JPH11158533A - Iron-cesium-aluminum alloy for steel making and method for adding cesium to molten steel - Google Patents
Iron-cesium-aluminum alloy for steel making and method for adding cesium to molten steelInfo
- Publication number
- JPH11158533A JPH11158533A JP33664597A JP33664597A JPH11158533A JP H11158533 A JPH11158533 A JP H11158533A JP 33664597 A JP33664597 A JP 33664597A JP 33664597 A JP33664597 A JP 33664597A JP H11158533 A JPH11158533 A JP H11158533A
- Authority
- JP
- Japan
- Prior art keywords
- alloy
- mass
- steel
- molten steel
- molten
- 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
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、鉄鋼を溶製する際
に合金添加材あるいは精錬用添加材として用いるＦｅ−
Ｃｅ−Ａｌ合金、およびその合金を用いた溶鋼への歩留
の良いＣｅ添加方法に関するものである。[0001] The present invention relates to an Fe-based alloy used as an alloy additive or a refining additive when smelting steel.
The present invention relates to a Ce—Al alloy and a method of adding Ce to a molten steel using the alloy with a good yield.
【０００２】[0002]
【従来の技術】Ｃｅは高Ａｌ含有フェライト系ステンレ
ス鋼の耐高温酸化性を向上する元素として知られ、また
鉄鋼精錬においては優れた脱酸・脱硫能を発揮すること
から、溶鋼に添加して使用される機会が増えつつある。
通常、溶鋼に希土類元素を添加する場合、Ｃｅ，Ｌａ，
Ｎｄ等を主成分とするミッシュメタルとして添加する事
が多いが、特にＣｅを選択的に添加する場合には、従来
Ｍ−Ｃｅ(＝メタルＣｅ；純Ｃｅ)を添加していた。2. Description of the Related Art Ce is known as an element for improving the high-temperature oxidation resistance of high Al-containing ferritic stainless steel, and exhibits excellent deoxidizing and desulfurizing ability in steel refining. Opportunities for use are increasing.
Usually, when a rare earth element is added to molten steel, Ce, La,
It is often added as a misch metal containing Nd or the like as a main component. Particularly, when Ce is selectively added, M-Ce (= metal Ce; pure Ce) has conventionally been added.
【０００３】[0003]
【発明が解決しようとする課題】しかし、Ｍ−Ｃｅは極
めて活性であり、しかも融点が７９８℃と溶鋼温度より
かなり低いこともあって、そのまま溶湯上から添加する
とスラグや大気中の酸素と反応して急速に酸化される。
このため、溶鋼への歩留は低くなり、かつ安定しない。
したがって、多量のＭ−Ｃｅの使用が避けられない上に
Ｃｅの「成分はずれ」も生じ易い。また、Ｍ−Ｃｅは保
存も難しい。すなわち、大気中で表面が酸化するととも
に湿分とも反応し、水素を吸蔵するという問題がある。
さらに、多量のＭ−Ｃｅ添加は、精錬容器や取鍋のＭｇ
Ｏ耐火物から溶出したスラグ中のＭｇＯの還元反応(次
式)を促し、鋼中のＭｇ濃度を高める。 ３(ＭｇＯ)＋２Ｃｅ→(Ｃｅ2Ｏ3)＋３Ｍｇ その結果、凝固時に過飽和になったＭｇは気泡を生成
し、特にスラブ表層付近に生成した管状気泡は熱延時に
ヘゲ疵となって製品品質を劣化させる。このためスラブ
の重研削を余儀なくされ、これが製品歩留を著しく低下
させる要因となっている。However, M-Ce is extremely active, and its melting point is 798 ° C, which is considerably lower than the temperature of molten steel. Therefore, if added directly from the molten metal, it reacts with slag and oxygen in the atmosphere. It is rapidly oxidized.
For this reason, the yield to molten steel is low and unstable.
Therefore, use of a large amount of M-Ce is inevitable, and “component loss” of Ce is liable to occur. M-Ce is also difficult to store. In other words, there is a problem that the surface is oxidized in the air and reacts with moisture to absorb hydrogen.
Furthermore, the addition of a large amount of M-Ce increases the amount of Mg in the refining vessel or ladle.
The reduction reaction of MgO in the slag eluted from the O refractory (the following formula) is promoted to increase the Mg concentration in the steel. 3 (MgO) +2 Ce → (Ce 2 O 3 ) +3 Mg As a result, supersaturated Mg at the time of solidification generates bubbles, and especially tubular bubbles generated near the surface layer of the slab become scorch during hot rolling. Deteriorate product quality. For this reason, heavy grinding of the slab is inevitable, which is a factor that significantly reduces the product yield.
【０００４】一方、希土類元素等の易酸化性元素を歩留
良く溶鋼中に添加する方法として、例えば特開平８−３
３２５５１号公報に示されるように、易酸化性元素を鉄
シースで被覆したワイヤを縦型タンディッシュ内に送給
して添加する「ワイヤフィード法」や、易酸化性元素を
含む粉粒状の合金鉄を不活性ガスキャリアで吹き込む
「インジェクション法」がある。しかし、これらの方法
は特別な設備を必要とし、また添加材の形態をワイヤ状
あるいは粉粒状にしなくてはならないという欠点があ
る。On the other hand, as a method of adding an easily oxidizable element such as a rare earth element to molten steel with a high yield, for example, Japanese Patent Application Laid-Open No. Hei 8-3
As disclosed in Japanese Patent No. 32551, a "wire feed method" in which a wire coated with an oxidizable element with an iron sheath is fed into a vertical tundish and added, or a powdery alloy containing an oxidizable element There is an "injection method" in which iron is blown with an inert gas carrier. However, these methods require special equipment and have the disadvantage that the form of the additive must be in the form of wire or powder.
