten steel.
Since it reacts with l to form an Al 2 O 3 -based inclusion, there arises a problem of increasing surface defects.
【０００４】従来、焼籾のこれら欠点を解決するため、
Ｃ及びＳｉＯ2 成分の少ない保温剤として、例えば特公
平３−４８１５２号公報に記載されているように、Ｍｇ
Ｏ系の保温剤が使用されている。また、ＭｇＯ自体は熱
伝導率が高いため、これに断熱性を付与した発泡ＭｇＯ
の製造方法についても種々検討され、特公昭４８−７４
８５号公報等に記載されている。Conventionally, in order to solve these drawbacks of rice hulls,
As a heat retaining agent having a small amount of C and SiO 2 components, for example, as disclosed in Japanese Patent Publication No. 3-48152, Mg
An O-based heat retaining agent is used. Further, since MgO itself has a high thermal conductivity, foamed MgO provided with heat insulation properties
Various manufacturing methods have been investigated, and Japanese Patent Publication No.
No. 85, etc.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、ＭｇＯ
を主成分とする保温剤は融点が高く、使用温度では主に
固相であるため、溶鋼表面の均一な被覆状態が得られ
ず、外気と溶鋼との反応によりＡｌ2Ｏ3系介在物を生成
する。また、タンディッシュではモールド内への溶鋼供
給を制御するためにストッパーを使用しているが、Ｍｇ
Ｏ系保温剤は粒子間で焼結が進み強固なスラグ層を形成
するためストッパー制御が困難となり、激しい場合には
ストッパーの折損に到る。DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Since the heat-insulating agent containing as a main component has a high melting point and is mainly a solid phase at the operating temperature, a uniform coating state of the molten steel surface cannot be obtained, and Al 2 O 3 -based inclusions are generated by the reaction between the outside air and the molten steel. To generate. In the tundish, a stopper is used to control the supply of molten steel into the mold.
Since the O-based heat retaining agent is sintered between particles to form a strong slag layer, it becomes difficult to control the stopper, and when it is severe, the stopper is broken.
【０００６】これに対し、ＭｇＯの一部をＳｉＯ2 に置
き換え融点を下げる方法が考えられるが、この場合溶鋼
中ＡｌによりＳｉＯ2の還元が起こる。これらの問題を
鑑み、本発明は、空気酸化と保温剤の反応に起因する溶
鋼汚染を確実に防止し、その上で耐火物の損傷や溶損が
ない保温剤を提供することを目的とするものである。On the other hand, a method of lowering the melting point by replacing part of MgO with SiO 2 is conceivable. In this case, Al in molten steel causes reduction of SiO 2 . In view of these problems, it is an object of the present invention to reliably prevent molten steel contamination due to the reaction of air oxidation and a heat retaining agent, and to provide a heat retaining agent that does not damage or melt the refractory. It is a thing.
【０００７】[0007]
【課題を解決するための手段】本発明は、ＣａＯとＡｌ
2Ｏ3の含有率をＣａＯ／Ａｌ2Ｏ3で０．５〜２．０と
し、且つＭｇＯ含有率を３０〜６０％、ＳｉＯ2 含有率
を１０％以下にしたことを特徴とする溶鋼表面保温剤に
関するものである。The present invention is based on CaO and Al.
The content of 2 O 3 and 0.5 to 2.0 at CaO / Al 2 O 3, and the MgO content of 30% to 60%, the molten steel surface, characterized in that the SiO 2 content of 10% or less It relates to a heat retaining agent.
【０００８】[0008]
【作用】溶鋼表面を被覆する保温剤として満足すべき条
件は、空気酸化と保温剤の反応に起因する溶鋼汚染を確
実に防止し、その上で耐火物の損傷や溶損がないことで
ある。本発明者等はこれら基本条件を満足すべく保温剤
の検討を進めてきた結果、空気酸化を抑制するためには
保温剤の液相化が、保温剤と溶鋼の反応を防止するため
には低ＳｉＯ2化が有効であることを見いだした。[Function] A condition to be satisfied as a heat retaining agent for coating the surface of molten steel is that the contamination of molten steel caused by the reaction of air oxidation and the heat retaining agent is surely prevented, and further, there is no damage or melting loss of the refractory. . As a result of the inventors of the present invention having studied the heat retaining agent to satisfy these basic conditions, in order to suppress the air oxidation, the liquid phase of the heat retaining agent is required to prevent the reaction between the heat retaining agent and the molten steel. It was found that lowering SiO 2 is effective.
