JP4388173B2 - Magnesia-carbonaceous unfired brick for lining of molten steel vacuum degassing equipment - Google Patents
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Description
【０００１】
【発明の属する技術分野】
本発明は、マグネシア−炭素質不焼成れんがおよびこれを用いて内張りした溶鋼真空脱ガス装置に関する。
【０００２】
【従来の技術】
溶鋼容器等の内張りとして、マグネシア−炭素質不焼成れんがが知られている。このれんが材質はマグネシアがもつ耐食性と炭素による耐スポーリング性の効果が相まって、優れた耐用性を発揮する。
【０００３】
しかし、れんが中の炭素成分が溶鋼中に溶出するカーボンピックアップにより、鋼製品の品質低下を招く問題がある。例えば溶鋼真空脱ガス装置の内張りとして使用した場合、この真空脱ガス装置が溶鋼処理の最終工程のため、鋼製品の品質に与える影響は特に大きい。
【０００４】
そこで、炭素含有量を少なくしてカーボンピックアップを抑え、しかも炭素低減に伴う耐スポーリング性の低下を膨張黒鉛の使用で解決することが提案されている（例えば特開平8-81256号公報、特開平9-41031号公報）。
【０００５】
【発明が解決しようとする課題】
膨張黒鉛は、鱗状黒鉛を数十倍に膨張させたものである。耐火物への添加は、これを粉砕で微細化した薄肉膨張黒鉛が使用される。微細化したことで同じ黒鉛量でも粒子数が増え、耐火物組織内に間断なく分布する結果、カーボンピックアップの原因となる黒鉛量を増やすことなく耐スポーリング性を向上させることができる。
【０００６】
一方、マグネシア−炭素質不焼成れんがにおいて、酸化防止および組織の緻密化を目的としてアルミニウム粉を添加することが知られている。アルミニウム粉は高温下で酸化し、Ａｌ2Ｏ3となり、この酸化による酸素の消費で炭素原料の酸化を防止する。また、アルミニウム粉の一部は炭素原料と反応し、アルミニウムカーバイド（Ａｌ4Ｃ3）を生成し、その生成に伴う体積膨張で耐火物組織を緻密化する。
【０００７】
しかし、この薄肉膨張黒鉛使用のマグネシア−炭素質不焼成れんがは、真空脱ガス装置の内張りとしての使用条件下では、酸化防止および耐スポーリング性の効果に於いて決して十分なものではない。本発明は、真空脱ガス装置の内張りにおいて、耐酸化性および耐スポーリング性に優れたマグネシア−炭素質不焼成れんがを得ることを目的とする。
【０００８】
【課題を解決するための手段】
本願発明は、膨張黒鉛を粉砕した扁平な構造を持ち厚さが１０μｍ以下の薄肉膨張黒鉛１〜１５重量％、前記薄肉膨張黒鉛以外の炭素原料0〜１０重量％、残部をマグネシア主体とし、かつ前記薄肉膨張黒鉛を含めた炭素原料の合量を１５重量％以下とした耐火骨材１００重量部に、粒径０．１ｍｍ以下のアトマイズ型アルミニウム粉１〜８重量部および結合剤を添加し、混練、成形後、加熱乾燥して製造される溶鋼真空脱ガス装置内張り用マグネシア−炭素質不焼成れんがである。アトマイズ型の構造は球体および／または楕円体である。本発明ではアトマイズ型で、しかも、粒径０．１ｍｍ以下のものを使用する。
【０００９】
アルミニウム粉は炭素原料との反応でアルミニウムカーバイドを生成すると、その分、炭素原料の酸化防止に必要なアルミニウム粉が消費され、マグネシア−炭素質不焼成れんがに対する酸化防止効果が低減する。
【００１０】
薄肉膨張黒鉛は扁平な構造であり、しかも微細化して使用することで、通常の炭素原料に比べてアルミニウム粉と反応しやすくなり、酸化よりもアルミニウムカーバイドの生成が優先する。このことが、酸化防止効果が十分でない原因と考えられる。
【００１１】
また、薄肉膨張黒鉛とアルミニウム粉とが反応しやすいことでアルミニウムカーバイドの生成が過多となり、耐火物組織が必要以上に緻密化し、耐スポーリング性の効果が低減する。
【００１２】
アルミニウム粉はその粒子形状から、フレーク型とアトマイズ型が知られている。フレーク型は扁平構造、アトマイズ型の構造は球体および／または楕円体である。本発明ではアトマイズ型で、しかも、粒径０．１ｍｍ以下のものを使用する。また、後述する薄肉膨張黒鉛との反応抑制の効果を顕著にするために、その短径／長径の比は０．２以上であることが好ましい。
【００１３】
アトマイズ型アルミニウム粉は、球体あるいは楕円体であることで比表面積が小さい。このため、薄肉膨張黒鉛との接触面積が少なくなり、薄肉膨張黒鉛との過度の反応が防止される。