【０００５】そこで本発明は、溶鋼にＣｅを添加するに
際し、特殊な設備を必要とせず、Ｃｅの歩留が高くかつ
安定し、添加材の準備や保存も容易となるＣｅ添加技術
を提供する事を目的とする。Therefore, the present invention provides a technique for adding Ce to molten steel, which does not require special equipment, has a high and stable Ce yield, and facilitates the preparation and storage of the additive. For the purpose.
【０００６】[0006]
【課題を解決するための手段】上記目的は、Ｃｅ添加材
として、３０〜７０質量％のＣｅと、５〜２０質量％の
Ａｌを含有するＦｅ−Ｃｅ−Ａｌ合金を用いることによ
って達成される。特に、種々の鋼種に幅広く適用できる
「汎用性」の高いＣｅ添加材として、上記含有量範囲の
Ｃｅ，Ａｌの残部がＦｅおよび不可避的不純物からなる
組成のＦｅ−Ｃｅ−Ａｌ合金を提供する。The above object is achieved by using an Fe-Ce-Al alloy containing 30 to 70% by mass of Ce and 5 to 20% by mass of Al as a Ce additive. . In particular, the present invention provides an Fe—Ce—Al alloy having a composition in which the balance of Ce and Al in the above content ranges is Fe and unavoidable impurities, as a Ce additive having high “versatility” that can be widely applied to various steel types.
【０００７】また本発明では、溶鋼にＣｅを添加するに
際し、上記Ｆｅ−Ｃｅ−Ａｌ合金の「合金塊」を湯面上
に落下投入することを特徴とする歩留の良いＣｅ添加方
法を提供する。ここで、合金塊は、鋼の成分調整を行う
ための秤量ができ、かつ落下投入するのに適したもので
あれば良く、特にサイズ・形状・数を規定するものでは
ない。その具体例としてはインゴットをミルやハンマー
等で砕いたもの、あるいはインゴット自体等が挙げられ
る。Further, the present invention provides a method of adding Ce with a good yield, characterized in that when adding Ce to molten steel, the above-mentioned "alloy lump" of the Fe-Ce-Al alloy is dropped onto a molten metal surface. I do. Here, the alloy ingot may be any one that can be weighed to adjust the composition of the steel and that is suitable for dropping in. The size, shape, and number are not particularly specified. Specific examples thereof include those obtained by crushing an ingot with a mill or a hammer or the like, or the ingot itself.
【０００８】さらに、上記Ｃｅ添加方法が効果的に適用
できる態様として、溶鋼を特に、１５〜２６質量％のＣ
ｒと、２〜６質量％のＡｌを含有するフェライト系ステ
ンレス鋼の溶鋼に規定した発明を提供する。この場合に
おいて、Ｆｅ−Ｃｅ−Ａｌ合金塊を投入する時の溶鋼温
度は特に１５７０〜１６２０℃の範囲とすることが望ま
しい。Further, as an embodiment to which the above-mentioned Ce adding method can be effectively applied, molten steel is preferably used in the form of 15 to 26% by mass of C.
The present invention provides an invention defined as a molten steel of a ferritic stainless steel containing r and 2 to 6% by mass of Al. In this case, it is desirable that the molten steel temperature at the time of introducing the Fe-Ce-Al alloy ingot be in the range of 1570 to 1620 ° C.
【０００９】[0009]
【発明の実施の形態】前述のようにＣｅは極めて活性度
が高く、また融点も溶鋼温度よりかなり低い。ところ
が、Ｃｅは鉄と合金化することによって融点が上昇し、
しかもＣｅとＦｅは約１６００℃付近の製鋼温度におい
て均一融体を形成することが知られている。すると、Ｆ
ｅ−Ｃｅ合金を添加材として使用すれば、Ｍ−Ｃｅより
も活性度を下げた状態でＣｅを溶鋼中に添加できるもの
と考えられ、効率の良いＣｅ添加の実現が期待される。BEST MODE FOR CARRYING OUT THE INVENTION As mentioned above, Ce is extremely active, and its melting point is considerably lower than the temperature of molten steel. However, the melting point of Ce increases due to alloying with iron,
Moreover, it is known that Ce and Fe form a uniform melt at a steelmaking temperature of about 1600 ° C. Then F
If an e-Ce alloy is used as an additive, it is considered that Ce can be added to molten steel with a lower activity than M-Ce, and the realization of efficient Ce addition is expected.