【０００９】すなわち、保温剤の融点を下げ液相を生成
することは溶鋼表面の被覆状態を均一化し、保温剤自体
の空気酸化防止能を高める。また、保温剤中のＳｉＯ2
は（１）式により溶鋼中のＡｌと反応するため、保温剤
の低ＳｉＯ2 化はＡｌ2Ｏ3系介在物の生成防止に効果を
有する。 ３ＳｉＯ2＋４Ａｌ＝２Ａｌ2Ｏ3＋３Ｓｉ （１）That is, lowering the melting point of the heat retaining agent to generate a liquid phase makes the coating state of the molten steel surface uniform and enhances the air oxidation preventing ability of the heat retaining agent itself. In addition, SiO 2 in the heat retaining agent
Reacts with Al in the molten steel according to the formula (1), so lowering the SiO 2 content of the heat retaining agent is effective in preventing the formation of Al 2 O 3 -based inclusions. 3SiO 2 +4 Al = 2Al 2 O 3 +3 Si (1)
【００１０】以上の点を考慮して液相化と低ＳｉＯ2 化
を満足し、さらに介在物吸収を具備する保温剤について
検討を重ねた結果、ＣａＯとＡｌ2Ｏ3の含有率をＣａＯ
／Ａｌ2Ｏ3で０．５〜２．０の範囲とし、ＳｉＯ2 含有
率を１０％以下にすることが最適であることを明らかに
した。In consideration of the above points, as a result of further studies on a heat retaining agent which satisfies the liquid phase and the low SiO 2 and has the inclusion absorption, the content of CaO and Al 2 O 3 was changed to CaO.
It has been clarified that it is optimal to set the ratio of / Al 2 O 3 to 0.5 to 2.0 and the SiO 2 content to 10% or less.
【００１１】ここに、ＣａＯ／Ａｌ2Ｏ3を０．５〜２．
０の範囲にしたのは、図１に示すように保温剤の融点が
タンディッシュにおける溶鋼温度（１５５０℃）以下と
なり、液相化するためである。また、ＳｉＯ2 含有率を
１０％以下にしたのは、図２に示すようにＳｉＯ2 の活
量が極めて小さくなり、工業的に問題となる様な保温剤
と溶鋼の反応を防止できるためである。しかし、本成分
の保温剤をタンディッシュに適用した場合、ストッパー
耐火物の溶損が急激に進行し、長時間の使用に耐えない
ことが分かった。Here, CaO / Al 2 O 3 is added in an amount of 0.5-2.
The reason for setting the range to 0 is that the melting point of the heat retaining agent becomes the molten steel temperature (1550 ° C.) or less in the tundish and becomes a liquid phase as shown in FIG. Further, the reason why the SiO 2 content is 10% or less is that the activity of SiO 2 becomes extremely small as shown in FIG. 2 and the reaction between the heat retaining agent and the molten steel, which is industrially problematic, can be prevented. is there. However, it was found that when the heat retaining agent of this component was applied to the tundish, the stopper refractory material rapidly melted and could not be used for a long time.
【００１２】そこで、本発明者らは、前述した成分の保
温剤にＭｇＯを添加し、保温剤が固相化しない範囲で融
点を上げ、ストッパー耐火物の溶損防止を検討した。そ
の結果を図３に示す。図から明らかなように、ストッパ
ー耐火物の溶損はＭｇＯを３０％以上添加することによ
り工業的に使用可能なまでに抑制できる。[0012] Therefore, the present inventors have examined the prevention of melting damage of stopper refractory by adding MgO to the above-mentioned heat retaining agent to raise the melting point within the range where the heat retaining agent does not solidify. The result is shown in FIG. As is clear from the figure, the melting loss of the stopper refractory can be suppressed to an industrial level by adding MgO in an amount of 30% or more.