【００１４】
真空脱ガス装置の槽内は、減圧下操業で酸素分圧が低い。マグネシア−炭素質不焼成れんがに添加されるアルミニウム粉は、酸素分圧の低い雰囲気下では酸素不足により、炭素原料との反応が特に優先し、耐スポーリング性の低下原因となるアルミニウムカーバイドの生成が著しい。
【００１５】
本発明はアルミニウム粉と薄肉膨張黒鉛との反応を抑制したことで、減圧下操業での過度のアルミニウムカーバイド生成を防止する。そして、このアルミニウムカーバイド生成の抑制作用が減圧下操業される真空脱ガス装置の内張りにおいて、耐火物組織の必要以上の緻密化を防止し、耐スポーリング性を向上させる。
【００１６】
さらに、このアルミニウムカーバイド生成の抑制は、炭素原料の酸化防止に対するアルミニウム粉の供給量が増し、酸化防止の効果を十分なものにする。
【００１７】
また、以上の効果はアトマイズ型アルミニウム粉と薄肉膨張黒鉛との存在下で生じるものであって、アトマイズ型アルミニウム粉を使用しても、薄肉膨張黒鉛と違って反応性の低い鱗状黒鉛等との組み合わせでは本発明の効果を得ることができない。
【００１８】
【発明の実施の形態】
薄肉膨張黒鉛は、鱗状黒鉛をその組織間に硫酸等を含ませた状態で急激に加熱し、数十倍あるいは百倍以上に膨張させたものである。市販品からも入手することができる。本発明はこの膨張黒鉛を粉砕し、薄肉膨張黒鉛として使用する。その厚さは10μｍ以下が好ましい。
【００１９】
薄肉でない膨張黒鉛を使用した場合は、れんが組織内での分散性に欠け、耐スポーリング性および耐摩耗性の効果が不十分となる。
【００２０】
耐火骨材に占める薄肉膨張黒鉛の割合は、1重量％未満では耐スポーリング性に劣り、15重量％を超えるとカーボンピックアップ防止の効果が得られない。
【００２１】
前記薄肉膨張黒鉛と共に、さらに他の炭素原料を10重量％以下範囲で組合わせてもよい。その場合、カーボンピックアップ防止のために、薄肉膨張黒鉛を含めた炭素原料の合量は15重量％以下とする。
【００２２】
薄肉膨張黒鉛以外の炭素原料の具体例は、鱗状黒鉛、土状黒鉛、膨張黒鉛、電極屑、カーボンブラック、ピッチコークス、メソフェーズカーボン、無煙炭、等である。
【００２３】
マグネシアの具体例は、電融または焼結のマグネシア、マグネシア−カルシア等である。中でも電融マグネシアが好ましい。電融マグネシアは焼結マグネシアに比べて単結晶粒が大きく、緻密組織のために耐食性により優れている。
【００２４】
マグネシアの粒径は従来のマグネシア−炭素質不焼成れんがと特に変わりなく、緻密なれんが組織が得られるように粗粒、中粒、微粒に適宜調整する。
【００２５】
耐火骨材は、以上の炭素原料とマグネシアを主材とするが、本発明の効果を損なわない範囲であれば、さらに炭化珪素、スピネル、アルミナ等を組合わせてもよい。例えば炭化珪素を0.5〜8重量％以下の範囲で組合わせ使用する。
【００２６】
炭化珪素は高温下で分解（ＳｉＣ＋Ｏ2→ＳｉＯ2＋Ｃ）し、この分解で生成したＳｉＯ2がガラス化し、炭素原料に対する酸化防止被膜となって、耐酸化性をより一層向上させる。
【００２７】
アルミニウム粉は、本発明ではアトマイズ型アルミニウム粉を使用する。その添加割合は、耐火骨材100重量部に対して1重量部未満では耐火物組織の緻密化が不十分となって強度付与の効果に劣り、8重量部を超えるとアルミニウム粉自体は低融物であることから耐食性低下の原因となる。
【００２８】
アトマイズ型アルミニウム粉の粒径は0.1ｍｍ以下とする。0.1ｍｍを超えると、アルミニウムあるいはこれが酸化して生成するアルミナが大きな塊として耐火物組織に介在し、耐食性を低下させる。
【００２９】
アトマイズ型アルミニウム粉のさらに好ましい粒径は、この粒径0.1ｍｍ以下の範囲内において、平均粒径が0.005〜0.07ｍｍである。平均粒径が過度に小さいと、アトマイズ型アルミニウム粉といえども比表面積が大きくなり、本発明の効果が十分に発揮されない。
【００３０】
なお、これらのアルミニウム粉の粒径は、標準篩あるいはレーザ回折粒度測定装置等で測定することができる。
【００３１】
以上の他にも、必要によってはガラス粉、チタン、チタン化合物、ホウ化物、窒化物、アルミニウム繊維、カーボン繊維等を添加してもよい。
【００３２】
混練に際しては以上の配合物にフェノール樹脂、ピッチ、タール等の結合剤を添加する。その添加割合は、耐火骨材100重量部に対し1〜5重量部が好ましい。混練後は加圧プレス等にて任意形状に成形後、150〜500℃程度で加熱乾燥し、不焼成品を得る。