【００１０】しかしながら、本発明者らがＦｅ−Ｃｅ合
金の使用を試みたところ、そのインゴットは容易に小割
りすることができず、実作業においては極めて扱いにく
い物であることがわかった。つまり、Ｆｅ−Ｃｅ合金は
比較的靱性に富んでおり、ミルやハンマー等で粉砕して
用いることができないのである。通常、製鋼工場で副原
料を添加する場合、合金バンカー等から所定量を取り出
して、コンベア等で精錬容器近くまで搬送し、ホッパ等
の送給装置にて溶湯に投入する。その際、投入原料は小
割されていないと円滑に供給することができないばかり
でなく、秤量も精度良くできない。また大きいままでは
溶鋼中への溶解性も悪くなる。一方、Ｆｅ−Ｃｅ合金イ
ンゴットを小球状に鋳造して用いる方法も考えられる
が、Ｆｅ−Ｃｅ合金は真空タンク内で溶製されるため、
小球状に鋳造することは設備的に困難である。このよう
に、Ｆｅ−Ｃｅ合金はＣｅ添加材として必ずしも適して
いない事が明らかになった。[0010] However, when the present inventors tried to use the Fe-Ce alloy, it was found that the ingot could not be easily divided into small pieces and was extremely difficult to handle in actual work. That is, the Fe—Ce alloy has relatively high toughness and cannot be used after being pulverized by a mill or a hammer. Normally, when an auxiliary material is added at a steelmaking plant, a predetermined amount is taken out of an alloy bunker or the like, transported to a place near a refining vessel by a conveyor or the like, and put into a molten metal by a feeding device such as a hopper. At that time, if the input raw material is not divided into small portions, not only can it not be supplied smoothly, but also the weighing cannot be performed with high accuracy. In addition, if it is large, the solubility in molten steel also becomes poor. On the other hand, a method of casting and using an Fe-Ce alloy ingot in a small spherical shape is also conceivable, but since the Fe-Ce alloy is melted in a vacuum tank,
Casting into small spheres is difficult in terms of equipment. Thus, it became clear that the Fe—Ce alloy was not necessarily suitable as a Ce additive.
【００１１】本発明者らは、Ｆｅ−Ｃｅ合金ではなく、
Ｆｅ−Ｃｅ−Ａｌ合金を使用することによってこのよう
な問題を解消するに至った。種々の試験の結果、特定組
成のＦｅ−Ｃｅ−Ａｌ合金は小割りが容易であること、
そして、Ｃｅの活性度が低減され、溶鋼へ落下投入して
用いるＣｅ添加材として適している事が判明したのであ
る。以下に、本発明を特定するための事項について説明
する。[0011] The present inventors, instead of Fe-Ce alloy,
The use of the Fe-Ce-Al alloy has solved such a problem. As a result of various tests, the Fe-Ce-Al alloy having a specific composition is easy to subdivide,
And it turned out that the activity of Ce was reduced, and it was suitable as a Ce additive used by being dropped into molten steel and used. Hereinafter, matters for specifying the present invention will be described.
【００１２】Ｆｅ−Ｃｅ−Ａｌ合金中のＡｌ含有量を５
質量％以上とすることにより、合金は適度に脆化し、ミ
ルやハンマー等を用いて破砕することが可能になる。さ
らにＡｌ含有量を１０質量％以上とすれば一層容易に破
砕できるようになり、投入量を微調整する上で便利とな
る。一方、Ａｌ含有量が２０質量％を超えると合金の比
重が小さくなりすぎて溶鋼中に沈みにくくなり、落下投
入にて高いＣｅ歩留を得ることが難しくなる。また、Ａ
ｌ添加を要しない鋼にも適用できる「汎用性」を持たせ
るためにも合金のＡｌ含有量は２０質量％以下とするの
が良い。さらに、合金のＡｌ含有量を１５質量％以下に
留めるとＡｌ濃度を低減すべき鋼にも適用できるように
なり、汎用性は一層高まる。以上のように、本発明のＦ
ｅ−Ｃｅ−Ａｌ合金ではＡｌ含有量を５〜２０質量％に
規定するが、破砕性を重視する場合は質量の下限を１０
質量％に、また、鋼中のＡｌ濃度増加防止を重視する場
合は含有量の上限を１５質量％にそれぞれ制限する事が
望ましい。When the Al content in the Fe—Ce—Al alloy is 5
When the content is not less than mass%, the alloy is appropriately embrittled, and can be crushed using a mill, a hammer, or the like. Further, when the Al content is 10% by mass or more, crushing can be more easily performed, which is convenient for finely adjusting the input amount. On the other hand, when the Al content exceeds 20% by mass, the specific gravity of the alloy becomes too small, so that it is difficult to sink in the molten steel, and it becomes difficult to obtain a high Ce yield by dropping. Also, A
The Al content of the alloy is preferably set to 20% by mass or less in order to have “general versatility” applicable to steel not requiring l addition. Furthermore, if the Al content of the alloy is kept at 15% by mass or less, the alloy can be applied to steel whose Al concentration is to be reduced, and the versatility is further enhanced. As described above, F of the present invention
In the case of an e-Ce-Al alloy, the Al content is specified to be 5 to 20% by mass.
It is desirable to limit the upper limit of the content to 15% by mass, respectively, when importance is placed on preventing the increase of Al concentration in steel.