【００１３】しかし、図４に示すように溶鋼温度（１５
５０℃）でＭｇＯ含有率が６０％を超えると、保温剤中
の液相は極めて少なくなる。その結果、保温剤は溶鋼表
面を均一に覆わず、外気の侵入によりＡｌ2Ｏ3系の介在
物を生成する。したがって、保温剤への最適なＭｇＯ含
有率は３０〜６０％である。また、耐火物の溶損機構に
ついても詳細な調査を実施し、耐火物気孔内への保温剤
の浸透が溶損速度を律すること、さらにＭｇＯ含有率が
３０％以上では保温剤の融点が増大し固・液共存相にな
るため液相の見掛けの粘性が高まり、耐火物気孔内への
浸透が抑制されることを見出した。However, as shown in FIG. 4, the molten steel temperature (15
When the MgO content exceeds 50% at 50 ° C., the liquid phase in the heat retaining agent becomes extremely small. As a result, the heat-retaining agent does not uniformly cover the surface of the molten steel, and Al 2 O 3 -based inclusions are generated when the outside air enters. Therefore, the optimum MgO content in the heat retaining agent is 30 to 60%. In addition, a detailed investigation was also conducted on the melting mechanism of refractory materials, and the penetration of the heat retaining agent into the pores of the refractory material regulates the rate of melt loss. Further, when the MgO content is 30% or more, the melting point of the heat retaining agent increases. It was found that the solid-liquid coexisting phase increases the apparent viscosity of the liquid phase and suppresses the penetration into the pores of the refractory.
【００１４】保温剤の基本的成分は以上に述べた通りで
あるが、本発明品の機能を低下させない範囲で、ＣａＣ
ｌ2、ＣａＦ2等の他成分の添加も可能である。以上に示
したように、本発明の保温剤を用いることにより空気酸
化と保温剤の反応に起因する溶鋼汚染を確実に防止で
き、その上で耐火物の損傷や溶損がない溶鋼保温剤を提
供できる。Although the basic components of the heat retaining agent are as described above, CaC is used as long as the function of the product of the present invention is not deteriorated.
It is also possible to add other components such as l 2 and CaF 2 . As shown above, by using the heat retaining agent of the present invention, it is possible to surely prevent molten steel contamination caused by the reaction of air oxidation and the heat retaining agent, and to provide a molten steel heat retaining agent that does not damage or melt the refractory. Can be provided.
【００１５】[0015]
【実施例】以下に、実施例及び比較例を挙げて、本発明
について説明する。表１に示す成分の保温剤４００ｋｇ
を容量６０ｔｏｎのダンディッシュに添加し、低炭アル
ミキルド鋼を４００分間鋳造した。本発明の実施例及び
比較例とも、鋳造寸法は厚み２４５ｍｍ×幅１５００ｍ
ｍで、８５００ｍｍ長さに切断して１コイル単位とし
た。このスラブを常法により熱間圧延、冷間圧延し、最
終的に厚み０．７ｍｍ×幅１５００ｍｍコイルの冷延鋼
板とした。保温剤の空気遮断効果及び反応防止効果はタ
ンディッシュ入側と出側の全酸素量の上昇量及び冷延鋼
板に発生した表面欠陥の発生個数により評価した。ま
た、耐火物の溶損については使用後ストッパーの溶損量
を測定し、鋳造時間から溶損速度を算出した。なお、鋳
造において使用したストッパー耐火物の材質はロウセキ
であった。EXAMPLES The present invention will be described below with reference to Examples and Comparative Examples. 400 kg of heat retaining agent of the ingredients shown in Table 1
Was added to a tundishes with a capacity of 60 tons, and low carbon aluminum killed steel was cast for 400 minutes. In both the example and the comparative example of the present invention, the casting dimensions are 245 mm in thickness and 1500 m in width.
In m, it was cut into a length of 8500 mm to make one coil unit. The slab was hot-rolled and cold-rolled by a conventional method to finally obtain a cold-rolled steel sheet having a thickness of 0.7 mm and a width of 1500 mm. The air blocking effect and reaction preventing effect of the heat retaining agent were evaluated by the amount of increase in total oxygen content on the tundish inlet side and outlet side and the number of surface defects generated on the cold rolled steel sheet. Further, regarding the melting loss of the refractory material, the melting loss amount of the stopper was measured after use, and the melting rate was calculated from the casting time. The material of the stopper refractory used in the casting was wax.