【００３３】
【実施例】
表1は本発明実施例、表2はその比較例である。表には併せて各例の試験結果を示す。各例は表に示す耐火骨材100重量部に対し、結合剤としてフェノール樹脂を添加して混練、加圧成形（フリクションプレス）後、約250℃で加熱乾燥して不焼成れんがを得た。試験方法は次ぎのとおり。
【００３４】
耐酸化性：一辺50ｍｍの立方体に切り出した試験片を電気炉内で1400℃×4時間加熱し、冷却後の切断面から酸化層の厚さを測定した。比較例1の酸化層の厚さを100とした指数で示し、数値が小さいほど耐酸化性に優れる。
【００３５】
耐スポーリング性：試験片を誘導炉にて1600℃で溶解した溶鋼中に１分間浸漬後、水中に浸漬する加熱−水冷を繰り返し、これを試験片の浸漬部が剥落するまで繰り返した。
【００３６】
耐食性は、重量比で鋼片：転炉スラグを1：1で組み合わせたものを誘導炉にて1600℃に溶解し、この溶解物に試験片を一定時間浸漬し、試験片の溶損寸法を測定した。比較例1の溶損寸法を100とした指数で示し、数値が小さいほど耐食性に優れる
【００３７】
実機耐用性：ＲＨ式溶鋼真空脱ガス装置の下部槽に内張りし、側壁部の溶鋼湯面部位の損耗速度をｍｍ／チャージで求めた。また、使用後れんがを観察し、耐酸化性と耐スポーリング性とについて、4段階に評価した。
【００３８】
表1の試験結果から、本発明実施例は耐酸化性、耐スポーリング性および実機試験においていずれも優れた結果が得られた。また、実機耐用性からは、本発明によるれんが材質は、溶鋼真空脱ガス装置の内張りにおいてその耐酸化性、耐スポーリング性からもたらされる耐用性の向上が顕著であることが確認される。
【００４１】
また、中でも炭化珪素を併用した実施例では、耐酸化性においてさらに効果的であることがわかる。
【００４２】
これに対し、薄肉膨張黒鉛とフレーク型アルミニウム粉を組合わせた比較例1は耐酸化性、耐スポーリング性共に本発明実施例より劣っている。比較例2はアトマイズ型アルミニウム粉を使用するが、炭素原料が鱗状黒鉛であることで、耐スポーリング性および耐食性に劣る。
【００４３】
比較例3は、薄肉膨張黒鉛の割合が多過ぎ、耐酸化性に劣る。比較例4はアトマイズ型アルミニウム粉の割合が多過ぎるために、耐食性に劣る。
【００４４】
表3は、実施例および比較例より得られたれんが材質について、真空度0.2Ｔｏｒｒで高温加熱（1600℃）したものと、この高温加熱を行なわないものを、それぞれ耐酸化性試験を行なった結果である。
【００４５】
【表３】
この表3に示した試験結果からも、例えば薄肉膨張黒鉛とフレーク型アルミニウム粉を組合わせた比較例1、鱗状黒鉛とアトマイズ型アルミニウム粉を組合わせた比較例2に比べて、本発明実施例の材質は減圧下での耐酸化性の向上が歴然としている。
【００４７】
【発明の効果】
本発明によるマグネシア−炭素質不焼成れんがは、低カーボン配合組成において耐酸化性および耐スポーリング性に優れた効果を得ることができる。また、その効果は真空脱ガス装置の内張りとしての用途において特に顕著である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnesia-carbonaceous unfired brick and a molten steel vacuum degassing apparatus lined using the same.
[0002]
[Prior art]
As a lining for molten steel containers and the like, magnesia-carbonaceous unfired brick is known. This brick material combines the effects of magnesia's corrosion resistance and carbon spalling resistance, and exhibits excellent durability.
[0003]
However, the carbon pickup in which the carbon component in the brick elutes into the molten steel has a problem of degrading the quality of the steel product. For example, when it is used as a lining of a molten steel vacuum degassing apparatus, this vacuum degassing apparatus has a particularly large influence on the quality of steel products because of the final process of the molten steel treatment.