【００１３】Ｆｅ−Ｃｅ−Ａｌ合金中のＣｅ含有量を７
０質量％以下にするとＣｅの活性度が低下する効果が顕
著に現れ、鋼中へのＣｅ歩留が急激に向上する。同時
に、スラグ中のＭｇＯと反応するＣｅ量が少なくなるた
め鋼中のＭｇ濃度の増加が抑制され、その結果、スラブ
中の管状気泡の生成が防止されるようになる。合金のＣ
ｅ含有量が減少するほどＣｅの活性度は低下すると考え
られ、Ｃｅ含有量を７０質量％からさらに低減していく
と鋼中へのＣｅ歩留は緩やかに向上する。しかし、合金
のＣｅ含有量の減少に伴って、必要な合金の投入量は増
加することになる。合金投入量の増加は溶鋼温度の低下
を招き、好ましくない。本発明者らの調査の結果、合金
のＣｅ含有量が３０質量％以上であれば比較的小ロット
の生産においても問題無く使用できる事が確認された。
従って、本発明のＦｅ−Ｃｅ−Ａｌ合金におけるＣｅ含
有量は３０〜７０質量％に規定する。なお、溶鋼中への
Ｃｅ歩留のチャージ間変動をより安定させるには、Ｃｅ
添加量を３０〜５０質量％の範囲とすることが望まし
い。When the Ce content in the Fe—Ce—Al alloy is 7
When the content is 0% by mass or less, the effect of lowering the activity of Ce appears remarkably, and the yield of Ce in steel is sharply improved. At the same time, since the amount of Ce reacting with MgO in the slag is reduced, the increase in the Mg concentration in the steel is suppressed, and as a result, the formation of tubular bubbles in the slab is prevented. Alloy C
It is considered that the lower the e content is, the lower the Ce activity is, and if the Ce content is further reduced from 70% by mass, the Ce yield in the steel gradually increases. However, as the Ce content of the alloy decreases, the required alloy input increases. An increase in the amount of the introduced alloy causes a decrease in the temperature of the molten steel, which is not preferable. As a result of the investigation by the present inventors, it has been confirmed that if the Ce content of the alloy is 30% by mass or more, it can be used without problem even in the production of a relatively small lot.
Therefore, the Ce content in the Fe—Ce—Al alloy of the present invention is specified to be 30 to 70% by mass. In order to further stabilize the fluctuation of Ce yield in molten steel between charges, Ce
It is desirable that the addition amount be in the range of 30 to 50% by mass.
【００１４】本発明のＦｅ−Ｃｅ−Ａｌ合金は、必要に
応じてＦｅ，Ｃｅ，Ａｌ以外の他の元素を適宜含有して
もよい。但し、Ｆｅは少なくとも５質量％以上含有する
事が望ましい。また、実質的にＦｅ，Ｃｅ，Ａｌだけか
らなる合金、すなわち上記所定量のＣｅ，Ａｌと残部Ｆ
ｅおよび不可避的不純物からなるＦｅ−Ｃｅ−Ａｌ３元
合金は、多くの鋼種に適用できる汎用性の高いものであ
る。[0014] The Fe-Ce-Al alloy of the present invention may optionally contain other elements besides Fe, Ce, and Al. However, it is desirable that Fe be contained at least 5% by mass or more. An alloy consisting essentially of Fe, Ce and Al, that is, the above-mentioned predetermined amount of Ce, Al and the balance F
The Fe-Ce-Al ternary alloy composed of e and unavoidable impurities has high versatility applicable to many steel types.
【００１５】このようなＦｅ―Ｃｅ−Ａｌ合金は、例え
ば真空誘導炉を用いてＡｒ雰囲気下で成分元素を含む原
料を溶解する方法等により得る事ができる。得られたイ
ンゴットは適度な靱性と脆性を兼ね備えているため、鋳
型から取り出す際や運搬時の取り扱いも比較的容易であ
り、かつ、破砕機やハンマー等を用いて小割りすること
ができる。小割りするサイズは、秤量ができ、湯面上
（通常はスラグの表面上）から落下投入して溶鋼に沈め
ることができ、かつ短時間で溶解するサイズとすればよ
い。すなわち、例えば粉粒状のようにあまり小さいもの
を落下投入するとスラグ中にトラップされて溶鋼中に十
分入らず、逆にあまり大きな塊では精度良い秤量ができ
ないばかりか、溶解に時間がかかりすぎることになる。
適切な小割りサイズは一概には言えないが、例えば１チ
ャージが数十トン規模の大量生産現場では３０〜５０ｍ
ｍ程度に小割りした合金塊が好適に使用できる。もっと
も、インゴット自体が小さければそのまま投入してもよ
い。Such an Fe—Ce—Al alloy can be obtained by, for example, a method of melting a raw material containing a component element in an Ar atmosphere using a vacuum induction furnace. Since the obtained ingot has both moderate toughness and brittleness, it is relatively easy to handle it when taking it out of a mold or during transportation, and it can be divided into small pieces using a crusher, a hammer, or the like. The size to be subdivided may be a size that can be weighed, dropped into the molten steel surface (usually on the surface of the slag), submerged in molten steel, and melted in a short time. That is, for example, if a very small material such as a granular material is dropped and thrown in, it is trapped in the slag and does not sufficiently enter the molten steel. Become.