【００１６】 [0016]
【００１７】表２に示す如く、実施例ではＣａＯとＡｌ
2Ｏ3の含有率をＣａＯ／Ａｌ2Ｏ3で０．５〜２．０と
し、且つＭｇＯ含有率を３０〜６０％、ＳｉＯ2 含有率
を１０％以下にしたことで、空気酸化と保温剤の反応に
起因する溶鋼汚染を防止できたため、タンディッシュ内
での全酸素量の上昇及び表面欠陥の発生は全くなかっ
た。また、ストッパー耐火物の溶損速度も低下するた
め、連々鋳回数が増加する場合にも十分使用に耐えうる
ことが確認された。As shown in Table 2, in the examples, CaO and Al were used.
The content of 2 O 3 and 0.5 to 2.0 at CaO / Al 2 O 3, and the MgO content of 30% to 60%, by making the SiO 2 content of 10% or less, insulation and air oxidation Since the molten steel contamination caused by the reaction of the agent could be prevented, the total oxygen content in the tundish was not increased and surface defects were not generated at all. Further, it was confirmed that the stopper refractory material also has a low melting loss rate and can withstand sufficient use even when the number of castings is continuously increased.
【００１８】これに対し、比較例１はＭｇＯ含有率が低
かったため、ストッパー耐火物の溶損を抑えることがで
きず、保温剤投入後３５０分で鋳造を停止した。比較例
２はＭｇＯ含有率が６０％を超えたため、比較例３と比
較例４はＣａＯ／Ａｌ2Ｏ3が０．５〜２．０の範囲外で
あったため、保温剤が固相となり十分な断気効果が得ら
れず、タンディッシュ内溶鋼の全酸素量が上昇し表面欠
陥が発生した。また、比較例５はＳｉＯ2 含有率が１０
％を超えたため、溶鋼中Ａｌとの反応によりＡｌ2Ｏ3系
介在物が生成した。その結果、タンディッシュ内溶鋼の
全酸素量が増大し、表面欠陥が発生した。On the other hand, in Comparative Example 1, since the MgO content was low, the melting loss of the stopper refractory could not be suppressed, and the casting was stopped 350 minutes after the heat insulating agent was added. Since the MgO content rate of Comparative Example 2 exceeded 60%, the CaO / Al 2 O 3 content of Comparative Example 3 and Comparative Example 4 was out of the range of 0.5 to 2.0. However, the total oxygen content of the molten steel in the tundish increased and surface defects occurred. Further, Comparative Example 5 has a SiO 2 content of 10
%, The reaction with Al in molten steel produced Al 2 O 3 -based inclusions. As a result, the total oxygen content of the molten steel in the tundish increased and surface defects occurred.
【００１９】[0019]
【表２】 [Table 2]
【００２０】[0020]
【発明の効果】以上に説明したように、本発明の溶鋼保
温剤によれば溶鋼の汚染は全くなく、鋳片品質は極めて
向上する。また、耐火物の損傷や溶損も生じないため、
操業面でも有効な保温剤を提供できる。As described above, according to the molten steel heat retaining agent of the present invention, the molten steel is not contaminated at all, and the slab quality is extremely improved. In addition, since there is no damage or melting of refractories,
It is possible to provide an effective heat retaining agent in terms of operation.
【図１】保温剤のＣａＯ／Ａｌ2Ｏ3と融点の関係を示す
図、FIG. 1 is a diagram showing the relationship between CaO / Al 2 O 3 of a heat retaining agent and the melting point,
【図２】保温剤中のＳｉＯ2含有率とＳｉＯ2の活量の関
係を示す図、FIG. 2 is a graph showing the relationship between the SiO 2 content in a heat retaining agent and the activity of SiO 2 ;
【図３】保温剤中のＭｇＯ添加量と溶損速度の関係を示
す図、FIG. 3 is a diagram showing the relationship between the amount of MgO added to the heat retaining agent and the dissolution rate;
【図４】保温剤の液相率とＭｇＯ含有率の関係を示す図
である。FIG. 4 is a diagram showing the relationship between the liquid phase rate of the heat retaining agent and the MgO content rate.
Claims (1)
ｌ2Ｏ3で０．５〜２．０とし、且つＭｇＯ含有率を３０
〜６０％、ＳｉＯ2 含有率を１０％以下にしたことを特
徴とする溶鋼表面保温剤。1. The content of CaO and Al 2 O 3 is CaO / A.