[0004]
Therefore, it has been proposed to reduce the carbon content to suppress the carbon pickup, and to solve the decrease in the spalling resistance accompanying the reduction of carbon by using expanded graphite (for example, Japanese Patent Application Laid-Open No. 8-81256). (Kaihei 9-41031).
[0005]
[Problems to be solved by the invention]
Expanded graphite is obtained by expanding scale-like graphite several tens of times. For the addition to the refractory, a thin-walled expanded graphite obtained by pulverizing it is used. As a result of refinement, the number of particles increases even with the same amount of graphite, and as a result of being distributed without interruption in the refractory structure, the spalling resistance can be improved without increasing the amount of graphite that causes carbon pickup.
[0006]
On the other hand, in magnesia-carbonaceous unfired bricks, it is known to add aluminum powder for the purpose of preventing oxidation and densifying the structure. The aluminum powder is oxidized at a high temperature to become Al 2 O 3 , and oxygen consumption due to this oxidation prevents oxidation of the carbon raw material. Also, some of the aluminum powder reacts with the carbon source to produce an aluminum carbide (Al 4 C 3), to densify the refractory tissue volume expansion caused by the generation.
[0007]
However, this magnesia-carbonaceous unfired brick using thin-walled expanded graphite is not sufficient in terms of antioxidation and spalling resistance effects under the conditions of use as the lining of a vacuum degassing apparatus. An object of the present invention is to obtain a magnesia-carbonaceous non-fired brick having excellent oxidation resistance and spalling resistance in the lining of a vacuum degassing apparatus.