An appropriate subdivision size cannot be generally specified, but for example, 30 to 50 m in a mass production site where one charge is several tens tons.
An alloy chunk small to about m can be suitably used. However, if the ingot itself is small, it may be charged as it is.
【００１６】本発明のＦｅ−Ｃｅ−Ａｌ合金は種々の鋼
種に適用できるが、中でも特に高Ａｌ含有フェライト系
ステンレス鋼の製造に適用すれば非常に効果的である。
すなわち、Ｃｒ：約１５〜２６質量％、Ａｌ：約２〜６
質量％を含有するフェライト系ステンレス鋼は耐高温酸
化性に優れる剤料として周知であり、これに微量のＣｅ
を含有させることによって酸化スケールの耐剥離性等が
著しく向上する事が知られている。しかし、そのＣｅ含
有量の適正範囲は例えば０．０５〜０．２質量％、ある
いは０．０２〜０．１５質量％というように狭いにもか
かわらず、Ｃｅの歩留は低くかつ安定しないため、ロッ
ト間の品質のバラツキや「成分外れ」が出やすいという
製造上の問題を抱えている。したがって、このような鋼
種に本発明を適用する意義は大きい。The Fe--Ce--Al alloy of the present invention can be applied to various steel types, and is particularly effective when applied to the production of high Al content ferritic stainless steel.
That is, Cr: about 15 to 26% by mass, Al: about 2 to 6%
The ferritic stainless steel containing about 10% by mass is well known as a material having excellent high-temperature oxidation resistance,
It has been known that the incorporation of a metal oxide significantly improves the peeling resistance and the like of the oxide scale. However, although the appropriate range of the Ce content is narrow, for example, 0.05 to 0.2% by mass or 0.02 to 0.15% by mass, the yield of Ce is low and unstable. In addition, there is a problem in manufacturing that lot-to-lot quality variation and "component departure" tend to occur. Therefore, the significance of applying the present invention to such steel types is significant.
【００１７】Ｃｒ：１５〜２６質量％、Ａｌ：２〜６質
量％を含有するフェライト系ステンレス鋼の溶鋼に上記
したＦｅ−Ｃｅ−Ａｌ合金塊落下投入する際、溶鋼温度
が１５７０〜１６２０℃の範囲で投入する事が望まし
い。１５７０℃未満ではＣｅ歩留に若干の向上が見られ
るものの、出鍋温度が低くなりすぎるため何らかの方法
により溶鋼温度を上昇させる必要が生じる。逆に、１６
２０℃を超えるとＣｅ歩留が下がるとともに、出鍋温度
まで溶鋼温度を下げるために静置させる等の処置が必要
となり、作業時間のロスにもなる。When the Fe-Ce-Al alloy lump is dropped into a ferritic stainless steel molten steel containing 15 to 26% by mass of Cr and 2 to 6% by mass of Al, the molten steel temperature is 1570 to 1620 ° C. It is desirable to throw in the range. If the temperature is lower than 1570 ° C., although the Ce yield is slightly improved, the temperature of the pot is too low, so that it is necessary to raise the molten steel temperature by some method. Conversely, 16
If the temperature exceeds 20 ° C., the Ce yield decreases, and it is necessary to take measures such as allowing the steel to stand to lower the temperature of the molten steel to the temperature of the ladle, resulting in a loss of work time.
【００１８】[0018]
【実施例】〔実施例１〕Ｃｅ添加材として、表１に示す
７種類のＦｅ−Ｃｅ−Ａｌ合金、および２種類のＦｅ−
Ｃｅ合金を真空誘導溶解炉を用いて溶製した。原料とし
ては電解鉄、Ｍ−Ｃｅ、電解Ａｌを用い、これらをＡｒ
雰囲気下のマグネシアるつぼ中で溶解し、鉄鋳型に鋳造
して約１２ｋｇの鋳塊を得た。分析の結果、これらの合
金中へのＣｅ歩留はほぼ１００％であった。[Example 1] Seven types of Fe-Ce-Al alloys and two types of Fe-
The Ce alloy was melted using a vacuum induction melting furnace. As raw materials, electrolytic iron, M-Ce, and electrolytic Al were used.
It was melted in a magnesia crucible under an atmosphere and cast into an iron mold to obtain an ingot of about 12 kg. Analysis showed that the Ce yield in these alloys was almost 100%.
【００１９】まず各鋳塊およびＭ−Ｃｅについてハンマ
ーによる小割りを試み、破砕が可能であるか否かを評価
した。その結果、表１中に示すとおり、Ａｌを含有しな
いＦｅ−Ｃｅ合金およびＡｌ含有量が５質量％未満のＦ
ｅ−Ｃｅ−Ａｌ合金は破砕する事ができなかったが、Ａ
ｌを５質量％以上含有するＦｅ−Ｃｅ−Ａｌ合金は全て
破砕可能であった。また、Ｍ−Ｃｅも破砕可能であっ
た。First, each ingot and M-Ce were subdivided with a hammer to evaluate whether or not crushing was possible. As a result, as shown in Table 1, the Fe—Ce alloy containing no Al and the F containing less than 5% by mass of Al
The e-Ce-Al alloy could not be crushed, but A
All of the Fe—Ce—Al alloys containing 5% by mass or more of l were crushable. M-Ce was also crushable.