L 2 O 3 to 0.5 to 2.0 and the MgO content of 30
60%, the molten steel surface insulation agent characterized in that the SiO 2 content of more than 10%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04197477A JP3081067B2 (en) | 1992-07-02 | 1992-07-02 | Liquid steel surface heat insulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04197477A JP3081067B2 (en) | 1992-07-02 | 1992-07-02 | Liquid steel surface heat insulator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0624832A true JPH0624832A (en) | 1994-02-01 |
| JP3081067B2 JP3081067B2 (en) | 2000-08-28 |
Family
ID=16375137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04197477A Expired - Fee Related JP3081067B2 (en) | 1992-07-02 | 1992-07-02 | Liquid steel surface heat insulator |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3081067B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3719561A1 (en) * | 1986-06-12 | 1988-01-21 | Morita Mfg | MEDICAL LASER HANDPIECE |
| KR20020052131A (en) * | 2000-12-23 | 2002-07-02 | 이구택 | Insulator for molten iron using by-products in ironmaking processes |
| KR100436506B1 (en) * | 1997-04-30 | 2004-08-18 | 주식회사 포스코 | Ultra low carbon special molten steel ladle insulation insulation |
| JP2007537882A (en) * | 2004-05-19 | 2007-12-27 | メタコン ゲゼルシャフト ミット ベシュレンクテル ハフツング | Method for processing molten metal |
-
1992
- 1992-07-02 JP JP04197477A patent/JP3081067B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3719561A1 (en) * | 1986-06-12 | 1988-01-21 | Morita Mfg | MEDICAL LASER HANDPIECE |
| DE3719561C2 (en) * | 1986-06-12 | 1998-12-10 | Morita Mfg | Medical light irradiation handpiece |
| KR100436506B1 (en) * | 1997-04-30 | 2004-08-18 | 주식회사 포스코 | Ultra low carbon special molten steel ladle insulation insulation |
| KR20020052131A (en) * | 2000-12-23 | 2002-07-02 | 이구택 | Insulator for molten iron using by-products in ironmaking processes |
| JP2007537882A (en) * | 2004-05-19 | 2007-12-27 | メタコン ゲゼルシャフト ミット ベシュレンクテル ハフツング | Method for processing molten metal |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3081067B2 (en) | 2000-08-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2928382B2 (en) | Continuous casting method of ultra low carbon aluminum killed steel | |
| JPH0624832A (en) | Insulting material for molten steel surface | |
| JP3317258B2 (en) | Mold powder for continuous casting of high Mn round section slabs | |
| JPH06179059A (en) | Surface insulating material for molten steel | |
| JPH06170507A (en) | Molten steel surface heat retaining agent | |
| JPH05337617A (en) | Insulating material for molten steel surface | |
| JPH07124741A (en) | Molten steel surface heat retaining agent | |
| JP3103465B2 (en) | Liquid steel surface heat insulator | |
| CN107338343B (en) | Flux and casting method using the same | |
| JPH05293616A (en) | Insulating material for molten steel surface | |
| JPS6127150A (en) | Continuous casting method of steel | |
| JP3004657B2 (en) | Powder and casting method for casting high aluminum content steel | |
| JPH0833960A (en) | Molten steel surface heat retaining agent | |
| JP4580155B2 (en) | Continuous casting nozzle | |
| JPH06170508A (en) | Molten steel surface heat retaining agent | |
| JP2007290003A (en) | Molten steel surface heat insulating material and continuous casting method of steel using the same | |
| JP3393803B2 (en) | Insulation agent for molten steel in container | |
| JPH0751819A (en) | Immersion nozzle for continuous casting | |
| JP2007111721A (en) | Molten steel surface heat insulating material and continuous casting method of steel using the same | |
| JP2007290002A (en) | Molten steel surface heat insulating material and continuous casting method of steel using the same | |
| JP4205811B2 (en) | Steel continuous casting method and continuous cast slab | |
| JP4750985B2 (en) | Molten steel surface heat insulating material and continuous casting method of steel using the same | |
| JP7380900B2 (en) | Continuous steel casting method | |
| JP2001131628A (en) | Method of preventing air oxidation of molten steel | |
| JP2001113346A (en) | Heat insulation material for molten steel and continuous casting method of steel using it |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20000613 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080623 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090623 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090623 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100623 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100623 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110623 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110623 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120623 Year of fee payment: 12 |
|
| LAPS | Cancellation because of no payment of annual fees |