[0008]
[Means for Solving the Problems]
The present invention has a flat structure in which expanded graphite is pulverized and has a thickness of 1 to 15 μm of thin expanded graphite having a thickness of 10 μm or less ; To 100 parts by weight of a refractory aggregate in which the total amount of carbon raw materials including the thin expanded graphite is 15% by weight or less, 1 to 8 parts by weight of atomized aluminum powder having a particle size of 0.1 mm or less and a binder are added, This is a magnesia-carbonaceous non-fired brick for lining of a molten steel vacuum degassing apparatus produced by kneading, forming and drying by heating. The atomized structure is a sphere and / or an ellipsoid. In the present invention, an atomizing type having a particle size of 0.1 mm or less is used.
[0009]
When aluminum carbide produces aluminum carbide by reaction with a carbon raw material, the aluminum powder necessary for the oxidation prevention of the carbon raw material is consumed correspondingly, and the antioxidant effect on magnesia-carbonaceous unfired brick is reduced.
[0010]
Thin-walled expanded graphite has a flat structure, and when used in a refined form, it becomes easier to react with aluminum powder than a normal carbon raw material, and the production of aluminum carbide has priority over oxidation. This is considered to be a cause of insufficient antioxidant effect.
[0011]
Moreover, since the thin expanded graphite and the aluminum powder are likely to react with each other, the production of aluminum carbide becomes excessive, the refractory structure becomes denser than necessary, and the effect of the spalling resistance is reduced.
[0012]
From the particle shape of aluminum powder, flake type and atomized type are known. The flake type is a flat structure, and the atomized type structure is a sphere and / or an ellipsoid. In the present invention, an atomizing type having a particle size of 0.1 mm or less is used. Further, in order to make the effect of suppressing the reaction with the thin-walled expanded graphite, which will be described later, remarkable, the ratio of the minor axis / major axis is preferably 0.2 or more .
[0013]
Atomized aluminum powder has a small specific surface area because it is a sphere or an ellipsoid. For this reason, the contact area with the thin expanded graphite is reduced, and excessive reaction with the thin expanded graphite is prevented.
[0014]
In the tank of the vacuum degassing apparatus, the oxygen partial pressure is low during operation under reduced pressure. Aluminum powder added to magnesia-carbonaceous non-fired bricks produces aluminum carbide that causes a decrease in spalling resistance due to the lack of oxygen in an atmosphere with a low oxygen partial pressure, giving priority to reactions with carbon materials. Is remarkable.
[0015]
The present invention suppresses the reaction between the aluminum powder and the thin-walled expanded graphite, thereby preventing excessive aluminum carbide generation during operation under reduced pressure. And in the lining of the vacuum degassing apparatus operated under reduced pressure, this aluminum carbide generation inhibiting action prevents the refractory structure from becoming unnecessarily dense and improves the spalling resistance.
[0016]
Furthermore, the suppression of the aluminum carbide generation increases the supply amount of aluminum powder for the oxidation prevention of the carbon raw material, and makes the oxidation prevention effect sufficient.
[0017]
In addition, the above effects occur in the presence of atomized aluminum powder and thin expanded graphite. Even if atomized aluminum powder is used, unlike thin expanded graphite, it has low reactivity with scale-like graphite. The effect of the present invention cannot be obtained by the combination.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Thin-walled expanded graphite is obtained by rapidly heating scaly graphite with sulfuric acid or the like between its structures to expand it several tens or hundred times. It can also be obtained from commercial products. In the present invention, this expanded graphite is pulverized and used as thin expanded graphite. The thickness is preferably 10 μm or less.
[0019]
When non-thin expanded graphite is used, the brick has poor dispersibility in the structure, and the effects of spalling resistance and wear resistance are insufficient.
[0020]
If the proportion of the thin expanded graphite in the refractory aggregate is less than 1% by weight, the spalling resistance is poor, and if it exceeds 15% by weight, the effect of preventing carbon pickup cannot be obtained.
[0021]
In addition to the thin expanded graphite, another carbon raw material may be combined in a range of 10% by weight or less. In that case, to prevent carbon pickup, the total amount of carbon raw materials including thin expanded graphite is 15% by weight or less.