【００２０】次に、破砕が可能であったＦｅ−Ｃｅ−Ａ
ｌ合金およびＭ−ＣｅをＣｅ添加材として用いて、１８
Ｃｒ―３Ａｌ鋼にＣｅを添加する実験を行った（表１の
実験Ｎｏ．１〜７）。各チャージとも、マグネシアるつ
ぼ中で１２ｋｇの１８Ｃｒ−３Ａｌ鋼を溶解し、ＣａＯ
−ＭｇＯ−Ａｌ２Ｏ３系スラグを溶鋼上に添加した後、
溶鋼温度を１６００℃に保持し、溶鋼中のＣｅ含有量が
おおよそ０．０３〜０．１質量％程度になることを目標
に、適当量のＣｅ添加材をスラグの湯面上から落下投入
した。そして、Ｃｅ添加後の溶鋼を鉄鋳型に鋳造し、鋳
塊を切断・研削して気泡の有無を確認するとともに、鋳
塊中のＣｅ濃度を分析して添加材から鋼中へのＣｅ歩留
を求めた。Next, the crushable Fe-Ce-A
1 alloy and M-Ce as Ce additive, 18
An experiment of adding Ce to Cr-3Al steel was performed (Experiment Nos. 1 to 7 in Table 1). For each charge, 12 kg of 18Cr-3Al steel was melted in a magnesia crucible and CaO
-After adding MgO-Al2O3-based slag on molten steel,
The molten steel temperature was maintained at 1600 ° C., and an appropriate amount of the Ce additive was dropped from the molten metal surface of the slag with the aim of reducing the Ce content in the molten steel to approximately 0.03 to 0.1% by mass. . Then, the molten steel after the addition of Ce is cast into an iron mold, the ingot is cut and ground to check for the presence of air bubbles, and the Ce concentration in the ingot is analyzed to determine the Ce yield from the additive to the steel. I asked.
【００２１】その結果、表１中に示すように、Ｃｅ含有
量：８０質量％の添加材を用いた場合(実験No．5)のＣ
ｅ歩留は、Ｍ−Ｃｅを用いた場合(実験No．7)と比べて
ほとんど改善されなかったのに対し、Ｃｅ添加量：７０
質量％の添加材を用いると(実験No.2)とＣｅの歩留は急
激に向上した点が注目される。また、添加材のＡｌ含有
量が３０質量％と高かった場合(実験No.6)は、比重が小
さすぎて溶鋼中に十分沈まず、Ｃｅ歩留はむしろ低下し
た。As a result, as shown in Table 1, when an additive having a Ce content of 80% by mass was used (Experiment No. 5),
The e yield was hardly improved as compared with the case where M-Ce was used (Experiment No. 7), but the amount of Ce added: 70
It is noted that the use of the additive of mass% (Experiment No. 2) sharply improved the yield of Ce. Also, when the Al content of the additive was as high as 30% by mass (Experiment No. 6), the specific gravity was too small to sufficiently sink in the molten steel, and the Ce yield was rather lowered.
【００２２】また、Ｃｅ歩留が高かったもの(実験No.1,
2,3,4)は、いずれも鋳塊中に気泡の生成が見られなかっ
た。これは、スラグ中のＭｇＯとの反応に消費されるＣ
ｅが少なく、溶鋼中のＭｇ濃度の増加が低く抑えられた
ために、凝固時にＭｇがガスとして放出されるに至らな
かったものと考えられる。Further, those having a high Ce yield (Experiment No. 1,
In 2,3,4), no bubbles were found in the ingot. This is due to the C consumed in the reaction with MgO in the slag.
It is probable that Mg was not released as a gas at the time of solidification because e was small and the increase in the Mg concentration in the molten steel was suppressed low.
【００２３】[0023]
【表１】 [Table 1]
【００２４】〔実施例２〕１チャージ；８０トン規模の
製鋼ラインにおいて、本発明のＦｅ−Ｃｅ−Ａｌ合金を
使用し、高Ａl含有フェライト系ステンレス鋼(２０質量
％Ｃｒ−５質量％Ａｌ鋼)にＣｅを添加した。まず予
め、添加材として用いるＦｅ−５０質量％Ｃｅ−１０質
量％Ａｌ合金３００ｋｇを実施例１と同様の方法で溶製
し、破砕機を用いておおよそこぶし大程度に小割した。
溶鋼へのＣｅ歩留を５０％と予測し、鋼のＣｅ添加量の
目標値；０．０８質量％に対して必要となる投入量を算
出して、小割した合金塊を秤量した。一方、ステンレス
鋼の溶鋼(８０トン)は、電気炉→転炉→真空脱ガスの工
程を経てＣｅ以外の成分調整を既に終えたものを用い
た。Example 2 1 charge; In a steel production line of 80 ton scale, a Fe-Ce-Al alloy of the present invention was used, and a high Al-containing ferritic stainless steel (20 mass% Cr-5 mass% Al steel) was used. ) Was added with Ce. First, 300 kg of an Fe-50 mass% Ce-10 mass% Al alloy used as an additive material was melted in the same manner as in Example 1, and was roughly divided into large fists using a crusher.