[0022]
Specific examples of the carbon raw material other than the thin expanded graphite are scaly graphite, earthy graphite, expanded graphite, electrode scrap, carbon black, pitch coke, mesophase carbon, anthracite, and the like.
[0023]
Specific examples of magnesia include electrofused or sintered magnesia, magnesia-calcia, and the like. Among these, electrofused magnesia is preferable. Electrofused magnesia has larger single crystal grains than sintered magnesia, and is superior in corrosion resistance due to a dense structure.
[0024]
The particle size of magnesia is not particularly different from conventional magnesia-carbonaceous unfired bricks, and is appropriately adjusted to coarse grains, medium grains, and fine grains so that a dense brick structure can be obtained.
[0025]
The refractory aggregate is mainly composed of the above carbon raw material and magnesia, but may be further combined with silicon carbide, spinel, alumina or the like as long as the effects of the present invention are not impaired. For example, silicon carbide is used in combination within a range of 0.5 to 8% by weight.
[0026]
Silicon carbide decomposes at a high temperature (SiC + O 2 → SiO 2 + C), and SiO 2 generated by this decomposition becomes vitrified to form an antioxidant coating on the carbon raw material, thereby further improving the oxidation resistance.
[0027]
As the aluminum powder, atomized aluminum powder is used in the present invention. If the addition ratio is less than 1 part by weight with respect to 100 parts by weight of the refractory aggregate, the refractory structure is not sufficiently densified and the effect of imparting strength is inferior. As a result, the corrosion resistance is reduced.
[0028]
The particle size of the atomized aluminum powder is 0.1 mm or less. When the thickness exceeds 0.1 mm, aluminum or alumina produced by oxidation of the aluminum intervenes in the refractory structure as a large lump, thereby reducing the corrosion resistance.
[0029]
A more preferable particle size of the atomized aluminum powder is an average particle size of 0.005 to 0.07 mm within the range of 0.1 mm or less. If the average particle size is excessively small, the specific surface area becomes large even in the case of atomized aluminum powder, and the effects of the present invention are not sufficiently exhibited.
[0030]
The particle size of these aluminum powders can be measured with a standard sieve or a laser diffraction particle size measuring device.
[0031]
In addition to the above, glass powder, titanium, titanium compounds, borides, nitrides, aluminum fibers, carbon fibers, and the like may be added as necessary.
[0032]
At the time of kneading, a binder such as phenol resin, pitch or tar is added to the above blend. The addition ratio is preferably 1 to 5 parts by weight per 100 parts by weight of the refractory aggregate. After kneading, it is molded into an arbitrary shape with a pressure press or the like, and then heated and dried at about 150 to 500 ° C. to obtain an unfired product.
[0033]
【Example】
Table 1 shows examples of the present invention, and Table 2 shows comparative examples. The test results of each example are also shown in the table. In each example, a phenol resin was added as a binder to 100 parts by weight of the refractory aggregate shown in the table, kneaded and pressure-molded (friction press), and then heated and dried at about 250 ° C. to obtain unfired brick. The test method is as follows.
[0034]
Oxidation resistance: A test piece cut into a cube having a side of 50 mm was heated in an electric furnace at 1400 ° C. for 4 hours, and the thickness of the oxide layer was measured from the cut surface after cooling. The index is represented by an index with the thickness of the oxide layer of Comparative Example 1 being 100. The smaller the value, the better the oxidation resistance.
[0035]
Spalling resistance: The test piece was immersed in molten steel melted at 1600 ° C. in an induction furnace for 1 minute, and then repeatedly heated and cooled in water, and this was repeated until the immersed part of the test piece was peeled off.
[0036]
Corrosion resistance is a ratio of steel slab: converter slag in a weight ratio of 1: 1, melted at 1600 ° C in an induction furnace, and immersed in this melt for a certain period of time. It was measured. Indicated by an index with the erosion dimension of Comparative Example 1 as 100, the smaller the value, the better the corrosion resistance.