The Ce yield to the molten steel was predicted to be 50%, the required amount of Ce added to the target value of 0.08% by mass of Ce added to the steel was calculated, and the alloy lumps divided into small portions were weighed. On the other hand, the molten steel of stainless steel (80 tons) used had already been adjusted for components other than Ce through the steps of electric furnace → converter → vacuum degassing.
【００２５】溶鋼温度が１５８５℃の時、秤量した上記
Ｆｅ−Ｃｅ−Ａｌ合金塊を副原料投入ホッパから送給し
て、溶鋼の上に浮いているスラグの湯面上から落下投入
した。投入による溶鋼温度の低下は約３℃と小さく、全
く問題にならない程度であった。その後、連続鋳造して
スラブを得た。スラブからカットサンプルを採取し、冷
却後に表面を研削して管状気泡の生成を調べた。その結
果、管状気泡は見られなかった。また、スラブの成分分
析を行った結果、Ｃｅ含有量は０．０８５質量％であっ
た。すなわち、ほぼ目標通りのＣｅ含有量となり、実績
歩留も５３％とほぼ予測値に近く、良好な結果であっ
た。When the molten steel temperature was 1585 ° C., the weighed Fe—Ce—Al alloy ingot was fed from an auxiliary material input hopper, and dropped from a molten metal surface of a slag floating on the molten steel. The drop of the molten steel temperature due to the charging was as small as about 3 ° C., which was not a problem at all. Thereafter, continuous casting was performed to obtain a slab. A cut sample was taken from the slab, the surface was ground after cooling, and the formation of tubular bubbles was examined. As a result, no tubular bubbles were observed. Further, as a result of analyzing the components of the slab, the Ce content was 0.085% by mass. That is, the Ce content was almost as desired, and the actual yield was 53%, which was almost close to the predicted value, and was a good result.
【００２６】[0026]
【発明の効果】本発明のＦｅ−Ｃｅ−Ａｌ合金を用い
れば、活性度を低減した状態で溶鋼にＣｅを添加できる
ので、溶鋼中へのＣｅ歩留は高くかつ安定する。このた
め、Ｃｅ使用量が少なくて済み、節約になると同時に、
鋼中Ｍｇ濃度の増加が抑えられ、その結果、従来Ｃｅ添
加鋼で問題となっていた気泡の生成が防止され、高品質
のＣｅ添加鋼が容易に得られる。また「成分外れ」の出
現頻度は著しく減少し、ロット間の品質のバラツキも抑
制される。 また当該合金は小割りが容易であるため作業性は高く
維持され、しかも「落下投入」という簡単な手段で添加
できるため特殊な設備は不要である。したがって本発明
の現場への適用可能性は極めて高い。 さらに当該合金はＭ−Ｃｅに比べ酸化や水素吸蔵の程
度が軽いため、保管が容易となる。 特に本発明は、非常に優れた耐高温酸化特性を有して
いるにもかかわらず安定した製造が難しかった「Ｃｅ入
り高Ａｌ含有フェライト系ステンレス鋼」の製造を容易
にし、その普及に寄与するものである。According to the Fe-Ce-Al alloy of the present invention, Ce can be added to molten steel with reduced activity, so that the Ce yield in molten steel is high and stable. As a result, the amount of Ce used can be reduced and saved, and at the same time,
An increase in the Mg concentration in the steel is suppressed, and as a result, the generation of bubbles, which has been a problem in the conventional Ce-added steel, is prevented, and a high-quality Ce-added steel can be easily obtained. In addition, the frequency of occurrence of “component departure” is significantly reduced, and variation in quality between lots is suppressed. In addition, since the alloy is easily divided into small pieces, the workability is maintained high, and the alloy can be added by a simple means of "drop-in", so that special equipment is not required. Therefore, the applicability of the present invention to the field is extremely high. Further, since the alloy has a lighter degree of oxidation and hydrogen absorption than M-Ce, it can be easily stored. In particular, the present invention facilitates the production of “high-Al-containing ferritic stainless steel containing Ce”, which has been difficult to produce stably despite having excellent high-temperature oxidation resistance, and contributes to its widespread use. Things.
Claims (6)
０質量％を含有する製鋼用Ｆｅ−Ｃｅ−Ａｌ合金。1. Ce: 30 to 70% by mass, Al: 5 to 2
Fe-Ce-Al alloy for steel making containing 0% by mass.
０質量％を含有し、残部Ｆｅおよび不可避的不純物から
なる製鋼用Ｆｅ−Ｃｅ−Ａｌ合金。2. Ce: 30 to 70% by mass, Al: 5 to 2
Fe-Ce-Al alloy for steel making containing 0% by mass, the balance being Fe and unavoidable impurities.
０〜７０質量％、Ａｌ：５〜２０質量％を含有するＦｅ
−Ｃｅ−Ａｌ合金塊を湯面上に落下投入することを特徴
とする歩留の良いＣｅ添加方法。3. When adding Ce to molten steel, Ce: 3 is added.
Fe containing 0 to 70% by mass and Al: 5 to 20% by mass
-A method of adding Ce with a good yield, characterized by dropping a Ce-Al alloy lump onto a molten metal surface.