Actual machine durability: Lined in the lower tank of the RH-type molten steel vacuum degassing apparatus, the wear rate of the molten steel surface portion of the side wall was determined in mm / charge. In addition, bricks were observed after use, and were evaluated in four grades for oxidation resistance and spalling resistance.
[0038]
From the test results shown in Table 1, the examples of the present invention were excellent in oxidation resistance, spalling resistance, and actual machine tests. Moreover, it is confirmed from the actual machine durability that the brick material according to the present invention is remarkably improved in durability due to its oxidation resistance and spalling resistance in the lining of the molten steel vacuum degassing apparatus.
[0041]
Moreover, it turns out that the Example which used silicon carbide together is further effective in oxidation resistance.
[0042]
In contrast, Comparative Example 1 in which thin-walled expanded graphite and flake-type aluminum powder were combined was inferior to the inventive examples in both oxidation resistance and spalling resistance. Comparative Example 2 uses atomized aluminum powder, but is inferior in spalling resistance and corrosion resistance because the carbon raw material is scaly graphite.
[0043]
In Comparative Example 3, the proportion of thin-walled expanded graphite is too large and the oxidation resistance is poor. Comparative Example 4 is inferior in corrosion resistance because the proportion of atomized aluminum powder is too large.
[0044]
Table 3 shows the results of an oxidation resistance test on the brick materials obtained from the examples and comparative examples, which were heated at a high temperature (1600 ° C.) at a vacuum degree of 0.2 Torr and those not subjected to this high temperature heating. It is.
[0045]
[Table 3]
From the test results shown in Table 3, also, for example, compared to Comparative Example 1 in which thin expanded graphite and flaky aluminum powder are combined, Comparative Example 2 in which scaly graphite and atomized aluminum powder are combined, the present invention example The material of this material has clearly improved the oxidation resistance under reduced pressure.
[0047]
【The invention's effect】
The magnesia-carbonaceous unfired brick according to the present invention can obtain an effect excellent in oxidation resistance and spalling resistance in a low carbon blend composition. In addition, the effect is particularly remarkable in the use as the lining of the vacuum degassing apparatus.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24903599A JP4388173B2 (en) | 1999-09-02 | 1999-09-02 | Magnesia-carbonaceous unfired brick for lining of molten steel vacuum degassing equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24903599A JP4388173B2 (en) | 1999-09-02 | 1999-09-02 | Magnesia-carbonaceous unfired brick for lining of molten steel vacuum degassing equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001072474A JP2001072474A (en) | 2001-03-21 |
| JP4388173B2 true JP4388173B2 (en) | 2009-12-24 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24903599A Expired - Lifetime JP4388173B2 (en) | 1999-09-02 | 1999-09-02 | Magnesia-carbonaceous unfired brick for lining of molten steel vacuum degassing equipment |
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| JP (1) | JP4388173B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2072482A1 (en) * | 2007-12-17 | 2009-06-24 | Evonik Degussa GmbH | Mixture and fire-resistant moulds made from the mixture or masses with high hydration resistance |
| KR101350471B1 (en) | 2012-12-20 | 2014-01-15 | 주식회사 포스코 | Refractory composition of sliding nozzle plate for casting special steel |
| CN104870398A (en) | 2013-01-16 | 2015-08-26 | 黑崎播磨株式会社 | Magnesia-carbon brick |
| JP6154772B2 (en) * | 2014-03-28 | 2017-06-28 | 黒崎播磨株式会社 | Alumina-silicon carbide-carbon brick |
| CN104987087A (en) * | 2015-06-10 | 2015-10-21 | 马鞍山金晟工业设计有限公司 | Pressure resistant anti-fracture sliding plate fireproof material and preparation method thereof |
| CN116410008A (en) * | 2023-04-24 | 2023-07-11 | 鞍山市和丰耐火材料有限公司 | Long-service-life low-carbon magnesia carbon brick and preparation method thereof |
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1999
- 1999-09-02 JP JP24903599A patent/JP4388173B2/en not_active Expired - Lifetime
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| JP2001072474A (en) | 2001-03-21 |
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