０〜７０質量％、Ａｌ：５〜２０質量％を含有し、残部
Ｆｅおよ不可避的不純物からなるＦｅ−Ｃｅ−Ａｌ合金
塊を湯面上に落下投入する事を特徴とする歩留の良いＣ
ｅ添加方法。4. When Ce is added to molten steel, Ce: 3 is added.
Fe-Ce-Al alloy lump containing 0 to 70% by mass and Al: 5 to 20% by mass, the balance being Fe and unavoidable impurities is dropped onto the surface of the molten metal and has a good yield. C
e Addition method.
ｌ：２〜６質量％を含有するフェライト系ステンレス鋼
の溶鋼である、請求項３または４に記載の歩留の良いＣ
ｅ添加方法。5. The molten steel contains Cr: 15 to 26% by mass, A
5. A high-yield C according to claim 3 or 4, which is a molten steel of a ferritic stainless steel containing l: 2 to 6% by mass.
e Addition method.
でＦｅ−Ｃｅ−Ａｌ合金塊を湯面上に落下投入する、請
求項５に記載のＣｅ添加方法。6. The Ce adding method according to claim 5, wherein the Fe-Ce-Al alloy ingot is dropped onto the molten metal surface at a molten steel temperature of 1570 to 1620 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33664597A JP3726258B2 (en) | 1997-11-21 | 1997-11-21 | Fe-Ce-Al alloy for steel making and method for adding Ce to molten steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33664597A JP3726258B2 (en) | 1997-11-21 | 1997-11-21 | Fe-Ce-Al alloy for steel making and method for adding Ce to molten steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11158533A true JPH11158533A (en) | 1999-06-15 |
| JP3726258B2 JP3726258B2 (en) | 2005-12-14 |
Family
ID=18301315
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33664597A Expired - Fee Related JP3726258B2 (en) | 1997-11-21 | 1997-11-21 | Fe-Ce-Al alloy for steel making and method for adding Ce to molten steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3726258B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102690966A (en) * | 2012-05-29 | 2012-09-26 | 太原理工大学 | Method for manufacturing porous foam alloy from stainless steel scrap |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017007908A1 (en) | 2015-07-09 | 2017-01-12 | Orlando Rios | Castable high-temperature ce-modified al alloys |
-
1997
- 1997-11-21 JP JP33664597A patent/JP3726258B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102690966A (en) * | 2012-05-29 | 2012-09-26 | 太原理工大学 | Method for manufacturing porous foam alloy from stainless steel scrap |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3726258B2 (en) | 2005-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9108242B2 (en) | Grain refiners for steel-manufacturing methods and use | |
| RU2230797C2 (en) | Method for steel graininess reduction, an alloy for steel graininess reduction and a method to produce the alloy for steel graininess reduction | |
| KR102410368B1 (en) | Cast iron inoculum and method of producing cast iron inoculant | |
| JP6786964B2 (en) | How to prevent blockage of continuous casting nozzle of sulfur-added steel | |
| CA1196195A (en) | Boron alloying additive for continuously casting boron steel | |
| KR102410364B1 (en) | Cast iron inoculum and method of producing cast iron inoculant | |
| JP3726258B2 (en) | Fe-Ce-Al alloy for steel making and method for adding Ce to molten steel | |
| US3459540A (en) | Production of clean fine grain steels | |
| TW202248435A (en) | Ferrosilicon vanadium and/or niobium alloy, production of a ferrosilicon vanadium and/or niobium alloy, and the use thereof | |
| JP3722329B2 (en) | Fe-La-Al alloy for steel making and La addition method to molten steel | |
| US6350295B1 (en) | Method for densifying aluminum and iron briquettes and adding to steel | |
| JP6888275B2 (en) | Manufacturing method of sulfur-added steel | |
| US4233065A (en) | Effective boron alloying additive for continuous casting fine grain boron steels | |
| JP6848369B2 (en) | Sulfur-added raw material to molten steel and manufacturing method of sulfur-added steel | |
| RU2145356C1 (en) | Method of converter melting with use of prereduced materials | |
| JP2626417B2 (en) | Graphite spheroidizing alloy in mold and graphite spheroidizing method | |
| TWI825639B (en) | Ferrosilicon vanadium and/or niobium alloy, production of a ferrosilicon vanadium and/or niobium alloy, and the use thereof | |
| US3997332A (en) | Steelmaking by the electroslag process using prereduced iron or pellets | |
| AU4111685A (en) | Production of alloy steels using chemically prepared v2 o3 as a vanadium additive | |
| JPH0125363B2 (en) | ||
| RU2058415C1 (en) | Method for production of ferroalloy containing manganese and silicon | |
| RU2230798C1 (en) | Method of steel production | |
| RU2089331C1 (en) | Charge stock for metallurgic conversion and mixture of preparation thereof | |
| SU996070A1 (en) | Steel ingot production method | |
| RU2070602C1 (en) | Mixture for production of alloy for alloyage and reduction of nickel and cobalt-containing alloys |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Effective date: 20041028 Free format text: JAPANESE INTERMEDIATE CODE: A621 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20050624 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050701 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20050825 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Effective date: 20050916 Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Effective date: 20050916 Free format text: JAPANESE INTERMEDIATE CODE: A61 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091007 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 5 Free format text: PAYMENT UNTIL: 20101007 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101007 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111007 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |