JPH08143939A - Method for refining molten fe-ni alloy - Google Patents
Method for refining molten fe-ni alloyInfo
- Publication number
- JPH08143939A JPH08143939A JP6292519A JP29251994A JPH08143939A JP H08143939 A JPH08143939 A JP H08143939A JP 6292519 A JP6292519 A JP 6292519A JP 29251994 A JP29251994 A JP 29251994A JP H08143939 A JPH08143939 A JP H08143939A
- Authority
- JP
- Japan
- Prior art keywords
- refining
- slag
- less
- molten
- container
- 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
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は溶湯を、真空、または低
酸素分圧雰囲気下で精錬した後、大気圧付近でさらに精
錬するＦｅ−Ｎｉ系合金溶湯の精錬方法に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for refining a molten Fe-Ni alloy in which a molten metal is refined in a vacuum or in a low oxygen partial pressure atmosphere and then further refined near atmospheric pressure.
【０００２】[0002]
【従来の技術】真空または低酸素分圧雰囲気下での精錬
法（以下、真空または低酸素分圧下精錬と記す）では、
高レベルの清浄鋼等を容易に得ることができることから
広く用いられており、真空誘導加熱炉(ＶＩＦとも称さ
れる）はその一つの手段である。この真空または低酸素
分圧下精錬において、ある種の不純物は、それ自身また
は酸化物等の化合物となって、溶湯から蒸発、飛散また
は浮上して分離されることにより、精錬が進行する。そ
して、この場合、精錬が進行した状態では、溶湯中の不
純物（本発明で不純物とは不純元素や非金属介在物の原
因となる物質を総称する）を非常に低いレベルにするこ
とができる。2. Description of the Related Art In the refining method under vacuum or low oxygen partial pressure atmosphere (hereinafter referred to as refining under vacuum or low oxygen partial pressure),
It is widely used because high-level clean steel and the like can be easily obtained, and a vacuum induction heating furnace (also called VIF) is one of the means. In this refining under vacuum or low oxygen partial pressure, certain impurities become themselves or compounds such as oxides, and are evaporated, scattered or floated from the molten metal to be separated, whereby refining proceeds. Then, in this case, in the state where the refining has progressed, the impurities in the molten metal (impurities in the present invention are collectively referred to as substances causing impure elements or non-metallic inclusions) can be made to have a very low level.
【０００３】この真空または低酸素分圧下精錬におい
て、精錬炉の炉壁フリーボード部分には蒸発、飛散成分
の一部が凝縮してスカム状に付着している。また精錬炉
中の溶湯液面には、別種の蒸発できないドロス状等の不
純物成分が浮上して分離されている。精錬炉の傾注によ
り出湯する場合、溶湯流によりこれらの付着物や浮遊物
の一部が洗い流されて溶湯中に再度取り込まれ、溶湯中
に再混入する。さらに受湯容器である取鍋またはタンデ
ィシュの内張り耐火物は、それが受湯前に十分加熱され
ていない場合、活性ガス成分を吸着しており、またこの
耐火物は受湯後、真空または低酸素分圧下での処理によ
り活性化した溶湯と一部反応し、または溶湯に侵食され
て、これら活性ガス、反応生成物、侵食物により溶湯を
汚染する。In this refining under a vacuum or low oxygen partial pressure, a part of vaporized and scattered components are condensed and adhered in a scum-like form on the freeboard portion of the refining furnace. On the surface of the molten metal in the refining furnace, another kind of non-evaporable dross-like impurity component floats and is separated. When the molten metal is poured into the molten metal by pouring it into the molten metal, some of these deposits and suspended matters are washed away by the molten metal flow and are re-introduced into the molten metal, and are remixed in the molten metal. Furthermore, the refractory lining of the ladle or tundish, which is the hot water container, adsorbs the active gas components if it is not heated sufficiently before the hot water is received, and this refractory also has a vacuum or low oxygen content after the hot water is received. It partially reacts with the molten metal activated by the treatment under partial pressure or is corroded by the molten metal, and the active gas, reaction products, and eroded foods contaminate the molten metal.
【０００４】前記の再混入の防止方法として今日まで試
みられた方法には、精錬炉の炉底出湯を行なうととも
に、浮遊不純物の混入防止のため溶湯を一部炉内に残留
させる方法、インダクションスカル炉により溶湯を空中
出湯する方法、また、取鍋またはタンディッシュ内にお
いては、セラミックフィルタにより微小非金属介在物原
因物質を除去する方法などが提案され一部実用化されて
いるが、種々の制約があり、未だ広く採用されるに至っ
ていない。また、これらの方法はすべての再混入物質や
汚染物質等に対して有効ではないので、前記各再混入物
質等に対して有効ならしめるためには、これらを組み合
わせることが必要である。しかし、これらは組み合わせ
るほど、費用が嵩む等の問題を生ずる。また真空誘導溶
解炉では、真空精錬を行なうために、造滓剤を添加しな
いのでスラグの発生がない。したがって、脱硫を行なう
ことがほとんど不可能であるという問題がある。The methods that have been tried up to now as methods for preventing re-mixing include tapping the bottom of a refining furnace and leaving a part of the molten metal in the furnace to prevent mixing of floating impurities. A method of discharging molten metal in the air with a furnace, and a method of removing fine nonmetallic inclusion-causing substances with a ceramic filter in a ladle or a tundish have been proposed and partially put into practical use. However, it has not been widely adopted yet. Further, since these methods are not effective for all remixed substances, pollutants, etc., it is necessary to combine them in order to be effective for each remixed substance, etc. However, the more they are combined, the more costly the problem arises. Further, in the vacuum induction melting furnace, no slag is generated because no slag-forming agent is added for performing vacuum refining. Therefore, there is a problem that desulfurization is almost impossible.
【０００５】一方、真空精錬後、黒鉛電極アーク加熱方
式の取鍋精錬炉、ＡＳＥＡ−ＳＫＦ法などで再精錬する
ことで再混入物質等を除去したり、脱硫を行なうという
ことも考えられるが、これらの方法では電極が黒鉛質で
あり、その電極を溶鋼表面上のスラグ中に浸漬するの
で、脱酸、脱硫ができる反面、溶湯中への炭素のピック
アップの問題がある。また特開平4-318118号には、真空
脱ガス処理により溶湯を脱炭した後、Ｓol.Ａl≧0.2wt%
を含有させた状態で、プラズマ加熱し、塩基度8以上の
スラグの存在下で撹拌し、脱硫する極低炭素、極低硫鋼
の製造方法が提案されている。On the other hand, after vacuum refining, it is also considered that re-refining substances are removed or desulfurization is performed by refining with a ladle refining furnace of graphite electrode arc heating system, ASEA-SKF method, etc. In these methods, the electrode is graphite and the electrode is immersed in the slag on the surface of the molten steel, so that deoxidation and desulfurization can be performed, but there is a problem of carbon pickup in the molten metal. Further, in Japanese Patent Laid-Open No. 4-318118, after the molten metal is decarburized by vacuum degassing treatment, Sol.Al ≧ 0.2 wt%
A method for producing ultra-low carbon and ultra-low sulfur steel has been proposed in which, while being contained, is heated in plasma, stirred in the presence of slag having a basicity of 8 or more, and desulfurized.
【０００６】[0006]
【発明が解決しようとする課題】前記提案の方法では、
プラズマ精錬前時点でのスラグをプラズマ精錬炉に持ち
込むので、プラズマ精錬中でのＳｏｌ.Ａｌおよびスラ
グの塩基度を8以上に高くしなければならない。すなわ
ち、スラグを持ち込むので、スラグの改質のために大量
の脱酸剤をおよび還元剤を必要とするため、精錬効果が
劣る問題があった。ところで、Ｆｅ−Ｎｉ系合金など電
磁気材料と称される合金製品の中には、要求される特性
を害する理由から、炭素と硫黄をともに厳しく制限され
るものもある。SUMMARY OF THE INVENTION In the method proposed above,
Since the slag before plasma refining is brought into the plasma refining furnace, the basicity of Sol.Al and slag during plasma refining must be increased to 8 or higher. That is, since slag is brought in, a large amount of a deoxidizing agent and a reducing agent are required for modifying the slag, so that the refining effect is poor. By the way, some alloy products called electromagnetic materials such as Fe—Ni alloys are severely limited in both carbon and sulfur for the reason of impairing required characteristics.
【０００７】上記の炭素および硫黄の混入の多くは溶解
時の固体原料から持ち込まれ、精錬によって低酸素の材
料ほど脱炭を強化しなければならない。さらに低硫黄と
するにはＣａＯを主体とする造滓剤を添加して効率よく
脱硫精錬を行なう必要がある。このうち、脱炭は酸素な
どとの反応で、燃焼させる手段が知られており、さらに
減圧雰囲気や真空雰囲気と組み合わせると効率がよい。
しかし、いずれの場合も反応生成物は酸化物であり、こ
れが精錬炉の溶湯面や炉壁に付着して、溶湯の動きによ
っては溶湯中に再混入してせっかく精錬した溶湯を汚染
するという危険性が大きいものである。一方、脱硫に関
しては、前工程の予備精錬の仕方や溶湯の移動時の取扱
い方法によっては、前の工程で発生したスラグが存在す
る状態で行なうことにより、このスラグの改質に負担が
かかり、効率のよい脱硫が行なえない欠点があった。Most of the above-mentioned contamination of carbon and sulfur is brought in from a solid raw material at the time of melting, and decarburization should be strengthened as much as a material having a low oxygen content by refining. In order to further reduce sulfur, it is necessary to add a slag forming agent mainly composed of CaO for efficient desulfurization refining. Of these, decarburization is known to be a means of burning by reaction with oxygen or the like, and it is more efficient if combined with a reduced pressure atmosphere or a vacuum atmosphere.
However, in any case, the reaction product is an oxide, which adheres to the molten metal surface or wall of the smelting furnace and remixes into the molten metal depending on the movement of the molten metal, thus contaminating the smelted molten metal. It has a great nature. On the other hand, regarding desulfurization, depending on the method of pre-refining in the previous step and the handling method when moving the molten metal, by performing in the state where the slag generated in the previous step exists, a burden is imposed on the reforming of this slag. There was a drawback that efficient desulfurization could not be performed.
【０００８】しかし、上記の脱炭処理や脱硫処理を回避
しようとすると、精錬炉への挿入材料について低Ｃや低
Ｓの高級な材料を選択する必要があり、溶解するための
原料費が著しく高価になり、経済的な量産に適さない欠
点がある。本発明の目的は、重量％で少なくともＮｉ 3
0〜50%を含有するＦｅ−Ｎｉ系合金など電磁気材料と称
される製品の炭素含有量と硫黄含有量がともに厳しく制
限される鋼や合金などの精錬時に、前述の炭素のピック
アップの問題がなく、持込みスラグを改質する必要もな
く、高レベルの精錬等の場合にも柔軟に対応できるＦｅ
−Ｎｉ系合金溶湯の精錬方法を提供することである。However, in order to avoid the above-mentioned decarburization treatment or desulfurization treatment, it is necessary to select a high-grade material of low C or low S as a material to be inserted into the refining furnace, and the raw material cost for melting is remarkably high. It has the drawback of becoming expensive and not suitable for economical mass production. It is an object of the present invention to provide at least Ni 3 wt.
When refining steel or alloys where the carbon content and the sulfur content of products called electromagnetic materials such as Fe-Ni alloys containing 0 to 50% are severely limited, the problem of carbon pickup described above Fe does not need to be modified to bring in slag, and can flexibly handle high-level refining.
-To provide a refining method for a molten Ni-based alloy.
【０００９】[0009]
【課題を解決するための手段】本発明は、重量％で少な
くともＮｉ 30〜50%を含有するＦｅ−Ｎｉ系合金の溶湯
を加熱手段を有する容器中で真空または低酸素分圧雰囲
気で脱酸・脱炭精錬を行ない、引き続き別容器または前
記脱酸精錬を行なうものと同じ容器内でガスプラズマで
再精錬を行なう組合せの精錬方法である。しかし、その
内容は従来の方法とは大きく異なる。According to the present invention, a molten Fe-Ni alloy containing at least 30 to 50% by weight of Ni is deoxidized in a container having heating means in a vacuum or low oxygen partial pressure atmosphere. A combination refining method in which decarburization refining is performed, and then re-refining is performed by gas plasma in another container or in the same container in which the deoxidation refining is performed. However, the content is significantly different from the conventional method.
【００１０】本発明では、低炭素レベルに脱炭精錬を終
えた溶湯は、アーク炉や転炉のように別容器の場合には
取鍋を介して脱酸すべき容器に移し、また脱酸すべき容
器で溶解を行なった溶湯は同じ容器内で低炭素レベルに
脱炭精錬を終えた後、真空または低酸素分圧雰囲気で予
備精錬を行なって脱酸を完了する。本発明は、いずれも
Ｎｉ 30〜50%を含有して、低Ｃ化が望まれるＦｅ−Ｎｉ
系の合金を加熱手段を有する容器により真空または低酸
素分圧雰囲気中で精錬することにより、予備精錬するた
めの造滓剤を添加する必要がなく、したがって実質的に
スラグのない状態で所定のレベルの予備精錬を達成する
ところに大きな特徴がある。ところで、前述したように
真空または低酸素分圧下の予備精錬において、精錬炉の
炉壁フリーボード部分にスカム状に付着している不純物
あるいは精錬炉中の溶湯液面上に浮上しているドロス状
の不純物の他、溶湯中には浮上しきれない状態で存在す
る不純物がある。これらの不純物の中には、精錬炉の炉
壁の侵食によるＳｉＯ2がかなりの割合を占めている。In the present invention, the molten metal that has been decarburized and refined to a low carbon level is transferred to a container to be deoxidized through a ladle in the case of another container such as an arc furnace or a converter, and is also deoxidized. The molten metal that has been melted in the vessel to be deoxidized is completed by decarburizing and refining to a low carbon level in the same vessel, and then pre-refining in a vacuum or low oxygen partial pressure atmosphere. All of the present inventions contain 30 to 50% of Ni, and Fe-Ni for which lowering of C is desired is desired.
By refining the alloy of the system in a vacuum or low oxygen partial pressure atmosphere by a container having a heating means, it is not necessary to add a slag-forming agent for pre-refining, and thus a predetermined slag-free condition can be obtained. A major feature is the achievement of level pre-refining. By the way, as described above, in the pre-refining under vacuum or low oxygen partial pressure, impurities adhering to the free wall of the refining furnace in scum form or dross floating on the surface of the molten metal in the refining furnace. In addition to the impurities described above, there are impurities that exist in the molten metal in a state where they cannot completely float. Among these impurities, SiO 2 due to the erosion of the furnace wall of the refining furnace accounts for a considerable proportion.
【００１１】本発明では、予備精錬炉で造滓剤を添加し
ていないので、次のプラズマ加熱による再精錬で、スラ
グの改質をする必要がない。したがって、再精錬過程で
は、ＣａＯやＳｉＯ2を多量に添加して塩基度を8以上に
調整しなくてよく、予備精錬時に溶湯中に混入した不純
物を効率的に除去し、さらに高レベルに精錬できる利点
がある。発明者はＦｅ−Ｎｉ合金の低Ｃ化、低Ｓを検討
する中で、前記合金の予備精錬で発生し不純物の一部と
して混入した比較的少量のＳｉＯ2を利用して、次工程
のプラズマ加熱による再精錬時には、ＣａＯを必須とし
て複合組成からなる新たな造滓剤を添加して、基本的に
はＳｉＯ2を添加しないで塩基度を調整することで不純
物の改質とさらに高レベルの精錬を行なうことができる
ことを見出した。In the present invention, since the slag-forming agent is not added in the preliminary refining furnace, it is not necessary to modify the slag in the next refining by plasma heating. Therefore, in the re-refining process, it is not necessary to add CaO or SiO 2 in a large amount to adjust the basicity to 8 or more, efficiently remove the impurities mixed in the molten metal during the pre-refining, and refine it to a higher level. There are advantages. The inventor, while considering lowering C and lowering S of Fe-Ni alloy, utilizes a relatively small amount of SiO 2 generated in the pre-refining of the alloy and mixed as a part of impurities, and uses plasma in the next step. At the time of re-refining by heating, CaO is essential and a new slag-forming agent having a composite composition is added, and basically the basicity is adjusted without adding SiO 2 to improve impurities and further increase the level. It has been found that refining can be done.
【００１２】すなわち、本発明のうちの第１発明は、予
め溶解した、重量％で少なくともＮｉ 30〜50%を含有す
るＦｅ−Ｎｉ系合金の溶湯を加熱手段を有する容器へ注
湯し、該容器中で真空または低酸素分圧雰囲気で、炭素
含有量が0.01%以下まで予備精錬をした後の溶湯に、主
としてＣａＯおよびＣａＦ2、主としてＣａＯおよびＡl
2Ｏ3、または主としてＣａＯ，ＣａＦ2およびＡｌ2Ｏ3
からなるいずれかの組合せの造滓剤を添加し、ガスプラ
ズマにより加熱して再精錬を行ない、炭素 0.01%以下、
硫黄 0.005%以下にすることを特徴とするＦｅ−Ｎｉ系
合金溶湯の精錬方法である。That is, the first aspect of the present invention is to pour a previously melted molten Fe-Ni alloy containing at least 30 to 50% by weight of Ni into a container having a heating means. Mainly CaO and CaF 2 , mainly CaO and Al were added to the molten metal after pre-refining to a carbon content of 0.01% or less in a vessel in a vacuum or low oxygen partial pressure atmosphere.
2 O 3 , or mainly CaO, CaF 2 and Al 2 O 3
Add a slag forming agent in any combination consisting of, and perform refining by heating with gas plasma, carbon 0.01% or less,
A method for refining a molten Fe-Ni alloy is characterized in that the content of sulfur is 0.005% or less.
【００１３】第２発明は、予め溶解した重量％で少なく
ともＮｉ 30〜50%を含有するＦｅ−Ｎｉ系合金の溶湯を
加熱手段を有する容器へ注湯し、該容器中で真空または
低酸素分圧雰囲気で、炭素含有量が0.01%以下まで予備
精錬をした後、予備精錬時のスラグを実質的に持ち込ま
ないで前記容器とは別容器に移すとともに、主としてＣ
ａＯおよびＣａＦ2、主としてＣａＯおよびＡl2Ｏ3、ま
たは主としてＣａＯ，ＣａＦ2およびＡｌ2Ｏ3からなる
いずれかの組合せの造滓剤を添加し、ガスプラズマによ
り加熱して再精錬を行ない、炭素 0.01%以下、硫黄 0.0
05%以下にすることを特徴とするＦｅ−Ｎｉ系合金溶湯
の精錬方法である。第１発明と第２発明は、いずれも予
備精錬の前にＦｅ−Ｎｉ合金を溶解し、できれば予備精
錬の前に一次精錬を行なっておく工程を含む。第１発明
と第２発明の違いは、第１発明が予備精錬を行なう炉と
プラズマ精錬を行なう炉が同一であるのに対し、第２発
明は予備精錬をした溶湯を別の炉に移してプラズマ精錬
を行なう点にある。In a second aspect of the present invention, a molten Fe-Ni alloy containing at least 30 to 50% by weight of Ni, which has been previously melted, is poured into a container having a heating means, and a vacuum or low oxygen content is applied in the container. After pre-smelting to a carbon content of 0.01% or less in a pressure atmosphere, the slag used in the pre-smelting was transferred to a container separate from the above-mentioned container without substantially bringing in the slag.
aO and CaF 2 , predominantly CaO and Al 2 O 3 , or any combination of predominantly CaO, CaF 2 and Al 2 O 3 is added and heated by gas plasma for re-refining, 0.01% or less, sulfur 0.0
This is a refining method for molten Fe-Ni alloys, which is characterized in that the content is made 05% or less. The first invention and the second invention each include a step of melting the Fe-Ni alloy before the pre-refining and, if possible, performing the primary refining before the pre-refining. The difference between the first invention and the second invention is that in the first invention, the furnace for pre-refining and the furnace for plasma refining are the same, whereas in the second invention, the molten metal subjected to pre-refining is transferred to another furnace. The point is to perform plasma refining.
【００１４】また、第３発明は、重量％で少なくともＮ
ｉ 30〜50%を含有するＦｅ−Ｎｉ系の合金を加熱手段を
有する容器中で真空または低酸素分圧雰囲気で、固体原
料から溶解して炭素含有量が0.01%以下まで予備精錬を
した後の溶湯に、主としてＣａＯおよびＣａＦ2、主と
してＣａＯおよびＡl2Ｏ3、または主としてＣａＯ，Ｃ
ａＦ2およびＡｌ2Ｏ3からなるいずれかの組合せの造滓
剤を添加し、ガスプラズマにより加熱して再精錬を行な
い、炭素 0.01%以下、硫黄 0.005%以下にすることを特
徴とするＦｅ−Ｎｉ系合金溶湯の精錬方法である。The third aspect of the invention is to provide at least N by weight%.
After pre-refining a Fe-Ni alloy containing 30 to 50% in a container having a heating means in a vacuum or low oxygen partial pressure atmosphere from a solid raw material to a carbon content of 0.01% or less In the molten metal of CaO and CaF 2 , mainly CaO and Al 2 O 3 , or mainly CaO, C
Fe- characterized by adding a slag-forming agent of any combination consisting of aF 2 and Al 2 O 3 and heating it with a gas plasma for re-refining to make carbon 0.01% or less and sulfur 0.005% or less. This is a refining method for molten Ni-based alloy.
【００１５】第４発明は、重量％で少なくともＮｉ 30
〜50%を含有するＦｅ−Ｎｉ系の合金を加熱手段を有す
る容器中で真空または低酸素分圧雰囲気で、固体原料か
ら溶解して炭素含有量が0.01%以下まで予備精錬をした
後の溶湯を前記容器とは別容器に移すとともに、主とし
てＣａＯおよびＣａＦ2、主としてＣａＯおよびＡl
2Ｏ3、または主としてＣａＯ，ＣａＦ2およびＡｌ2Ｏ3
からなるいずれかの組合せの造滓剤を添加し、ガスプラ
ズマにより加熱して再精錬を行ない、炭素 0.01%以下、
硫黄 0.005%以下にすることを特徴とするＦｅ−Ｎｉ系
合金溶湯の精錬方法である。The fourth invention is to provide at least Ni 30 by weight.
A molten metal after pre-refining an Fe-Ni alloy containing 50% to 50% of carbon content in a container having a heating means in a vacuum or a low oxygen partial pressure atmosphere from a solid raw material to a carbon content of 0.01% or less. Was transferred to a container different from the above-mentioned container, and mainly CaO and CaF 2 , mainly CaO and Al
2 O 3 , or mainly CaO, CaF 2 and Al 2 O 3
Add a slag forming agent in any combination consisting of, and perform refining by heating with gas plasma, carbon 0.01% or less,
A method for refining a molten Fe-Ni alloy is characterized in that the content of sulfur is 0.005% or less.
【００１６】本発明は、Ｎｉ 30〜50%を含有するＦｅ−
Ｎｉ系合金の溶湯を、プラズマ精錬に移行する直前まで
に、炭素を0.01%以下に下げておき、プラズマ精錬過程
では炭素の変動を極少としてスカムなど不純物の除去、
脱硫を中心にした精錬に専念できることに特徴がある。
そのため、本発明の特徴は、特定条件下でのＦｅ−Ｎｉ
系合金の予備精錬を行ない、引き続いて新しく添加する
特定の造滓剤を用いてガスプラズマによる再精錬を行な
うところにある。The present invention is based on Fe-containing 30 to 50% Ni.
The carbon content of the molten Ni-based alloy is reduced to 0.01% or less just before the plasma refining, and the fluctuation of carbon is minimized during the plasma refining process to remove impurities such as scum.
It is characterized by being able to concentrate on refining centered on desulfurization.
Therefore, the feature of the present invention is that Fe-Ni under specific conditions is used.
Pre-refining of system alloys is carried out, and then re-refining by gas plasma is carried out by using a newly added specific slag forming agent.
【００１７】本発明でいう真空または低酸素分圧雰囲気
とは、それぞれ大気圧未満の雰囲気、または大気中の酸
素分圧すなわち213HPa(1013HPa×0.21)未満の酸素分圧
雰囲気を意味する。この条件を満足させる手段として
は、真空ポンプで排気し減圧すること、不活性ガス(Ａ
ｒやＮ2ガス）で酸素の一部を置換すると、または減圧
とガス置換を組み合わせて、数100Torr以下の不活性ガ
ス雰囲気とする方法がある。本発明では、予備精錬過程
で本発明で規定するＦｅ−Ｎｉ系合金の溶湯の炭素含有
量を0.01%以下に調整しておくことが重要である。この
手段としては、まず原料である鉄源の炭素含有量を極力
少ないものを選ぶことが必要で、例えばＣ 0.01%以下を
狙う時は、鉄源のＣ％は0.03%程度が望ましい。The term "vacuum or low oxygen partial pressure atmosphere" as used in the present invention means an atmosphere of less than atmospheric pressure, or an oxygen partial pressure of less than 213 HPa (1013 HPa × 0.21), that is, an oxygen partial pressure in the air. Means for satisfying this condition include exhausting with a vacuum pump to reduce the pressure, and inert gas (A
There is a method of substituting a part of oxygen with r or N 2 gas) or by combining reduced pressure and gas substitution to obtain an inert gas atmosphere of several 100 Torr or less. In the present invention, it is important to adjust the carbon content of the molten Fe-Ni alloy specified in the present invention to 0.01% or less in the preliminary refining process. As a means for this, it is necessary to first select an iron source as a raw material that has as low a carbon content as possible. For example, when aiming for C 0.01% or less, the C% of the iron source is preferably about 0.03%.
【００１８】さらに、低い値、例えばＣ 0.005%程度を
狙う場合は、鉄源のＣ％は0.015〜0.02%程度が望まし
い。しかし、Ｃ％が低い鉄源はコスト高になるので、そ
の場合は鉄鉱石やＮｉＯなどの酸化物による脱炭反応と
組み合わせることができる。さらに、第３の手段として
は、撹拌と組み合わせることができる。撹拌の方法とし
ては、電磁撹拌やＡｒガスによる撹拌が採用できる。こ
れらの手段を兼ね備えた炉として真空誘導炉（ＶＩＦ）
が望ましいが、本発明の予備精錬はＡＯＤ炉、ＶＯＤ炉
などの実用炉でも実現できる。さらに、上記発明の予備
精錬で炭素含有量を0.01%以下に調整する手段を酸素ガ
スなどの酸素源または酸素源と不活性ガスの混合物を添
加または吹き込みとすることができる。この場合は、効
率的な脱酸が可能であり、鉄源の炭素含有量が少々高く
てもよいという利点がある。Further, when aiming at a low value, for example, about C 0.005%, the C% of the iron source is preferably about 0.015 to 0.02%. However, since an iron source with a low C% is expensive, it can be combined with a decarburization reaction with an oxide such as iron ore or NiO. Furthermore, the third means can be combined with stirring. As a stirring method, electromagnetic stirring or stirring with Ar gas can be adopted. A vacuum induction furnace (VIF) as a furnace that combines these means
However, the preliminary refining of the present invention can also be realized in a practical furnace such as an AOD furnace or a VOD furnace. Furthermore, the means for adjusting the carbon content to 0.01% or less in the preliminary refining of the above invention may be addition or blowing of an oxygen source such as oxygen gas or a mixture of an oxygen source and an inert gas. In this case, there is an advantage that efficient deoxidation is possible and the iron source may have a slightly high carbon content.
【００１９】プラズマ精錬で使用する造滓剤は、前記の
ようにＣａＯを必須とし、それにＣａＦ2，Ａｌ2Ｏ3の
１種または２種を添加する新たな合成造滓剤を再精錬で
用いるのが本発明の特徴である。特に予備精錬炉での精
錬用のスラグは再精錬に実質的に持ち込まないところに
本発明の別の特徴がある。新たに添加する造滓剤が「主
として」とは、本発明の新たに添加する造滓剤がスラグ
容量の95%以上のほとんどを占めることを意味するが、
塩基度調整のための極少量のＳｉＯ2などの添加は許容
される。しかし、本発明の方法によれば通常はＳｉＯ2
も予備精錬炉の不純物として持ち込まれるので添加する
必要はない。As the slag forming agent used in the plasma refining, CaO is essential as described above, and a new synthetic slag forming agent to which one or two kinds of CaF 2 and Al 2 O 3 are added is used in the re-refining. That is the feature of the present invention. In particular, the slag for refining in the preliminary refining furnace has another feature of the present invention in that it is not substantially brought into re-refining. The newly added slag forming agent "mainly" means that the newly added slag forming agent occupies most of 95% or more of the slag capacity,
Addition of a very small amount of SiO 2 or the like for adjusting the basicity is allowed. However, according to the method of the present invention, normally SiO 2
Also, since it is brought in as an impurity in the preliminary refining furnace, it is not necessary to add it.
【００２０】本発明において、予備精錬として誘導加熱
方法によるものが望ましい。また、別容器は予備精錬で
のスプラッシュやヒューム等による汚染を受けないよう
に準備するとよい。なお、本願の精錬方法において、再
精錬は、ポーラスプラグ、その他の方法によるガス吹込
み法や誘導法等による撹拌条件下で行なうことが望まし
く、また再精錬容器からの出湯は、容器底に設けたスラ
イディングノズル方式によるものが、傾注法やストッパ
形式のものによるものよりスラグの混入やプラズマ加熱
によるストッパの損傷等の不都合がなく適当である。In the present invention, it is desirable to use the induction heating method as the pre-refining. Moreover, it is advisable to prepare a separate container so that it will not be contaminated by splash or fume in the pre-refining. In the refining method of the present application, the re-refining is preferably performed under stirring conditions such as a porous plug or other method such as a gas blowing method or an induction method, and tapping from the re-refining container is provided at the bottom of the container. The sliding nozzle method is more suitable than the tilting method or the stopper type method because it does not cause inconveniences such as mixing of slag and damage to the stopper due to plasma heating.
【００２１】[0021]
【作用】本発明は、極めて低い炭素、硫黄および非金属
介在物が要求されるＮｉ 30〜50%を含有するＦｅ−Ｎｉ
系合金の新しい精錬方法を提案するもので、その構成は
プラズマ精錬の負荷を大幅に低減する特定条件の予備精
錬とプラズマ精錬の組合せを必須としている。さらに本
発明では、予備精錬での負荷を軽減する目的を主とする
一次精錬との組合せをも含むものである。The present invention is based on Fe-Ni containing 30 to 50% of Ni which requires extremely low carbon, sulfur and non-metallic inclusions.
We propose a new refining method for system alloys, and its composition requires a combination of pre-refining and plasma refining under specific conditions that significantly reduces the load of plasma refining. Further, the present invention also includes a combination with primary refining whose main purpose is to reduce the load in preliminary refining.
【００２２】本発明では、予備精錬過程で炭素を0.01%
以下、Ｆｅ−Ｎｉ合金のエッチング性向上などの厳しい
要求の場合には、望ましくは0.005%以下に下げておく。
この条件を満足させることで次工程のプラズマによる再
精錬過程でＣ％を0.01%、望ましくは0.005%以下のまま
推移させ、最終製品の炭素含有量を少なくとも0.01%以
下にすることができるのである。このことは、再精錬過
程で脱炭をする工程をほとんどなくすか、極めて少量の
脱炭を行なえばよい程度となり、全体の精錬時間を短縮
化するとともに、プラズマ再精錬では脱炭以外の精錬を
主に行ない、極めて低い不純物と低ＣのＦｅ−Ｎｉ合金
が得られるものである。In the present invention, 0.01% of carbon is added in the preliminary refining process.
Hereafter, in the case of strict requirements for improving the etching property of the Fe-Ni alloy, it is preferably lowered to 0.005% or less.
By satisfying this condition, it is possible to keep C% at 0.01%, preferably 0.005% or less in the re-refining process by the plasma in the next step, and make the carbon content of the final product at least 0.01% or less. . This means that the process of decarburization in the re-refining process can be almost eliminated or an extremely small amount of decarburization can be performed, shortening the overall refining time, and plasma rerefining requires refining other than decarburization. This is mainly carried out to obtain an Fe-Ni alloy with extremely low impurities and low C.
【００２３】本発明の精錬方法において予備精錬は、加
熱手段を有する容器中で行なわれるから、多岐に亘る材
質や要求精錬レベルに対しても、比較的少量の溶湯に対
しても、要すれば加熱手段を用いることにより、溶湯の
温度低下が防止され、これにより柔軟に対応して所定の
精錬レベルの溶湯を得ることができる。本発明では、第
１、第２発明のように予備精錬に先立つ溶解・精錬炉と
してアーク炉を用いれば溶解と精錬が効率よく行なえ、
特に炭素含有量の高い鉄源を用いたＦｅ−Ｎｉ合金の精
錬の場合には、アーク炉での酸素吹錬も併用できるなど
の利点がある。このため、予備精錬炉の負担が軽減され
る効果がある。本発明の第３、第４発明のように予備精
錬炉で固体原料の溶解から実施する場合には、当然一次
精錬炉を省略できるし、真空または減圧下での速やかな
脱炭ができる。In the refining method of the present invention, the pre-refining is carried out in a container having a heating means, so that it is possible to use a wide variety of materials, required refining levels, and a relatively small amount of molten metal, if necessary. By using the heating means, it is possible to prevent the temperature of the molten metal from lowering, so that it is possible to flexibly obtain the molten metal having a predetermined refining level. In the present invention, if an arc furnace is used as the melting and refining furnace prior to the pre-refining as in the first and second inventions, the melting and refining can be performed efficiently.
Particularly, in the case of refining an Fe-Ni alloy using an iron source having a high carbon content, there is an advantage that oxygen blowing in an arc furnace can be used together. Therefore, the burden on the preliminary refining furnace is reduced. When carrying out from the melting of the solid raw material in the preliminary refining furnace as in the third and fourth inventions of the present invention, the primary refining furnace can naturally be omitted, and rapid decarburization can be performed under vacuum or reduced pressure.
【００２４】また、本発明の方法において、再精錬炉で
の精錬効果を上げるために、および予備精錬での耐火物
との反応生成物を減らすために、耐火物の選択が重要で
ある。すなわち予備精錬は基本的に減圧下で行なうた
め、ＳｉＯ2含有量の多い耐火物は不向きであり、高ア
ルミナ質、またはマグネシア系の塩基性レンガを使用す
るか、超高温で焼成したマグクロ系ダイレクトボイドレ
ンガの使用が有効である。また、予備精錬開始前の耐火
物の保熱も重要であり、これらの配慮をして初めてスカ
ムの量が減少し、再精錬でのＣａＯを必須とする造滓剤
の役割が生かせるのである。また、第２発明の精錬方法
において、再精錬は、予備精錬とは別の新鮮な容器中で
行なわれるから、造滓剤の添加によるスラグの汚染は寡
少で、高レベルに精錬された溶湯が容易に、かつ効率的
に得られる。In the method of the present invention, the selection of refractory materials is important in order to enhance the refining effect in the re-refining furnace and to reduce the reaction products with the refractory materials in the pre-refining. That is, since pre-smelting is basically performed under reduced pressure, refractories with a high SiO 2 content are not suitable, and high alumina-based or magnesia-based basic bricks are used, or magkuro-based direct bricks fired at ultra-high temperatures are used. Use of void brick is effective. In addition, it is important to retain heat of the refractory before the start of preliminary refining, and the amount of scum is reduced only after taking these considerations into consideration, and the role of the slag forming agent that requires CaO in re-refining can be utilized. Further, in the refining method of the second invention, the re-refining is performed in a fresh container different from the preliminary refining, so that the slag is hardly contaminated by the addition of the slag-forming agent, and the molten metal refined to a high level is Obtained easily and efficiently.
【００２５】本発明の方法は、予備精錬段階で造滓剤を
添加しないので、実質的にスラグの発生がなく、蒸発で
きない不純物やスカム状の不純物は次工程の再精錬で新
たに添加する造滓剤をガスプラズマ加熱により活性化さ
せて効果的に吸収させることにより行なわれる。すなわ
ち、本発明において、造滓剤はガスプラズマ加熱により
十分加熱されて低粘性かつ活性化されることにより、前
記付着物、浮遊物等の不純物の再混入物質および非金属
介在物ならびに耐火物に起因する汚染物質を効果的に捕
集することができ、望ましくは後述の不活性ガス吹込み
等による十分な撹拌により、溶湯と十分に相互に交換し
つつ接触し、高い精錬効果を生ずる。In the method of the present invention, since the slag-forming agent is not added in the pre-refining stage, substantially no slag is generated, and impurities that cannot be evaporated or scum-like impurities are newly added in the re-refining in the next step. It is carried out by activating the slag agent by gas plasma heating to effectively absorb the slag agent. That is, in the present invention, the slag-forming agent is sufficiently heated by gas plasma heating to be low-viscosity and activated, so that the re-mixed substances of impurities such as the deposits and suspended matter, non-metallic inclusions, and refractories can be obtained. The resulting pollutants can be effectively collected, and desirably, sufficient agitation such as by injecting an inert gas, which will be described later, sufficiently contacts with the molten metal while exchanging them with each other, resulting in a high refining effect.
【００２６】再精錬で使用する造滓剤には、脱酸と脱硫
効果の高いＣａＯを必須とし、流動性を高めて精錬効果
を向上させる目的で低融点のＣａＦ2と、脱酸効果およ
び脱硫性改善の目的でＡｌ2Ｏ3を適宜組み合わせたもの
を主に添加する。この際、塩基度を調整するためのＳｉ
Ｏ2は、添加せずとも、予備精錬時に不純物として混入
するＳｉＯ2と新たに添加する上記のＣａＯによって塩
基度2以上に調整する。望ましい塩基度は3〜7である。
造滓剤はまとめて溶湯に入れるが、例えば上記のＡｒを
利用して炉底から吹き込んで添加することができる。CaO, which has a high deoxidizing and desulfurizing effect, is essential for the slag forming agent used in the re-refining, and CaF 2 having a low melting point, a deoxidizing effect and a desulfurizing effect are used for the purpose of enhancing fluidity and improving the refining effect. A suitable combination of Al 2 O 3 is mainly added for the purpose of improving the properties. At this time, Si for adjusting the basicity
Even if O 2 is not added, it is adjusted to have a basicity of 2 or more by SiO 2 which is mixed as an impurity in the pre-refining and CaO which is newly added. A desirable basicity is 3-7.
The slag forming agent is put into the molten metal as a whole, but it can be added by blowing it from the bottom of the furnace using the above Ar.
【００２７】再精錬での加熱は本発明ではガスプラズマ
加熱法であるのが特徴である。このように再精錬を行な
うガスプラズマ加熱法は、上述のようにＣａＯおよびＣ
ａＦ2、ＣａＯおよびＡl2Ｏ3、またはＣａＯ，ＣａＦ2
およびＡｌ2Ｏ3からなるいずれかの合成造滓剤を効果的
に加熱する一方、溶湯や造滓剤の表面を被覆して溶湯の
酸化や造滓剤が酸化性となることを防ぎつつ、溶湯を昇
温し、または温度低下を補償し、かつ、黒鉛電極アーク
加熱法のごとく、炭素のピックアップ等の再汚染の危険
がないので本発明が対象とする低Ｃ（Ｃ≦0.01%)のＦｅ
−Ｎｉ系合金の精錬には都合がよい。なお、本発明方法
では、後述の実施例のように予備精錬以上の高レベルに
まで精錬を行なうものを含んでも良いことは言うまでも
ない。The heating in the re-refining is characterized by the gas plasma heating method in the present invention. The gas plasma heating method in which refining is performed as described above is performed by using CaO and C as described above.
aF 2 , CaO and Al 2 O 3 , or CaO, CaF 2
While effectively heating any synthetic slag-forming agent consisting of Al 2 O 3 and Al 2 O 3, while coating the surface of the molten metal or the slag-forming agent to prevent oxidation of the molten metal or oxidization of the slag-forming agent, Since the temperature of the molten metal is raised or the temperature is reduced, and there is no risk of recontamination such as carbon pickup as in the graphite electrode arc heating method, low C (C ≦ 0.01%) which is the object of the present invention. Fe
-Convenient for refining Ni-based alloys. It is needless to say that the method of the present invention may include refining to a higher level than the pre-refining as in Examples described later.
【００２８】なお、プラズマ加熱下で行なう再精錬前の
予備精錬終了時点の溶湯が実質的にスラグのないものと
は、予備精錬を行なう目的で造滓剤を添加して十分な反
応を終えて発生したスラグがないことを指す。したがっ
て、本発明のうちの第２発明や第４発明において、別容
器の再精錬に注湯する前の予備精錬終了直前、または終
了直後の溶湯に造滓剤を添加して再精錬炉に注湯するこ
とがあるが、これは予備精錬炉中で造滓剤の添加による
精錬を目的としたものではないので、予備精錬での反応
用のスラグはないものと実質的に同一であり、予備精錬
時のスラグを次の再精錬炉に実質的に持ち込まないとす
る本発明方法に包含されるものである。本発明の精錬方
法における望ましい態様である撹拌の方法は、炉底に設
けたポーラスプラグからの不活性ガスによるものが、撹
拌効果の点から望ましい。不活性ガスを吹き込む時に本
発明で使用する種類の造滓剤を粉末の形で吹き込むこと
も、造滓剤による介在物の捕捉の点から有効である。ま
た、電磁撹拌装置を単独またはガス吹き込みと併用して
用いてもよい。The molten metal at the end of the pre-refining before plasma refining is substantially slag-free, meaning that a slag-forming agent is added for the purpose of pre-refining to complete the reaction. It means that there is no slag that has occurred. Therefore, in the second invention and the fourth invention of the present invention, the smelting agent is added to the molten metal immediately before or after the completion of the pre-smelting before pouring the molten metal for re-smelting in another container, and the molten metal is poured into the re-smelting furnace. Although it may be hot water, this is not intended for refining by adding a slag forming agent in the pre-smelting furnace, so it is substantially the same as the one without slag for reaction in the pre-smelting. It is included in the method of the present invention in which the slag at the time of refining is not substantially brought into the subsequent re-refining furnace. As the stirring method, which is a desirable mode in the refining method of the present invention, it is preferable to use an inert gas from a porous plug provided at the bottom of the furnace from the viewpoint of the stirring effect. Blowing a slag-forming agent of the type used in the present invention in the form of powder when blowing an inert gas is also effective from the viewpoint of capturing inclusions by the slag-forming agent. The electromagnetic stirring device may be used alone or in combination with gas blowing.
【００２９】ガスプラズマ加熱装置は、前述のようにバ
ーナのごとく、ＣＯ2、Ｈ2Ｏ、遊離Ｏ2等の酸化性ガス
を発生せず、かつ高温加熱に適する。また、本発明では
ＣａＯ，ＣａＦ2，Ａｌ2Ｏ3などの造滓剤を第１発明や
第３発明では、予備精錬炉に引き続き添加して精錬し、
第２発明や第４発明では再精錬炉に移した後で添加する
から、迅速に加熱して流動性のあるスラグとし、できる
だけ早期に溶湯と接触させて脱酸や脱硫反応を促進させ
る必要がある。そのためにも本発明の方法であるガスプ
ラズマ加熱装置は有効である。さらに前記の加熱装置
は、黒鉛電極による加熱のように炭素の変動がないとい
う効果がある。この効果は極めて炭素の制御が要求され
る本発明が対象とする、重量％で少なくともＮｉ 30〜5
0%を含有するＦｅ−Ｎｉ系合金に適している。The gas plasma heating apparatus does not generate an oxidizing gas such as CO 2 , H 2 O and free O 2 like the burner as described above, and is suitable for high temperature heating. Further, in the present invention, slag-refining agents such as CaO, CaF 2 , Al 2 O 3 and the like in the first invention and the third invention are added to the preliminary refining furnace successively for refining,
In the second invention and the fourth invention, since it is added after being transferred to the re-refining furnace, it is necessary to rapidly heat it to form a fluid slag, and to bring it into contact with the molten metal as early as possible to accelerate the deoxidation or desulfurization reaction. is there. For that purpose, the gas plasma heating apparatus which is the method of the present invention is effective. Further, the above-mentioned heating device has an effect that carbon does not fluctuate unlike heating by a graphite electrode. This effect is aimed at by the present invention in which extremely high carbon control is required.
Suitable for Fe-Ni alloys containing 0%.
【００３０】[0030]
（実施例１）図１に示す設備において、以下に示す手順
で操業を行なった。誘導加熱精錬炉５でＦｅ−Ｎｉ合金
のスクラップ、鉄源、Ｎｉ源からなる固体原料を溶解し
た。目標とする組成は、Ｆｅ−42Ｎｉ合金で、Ｃ％が0.
008以下、Ｓ％が0.005以下である。鉄源のＣ％は0.034
であり、合金原料と脱炭を兼ねた固体原料としてＮｉＯ
（酸化ニッケル）と鉄鉱石をトン当り12kg/tonで使用し
た。真空排気系６ａにより、大気遮断室ａ内を真空にし
て一部ＮｉＯの添加で合金組成を調整しながら脱炭と脱
酸を繰返し予備精錬を行なった。本実施例では固体原料
から予備精錬炉で開始しているが、この固体原料の溶解
を別の炉で行ない、図１に示す予備精錬炉５に取鍋を介
して蓋体３を開放して溶湯を移すことでも実施できる。(Example 1) The equipment shown in FIG. 1 was operated in the following procedure. In the induction heating and refining furnace 5, a solid raw material composed of Fe—Ni alloy scrap, an iron source, and a Ni source was melted. The target composition is Fe-42Ni alloy with C% of 0.
008 or less and S% is 0.005 or less. C% of iron source is 0.034
NiO as a solid raw material that also serves as an alloy raw material and decarburization
(Nickel oxide) and iron ore were used at 12 kg / ton per ton. Preliminary refining was performed by repeating decarburization and deoxidation while adjusting the alloy composition by partially adding NiO by evacuating the atmosphere shut-off chamber a by the vacuum exhaust system 6a. In this embodiment, the solid raw material is started in the preliminary refining furnace, but the solid raw material is melted in another furnace, and the lid 3 is opened through the ladle in the preliminary refining furnace 5 shown in FIG. It can also be carried out by transferring the molten metal.
【００３１】並行的に大気遮断室ａの内部には、予め予
熱された再精錬容器が容器蓋体２７ａを付けてセットさ
れている。これは予備精錬中のスプラッシュなどを防止
するためである。本実施例では、再精錬容器２７′を大
気遮断室ａの内部に予めセットしたが、ａとは別の大気
遮断室（図示しないがｂとする）を仕切りバルブ４を介
して連通して設ければ、外段取りで再精錬容器２７′を
準備することができる。この場合には、プラズマ加熱に
よる再精錬位置２７でプラズマの予熱を利用して再精錬
容器を十分予熱しておくことができる。その後、予備精
錬が終了する直前からａ室と連通する大気遮断室ｂをａ
室と同程度以上の減圧状態にして、仕切りバルブ４を開
放して再精錬容器２７′を２７の位置から２７′の位置
に移動する。その後は、本実施例と同様に予備精錬の終
了した溶湯を受湯して再び再精錬位置２７に移動する。In parallel, a re-refining container preheated in advance is set inside the atmosphere shut-off chamber a with a container lid 27a. This is to prevent splashing during pre-refining. In the present embodiment, the re-refining vessel 27 'is preset inside the air shut-off chamber a, but an air shut-off chamber (not shown in the figure, denoted by b) different from a is provided in communication via the partition valve 4. Then, the re-refining container 27 'can be prepared by an external setup. In this case, the re-refining vessel can be sufficiently pre-heated by utilizing the pre-heating of plasma at the re-refining position 27 by plasma heating. After that, immediately before the completion of the pre-refining, the atmosphere shut-off chamber b communicating with the chamber a is opened.
The pressure is reduced to the same level as the chamber or higher, and the partition valve 4 is opened to move the re-refining vessel 27 'from the position 27 to the position 27'. After that, similarly to the present embodiment, the molten metal which has been subjected to the pre-refining is received and moved to the re-refining position 27 again.
【００３２】この方法は、再精錬容器にスプラッシュな
どが付着することが防止できること、十分な予熱がで
き、速やかにプラズマ精錬の効果が発揮できる特徴があ
る。大気遮断室ａでの精錬が完了すると、誘導加熱精錬
炉５を傾動することにより、溶湯を再精錬容器２７′へ
出湯する。次に仕切バルブ４を開放し、その開口を経て
再精錬容器２７′を軌条および台車２４により再精錬位
置２７へ移動した。続いて副原料投入系９により造滓剤
を添加し、ガスプラズマ加熱装置により加熱して造滓剤
の溶融、加熱を行ない、かつ不活性ガス導入系７ｂを経
てポーラスプラグ２８からＡｒガス吹込み撹拌すること
により、再精錬を行なった。再精錬が終了し、所定の鎮
静を行なった後、スライディングノズル２９を経てイン
ゴットケース３０に鋳造した。This method is characterized in that splash and the like can be prevented from adhering to the re-refining vessel, sufficient preheating can be performed, and the effect of plasma refining can be promptly exhibited. When the refining in the atmosphere shut-off chamber a is completed, the induction heating refining furnace 5 is tilted to discharge the molten metal into the re-refining vessel 27 '. Next, the partition valve 4 was opened, and the re-refining vessel 27 ′ was moved to the re-refining position 27 by the rail and the carriage 24 through the opening. Subsequently, a slag forming agent is added by the auxiliary raw material charging system 9 and heated by a gas plasma heating device to melt and heat the slag forming agent, and Ar gas is blown from the porous plug 28 through the inert gas introducing system 7b. Re-refining was performed by stirring. After the re-refining was completed and a predetermined sedation was performed, it was cast into the ingot case 30 through the sliding nozzle 29.
【００３３】次に本願の方法発明の効果を各種のテスト
例で説明する。いずれも、実験に用いた溶湯は、Ｆｅ−
42Ｎｉ合金である。図２は、アーク炉で溶解し、特に脱
炭処理をしない状態で真空誘導加熱精錬炉に受湯して、
引き続き前記精錬炉を真空にして予備精錬をした時の経
過時間に対する精錬の進行度合を、鋼中のＯ値，Ｃ値お
よびＳ値で測定した結果を示した図である。図２から、
真空精錬により経過時間とともに、溶湯中の酸素が気化
する際に炭素と反応してＣＯガスとなって精錬炉外に排
出される結果、脱酸とともに脱炭も急速に進行する反
面、脱硫は進行しないことがわかる。Next, the effects of the method invention of the present application will be described with various test examples. In each case, the molten metal used in the experiment was Fe-
42Ni alloy. Figure 2 shows that it melts in an arc furnace and receives hot water in a vacuum induction heating and refining furnace without decarburization.
It is the figure which showed the result of having measured the progress degree of refining with respect to the elapsed time at the time of preliminarily refining the said refining furnace in vacuum, by measuring the O value, C value, and S value in steel. From FIG.
Over time with vacuum refining, when oxygen in the melt vaporizes, it reacts with carbon and becomes CO gas, which is discharged outside the refining furnace. As a result, decarburization and decarburization proceed rapidly, but desulfurization progresses. I know I won't.
【００３４】図３は、アーク炉で溶解し、真空誘導炉
（ＶＩＦ）で予備精錬したＦｅ−Ｎｉ合金の溶湯を、別
の容器に注湯し、予めガスプラズマ加熱装置で内張り耐
火物を加熱した再精錬容器へ上述と同一条件の傾注によ
り受湯し、造滓剤を添加すると共に、炉底のポーラスプ
ラグによるアルゴンガス撹拌と溶湯上面からのガスプラ
ズマ加熱を行ないつつ、本発明における再精錬を行なっ
た時のＯ値、Ｓ値、Ｃ値の変化を示すものである。な
お、再精錬時に添加した造滓剤は、ＣａＯとＣａＦ2と
Ａｌ2Ｏ3を２対１対１の比率で溶湯トン当り合計で２０
ｋｇであった。図３から、本発明に係る再精錬で再混入
物の再溶解は防止され、時間の経過とともに脱硫が進行
し、また酸素濃度も徐々に低下していることがわかる。
なお、この精錬で得られた合金をＪＩＳ法で非金属介在
物の評価を行なったが、下記に示すＡＳＥＡ−ＳＫＦ炉
での再精錬の場合は、ｄ60×400＝0.025%であったもの
が、ｄ60×400＝0.004%と減少し、非金属介在物低減の
効果も大きいことを確認した。FIG. 3 shows that a molten Fe-Ni alloy melted in an arc furnace and preliminarily refined in a vacuum induction furnace (VIF) is poured into another container, and the refractory lining is heated in advance by a gas plasma heating device. While refining according to the present invention while receiving hot water by decanting under the same conditions as described above to the re-refining container, adding the slag forming agent, stirring argon gas with a porous plug at the furnace bottom, and performing gas plasma heating from the upper surface of the molten metal. It shows changes in O value, S value, and C value when performing. The slag-forming agent added during re-refining was 20% in total per ton of molten metal at a ratio of CaO, CaF 2 and Al 2 O 3 of 2: 1: 1.
It was kg. It can be seen from FIG. 3 that re-melting of the re-mixture is prevented by the re-refining according to the present invention, the desulfurization progresses over time, and the oxygen concentration gradually decreases.
The non-metallic inclusions of the alloy obtained by this refining were evaluated by the JIS method. In the case of re-refining in the ASEA-SKF furnace shown below, d 60 × 400 = 0.025% However, it was confirmed that d 60 × 400 = 0.004%, and the effect of reducing non-metallic inclusions is also large.
【００３５】一方、図４は前記の実施例と同様なアーク
炉と真空誘導炉（ＶＩＦ）を用いた予備精錬を行なった
溶湯を従来実施された精錬のうちの一つであるＡＳＥＡ
−ＳＫＦ炉に注湯して再精錬を行なった時の経過時間に
対するＯ値、Ｓ値、Ｃ値の変化を示したものである。図
４から、従来のＡＳＥＡ−ＳＫＦ炉による精錬は、脱
酸、脱硫に対して有効であるが、加熱電極が黒鉛製のた
め炭素のピックアップにより急激にＣ値が増加してお
り、炭素の混入が厳しく制限される本発明が対象とする
Ｆｅ−42Ｎｉ合金には不適当であることがわかる。On the other hand, FIG. 4 shows one of the conventional refinements of molten metal which has been subjected to preliminary refining using an arc furnace and a vacuum induction furnace (VIF) similar to the above-mentioned embodiment.
-It shows changes in O value, S value, and C value with respect to the elapsed time when the molten metal was poured into the SKF furnace and refining was performed. From FIG. 4, the refining by the conventional ASEA-SKF furnace is effective for deoxidation and desulfurization, but since the heating electrode is made of graphite, the C value is rapidly increased by the pickup of carbon, and the mixing of carbon It is found that the present invention is unsuitable for the Fe-42Ni alloy targeted by the present invention, in which
【００３６】（実施例２）図５に示す設備を用いて、以
下に示す手順で操業を行なった。実施例１と同じＦｅ−
42Ｎｉ合金の固体原料を容器５０内に投入した後、容器
真空蓋５３を施し、真空排気系５４により容器５０内を
減圧し、誘導加熱コイル５２により溶解を開始した。次
いで溶解した溶湯に図示しないランスをこの溶湯５１に
挿入し、前記ランスを介して外部から酸素ガスとＡｒガ
スを混合したガスを吹き込んで脱炭精錬を行なった。上
記の混合ガスの吹き込みを終了した後に、引き続いて酸
化ニッケルと酸化鉄（Ｆｅ2Ｏ3）を合計で溶湯トン当り
３ｋｇ投入装置５５から添加した。次に真空排気系５４
の容量を高めて脱酸を開始した。脱酸精錬が終了した時
点で溶湯サンプルを採取した結果、Ｏ値が66ppm、Ｃ値
が27ppm、Ｓ値が83ppmであった。続いて真空排気系５４
を止め、アルゴン底吹き撹拌装置５８からアルゴンガス
を流入して置換した。(Example 2) Using the equipment shown in FIG. 5, operation was performed in the following procedure. Fe-same as in Example 1
After the solid raw material of 42Ni alloy was charged into the container 50, the container vacuum lid 53 was provided, the pressure inside the container 50 was reduced by the vacuum exhaust system 54, and the melting was started by the induction heating coil 52. Next, a lance (not shown) was inserted into the melted melt, and a mixed gas of oxygen gas and Ar gas was blown from the outside through the lance to perform decarburization refining. After the blowing of the mixed gas was completed, subsequently, nickel oxide and iron oxide (Fe 2 O 3 ) were added in total from a 3 kg charging device 55 per ton of molten metal. Next, the vacuum exhaust system 54
The capacity was increased to start deoxidation. As a result of collecting a molten metal sample when the deoxidation refining was completed, the O value was 66 ppm, the C value was 27 ppm, and the S value was 83 ppm. Then, the vacuum exhaust system 54
Then, the argon gas was introduced from the bottom-blown stirrer 58 to replace the gas.
【００３７】次いで投入装置５５からＣａＯとＣａＦ2
を１対１の比率で、溶湯トン当り合計で２０ｋｇの造滓
剤を添加した。次いで、容器真空蓋５３の外部にセット
してあるプラズマ加熱トーチ５６を容器５０内に挿入し
てプラズマ加熱を開始し、同時に前記アルゴン底吹き撹
拌装置５８からアルゴンガスを吹き込みながら、溶湯を
撹拌させて再精錬を行なった。再精錬が終了すると、ス
ライディングノズル５７を開口し、前記スライディング
ノズルの下に用意されたインゴットケースに受湯した。
このようにして得られた鋳塊から採取した試料を分析し
た結果、実施例１の真空精錬によって脱炭、脱酸し、さ
らにブラズマ加熱炉で再精錬した合金のＯ値が36ppm、
Ｃ値が54ppm、Ｓ値が65ppmであったのに対して、上記方
法による合金は、Ｏ値が31ppm、Ｃ値は27ppm、Ｓ値が32
ppmであった。Then, CaO and CaF 2 are fed from the charging device 55.
Was added in a ratio of 1: 1 in total of 20 kg of slag forming agent per ton of molten metal. Next, the plasma heating torch 56 set outside the container vacuum lid 53 is inserted into the container 50 to start plasma heating, and at the same time, the molten metal is stirred while the argon gas is blown from the argon bottom blowing stirring device 58. And refined it. When the re-refining was completed, the sliding nozzle 57 was opened, and hot water was received in the ingot case prepared under the sliding nozzle.
As a result of analyzing the sample collected from the ingot thus obtained, the O value of the alloy decarburized and deoxidized by the vacuum refining of Example 1 and further refined in the plasma heating furnace was 36 ppm,
While the C value was 54 ppm and the S value was 65 ppm, the alloy by the above method had an O value of 31 ppm, a C value of 27 ppm and an S value of 32 ppm.
It was ppm.
【００３８】なお、以上の実施例において、予備精錬の
例として真空精錬法を用いた例で述べたが、本発明はこ
れに限定されない。すなわち、精錬対象である溶湯が含
有する合金成分元素によっては、その成分の蒸発等によ
る損失を防止抑制するため、通常、絶対圧力で200Torr
程度以下の不活性ガス雰囲気が適宜選定されており、高
真空でない場合も本発明に含む。次に、図５に示す設備
を用いて上記の実施例２と同じ要領でＦｅ−42Ｎｉ合金
を溶解、脱炭および真空処理による予備精錬を行なった
後、ＣａＯとＡｌ2Ｏ3を１対２の比率で、溶湯トン当り
5kgの造滓剤を添加してプラズマ加熱による再精錬を行
なった。得られた鋳塊から試料を採取して分析した結
果、Ｏ値が49ppm、Ｃ値が31ppm、Ｓ値が51ppmであっ
た。Although the vacuum refining method is used as an example of the pre-refining in the above embodiments, the present invention is not limited to this. In other words, depending on the alloy component elements contained in the molten metal that is the object of refining, in order to prevent loss due to evaporation of the components, it is usually 200 Torr at absolute pressure.
An inert gas atmosphere of a certain degree or less is appropriately selected, and the present invention includes the case where the vacuum is not high. Next, after the Fe-42Ni alloy was melted, decarburized, and pre-refined by vacuum treatment in the same manner as in Example 2 using the equipment shown in FIG. 5, CaO and Al 2 O 3 were mixed in a ratio of 1: 2. Per ton of molten metal at a ratio of
Re-refining by plasma heating was carried out by adding 5 kg of slag forming agent. As a result of collecting and analyzing a sample from the obtained ingot, the O value was 49 ppm, the C value was 31 ppm, and the S value was 51 ppm.
【００３９】[0039]
【発明の効果】本発明のＮｉ 30〜50%を含有するＦｅ−
Ｎｉ系合金の精錬方法は、予備精錬炉で予めＣ%を0.01
以下として、かつ予備精錬過程で造滓剤を添加しないの
で、実質的にスラグのない比較的きれいな状態で低Ｃの
ままで再精錬を行ない、予備精錬よりもさらに低い不純
物とすることができる利点がある。再精錬時に添加する
造滓剤は、持込みスラグを改質する必要がないため少量
ですみ、ガスプラズマ加熱により十分加熱されて低粘性
かつ活性化されることにより、効果的、かつ効率良く脱
硫やスカムなどの不純物を除去する再精錬を実施するこ
とができるのである。Effect of the invention Fe-containing 30 to 50% of Ni of the present invention
The refining method for Ni-based alloys is carried out in a preliminary refining furnace with a C% of 0.01
As below, and since no slag forming agent is added in the pre-refining process, it is possible to re-refining with a low C content in a relatively clean state with substantially no slag, and to obtain impurities lower than in the pre-refining There is. The amount of slag addition agent added during re-smelting does not need to be modified to bring in slag, so only a small amount is required.Because it is sufficiently heated by gas plasma heating to have low viscosity and activation, it is possible to perform desulfurization effectively and efficiently. Re-refining to remove impurities such as scum can be carried out.
【００４０】本発明の精錬方法によれば、製品の炭素含
有量と硫黄含有量、および非金属介在物がともに厳しく
制限される、重量％で少なくともＮｉ 30〜50%を含有す
るＦｅ−Ｎｉ系合金の精錬時に、前述の炭素のピックア
ップの問題がなく、持込みスラグを改質する必要もな
く、高レベルの精錬等の場合にも柔軟に対応できる溶湯
の精錬が可能である。また、予備精錬の前段階に一次精
錬とを組み合わせれば、さらに効率のよい精錬ができ
る。According to the refining method of the present invention, the carbon content and the sulfur content of the product and the non-metallic inclusions are strictly limited, and the Fe-Ni system containing at least 30 to 50% by weight of Ni is used. During the refining of the alloy, there is no problem of the above-mentioned carbon pickup, there is no need to modify the carry-in slag, and the refining of the molten metal is possible even in the case of high-level refining. In addition, if the primary refining is combined with the preliminary refining, the refining can be performed more efficiently.
【図１】本発明の実施例に用いた装置の一例を示す図で
ある。FIG. 1 is a diagram showing an example of an apparatus used in an example of the present invention.
【図２】アーク炉で１次精錬した溶湯を真空誘導炉で予
備精錬した時の、精錬経過時間に対する精錬の進行度合
を鋼中の酸素濃度で示した図である。FIG. 2 is a diagram showing the degree of refining progress with respect to the refining elapsed time when the molten metal is first refined in an arc furnace and is pre-refined in a vacuum induction furnace, as an oxygen concentration in steel.
【図３】上記予備精錬（図２）後、本発明のＣａＯ、Ｃ
ａＦ2およびＡｌ2Ｏ3よりなる造滓剤にて、プラズマ再
精錬を行った時の時間経過と溶湯中のＯ値、Ｃ値、Ｓ値
の変化を示す図である。[Fig. 3] CaO, C of the present invention after the above pre-refining (Fig. 2)
aF at 2 and Al 2 O 3 than become slag agents, O value of the time elapsed and the melt when subjected to plasma re refining, C value is a graph showing changes in S value.
【図４】従来方法である真空精錬後の溶湯をＡＳＥＡ−
ＳＫＦ炉で再精錬を行なったＦｅ−42Ｎｉ合金の経過時
間とＯ値、Ｃ値、Ｓ値の変化を示す図である。[FIG. 4] The molten metal after vacuum refining which is a conventional method is ASEA-
It is a figure which shows the elapsed time and the change of O value, C value, and S value of the Fe-42Ni alloy which re-refined in the SKF furnace.
【図５】本発明の実施例に用いた装置の一例を示す図で
ある。FIG. 5 is a diagram showing an example of an apparatus used in the examples of the present invention.
１ 真空または低酸素分圧下精錬装置、２ 大気遮断室
本体、３ 蓋体、４仕切りバルブ、５ 誘導加熱精錬
炉、６ａ 真空排気系、７ａ 不活性ガス導入系、７ｂ
不活性ガス導入系、８ 副原料投入系、９ 副原料投
入系、２０ 再精錬装置、２３ ガスプラズマ加熱装
置、２４ 軌条および台車、２７ 再精錬容器（再精錬
位置）、２７ａ 蓋体、２８ ポーラスプラグ、２９
スライディングノズル、３０ インゴットケース、３１
台車、５０ 容器、５１ 溶湯、５２ 誘導加熱コイ
ル、５３ 容器真空蓋、５４ 真空排気系、５５ 投入
装置、５６ プラズマ加熱トーチ、５７ スライディン
グノズル、５８ アルゴン底吹き撹拌装置、ａ 大気遮
断室1 vacuum or low oxygen partial pressure refining device, 2 atmosphere shut-off chamber body, 3 lid, 4 partition valve, 5 induction heating refining furnace, 6a vacuum exhaust system, 7a inert gas introduction system, 7b
Inert gas introduction system, 8 auxiliary raw material feeding system, 9 auxiliary raw material feeding system, 20 re-refining device, 23 gas plasma heating device, 24 rail and carriage, 27 re-refining container (re-refining position), 27a lid, 28 porous Plug, 29
Sliding nozzle, 30 ingot case, 31
Cart, 50 container, 51 molten metal, 52 induction heating coil, 53 container vacuum lid, 54 vacuum exhaust system, 55 charging device, 56 plasma heating torch, 57 sliding nozzle, 58 argon bottom blowing stirring device, a atmosphere shut-off chamber
Claims (5)
30〜50%を含有するＦｅ−Ｎｉ系合金の溶湯を加熱手段
を有する容器へ注湯し、該容器中で真空または低酸素分
圧雰囲気で、炭素含有量が0.01%以下まで予備精錬をし
た後の溶湯に、主としてＣａＯおよびＣａＦ2、主とし
てＣａＯおよびＡl2Ｏ3、または主としてＣａＯ，Ｃａ
Ｆ2およびＡｌ2Ｏ3からなるいずれかの組合せの造滓剤
を添加し、ガスプラズマにより加熱して再精錬を行な
い、炭素 0.01%以下、硫黄 0.005%以下にすることを特
徴とするＦｅ−Ｎｉ系合金溶湯の精錬方法。1. Pre-dissolved, at least Ni in wt%
A molten Fe-Ni alloy containing 30 to 50% was poured into a container having a heating means, and pre-refined to a carbon content of 0.01% or less in a vacuum or low oxygen partial pressure atmosphere in the container. In the latter molten metal, mainly CaO and CaF 2 , mainly CaO and Al 2 O 3 , or mainly CaO, Ca
Fe-characterized by adding a slag-forming agent in any combination of F 2 and Al 2 O 3 and heating it with a gas plasma for re-refining to make carbon 0.01% or less and sulfur 0.005% or less. Method for refining molten Ni-based alloy.
0〜50%を含有するＦｅ−Ｎｉ系合金の溶湯を加熱手段を
有する容器へ注湯し、該容器中で真空または低酸素分圧
雰囲気で、炭素含有量が0.01%以下まで予備精錬をした
後、予備精錬時のスラグを実質的に持ち込まないで前記
容器とは別容器に移すとともに、主としてＣａＯおよび
ＣａＦ2、主としてＣａＯおよびＡl2Ｏ3、または主とし
てＣａＯ，ＣａＦ2およびＡｌ2Ｏ3からなるいずれかの
組合せの造滓剤を添加し、ガスプラズマにより加熱して
再精錬を行ない、炭素 0.01%以下、硫黄 0.005%以下に
することを特徴とするＦｅ−Ｎｉ系合金溶湯の精錬方
法。2. Pre-dissolved weight percent of at least Ni 3
A molten Fe-Ni alloy containing 0 to 50% was poured into a container having a heating means, and pre-refined to a carbon content of 0.01% or less in a vacuum or low oxygen partial pressure atmosphere in the container. After that, the slag used in the pre-smelting was transferred to a container different from the container without substantially bringing in the slag, and mainly CaO and CaF 2 , mainly CaO and Al 2 O 3 or mainly CaO, CaF 2 and Al 2 O 3 were used. A refining method for a molten Fe-Ni alloy, characterized in that the refining agent is added to any one of the following combinations and heated by gas plasma for re-refining to make carbon 0.01% or less and sulfur 0.005% or less.
するＦｅ−Ｎｉ系の合金を加熱手段を有する容器中で真
空または低酸素分圧雰囲気で、固体原料から溶解して炭
素含有量が0.01%以下まで予備精錬をした後の溶湯に、
主としてＣａＯおよびＣａＦ2、主としてＣａＯおよび
Ａl2Ｏ3、または主としてＣａＯ，ＣａＦ2およびＡｌ2
Ｏ3からなるいずれかの組合せの造滓剤を添加し、ガス
プラズマにより加熱して再精錬を行ない、炭素 0.01%以
下、硫黄 0.005%以下にすることを特徴とするＦｅ−Ｎ
ｉ系合金溶湯の精錬方法。3. A Fe-Ni-based alloy containing at least 30 to 50% by weight of Ni is melted from a solid raw material in a container having a heating means in a vacuum or low oxygen partial pressure atmosphere to obtain a carbon content. In the molten metal after preliminary refining to 0.01% or less,
Predominantly CaO and CaF 2 , predominantly CaO and Al 2 O 3 , or predominantly CaO, CaF 2 and Al 2.
Fe-N characterized by adding slag forming agent of any combination consisting of O 3 and heating by gas plasma for re-refining to make carbon 0.01% or less and sulfur 0.005% or less
Method for refining molten i-based alloy.
するＦｅ−Ｎｉ系の合金を加熱手段を有する容器中で真
空または低酸素分圧雰囲気で、固体原料から溶解して炭
素含有量が0.01%以下まで予備精錬をした後の溶湯を予
備精錬時のスラグを実質的に持ち込まないで前記容器と
は別容器に移すとともに、主としてＣａＯおよびＣａＦ
2、主としてＣａＯおよびＡl2Ｏ3、または主としてＣａ
Ｏ，ＣａＦ2およびＡｌ2Ｏ3からなるいずれかの組合せ
の造滓剤を添加し、ガスプラズマにより加熱して再精錬
を行ない、炭素 0.01%以下、硫黄 0.005%以下にするこ
とを特徴とするＦｅ−Ｎｉ系合金溶湯の精錬方法。4. A Fe-Ni alloy containing at least 30 to 50% by weight of Ni is melted from a solid raw material in a container having a heating means in a vacuum or low oxygen partial pressure atmosphere so that the carbon content is The molten metal after pre-refining to 0.01% or less is transferred to a container different from the above-mentioned container without substantially bringing in the slag used in the pre-refining, and mainly CaO and CaF
2 , predominantly CaO and Al 2 O 3 , or predominantly Ca
It is characterized by adding any combination of slag forming agents consisting of O, CaF 2 and Al 2 O 3 and heating it by gas plasma for refining to make carbon 0.01% or less and sulfur 0.005% or less. Method for refining molten Fe-Ni alloy.
する手段が酸素源または酸素源と不活性ガスの混合物を
添加または吹き込みによるものである請求項１ないし４
のいずれかに記載のＦｅ−Ｎｉ系合金溶湯の精錬方法。5. The means for adjusting the carbon content to 0.01% or less in the pre-refining is by adding or blowing an oxygen source or a mixture of an oxygen source and an inert gas.
2. A method for refining a molten Fe-Ni alloy according to any one of 1.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29251994A JP3465801B2 (en) | 1994-11-28 | 1994-11-28 | Method for refining molten Fe-Ni alloy |
| PCT/JP1994/002298 WO1996017093A1 (en) | 1994-11-25 | 1994-12-28 | Method of refining molten metal |
| DE69430541T DE69430541T2 (en) | 1994-11-25 | 1994-12-28 | METHOD FOR REFINING METAL |
| KR1019960703890A KR100227252B1 (en) | 1994-11-25 | 1994-12-28 | Method of refining molten metal |
| US08/682,597 US5851262A (en) | 1994-11-25 | 1994-12-28 | Method of refining molten metal |
| EP95904027A EP0752478B1 (en) | 1994-11-25 | 1994-12-28 | Method of refining molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29251994A JP3465801B2 (en) | 1994-11-28 | 1994-11-28 | Method for refining molten Fe-Ni alloy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08143939A true JPH08143939A (en) | 1996-06-04 |
| JP3465801B2 JP3465801B2 (en) | 2003-11-10 |
Family
ID=17782864
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29251994A Expired - Fee Related JP3465801B2 (en) | 1994-11-25 | 1994-11-28 | Method for refining molten Fe-Ni alloy |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3465801B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100921500B1 (en) * | 2007-12-28 | 2009-10-13 | 주식회사 포스코 | Method for Desulfurizing extra low carbon steel |
-
1994
- 1994-11-28 JP JP29251994A patent/JP3465801B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100921500B1 (en) * | 2007-12-28 | 2009-10-13 | 주식회사 포스코 | Method for Desulfurizing extra low carbon steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3465801B2 (en) | 2003-11-10 |
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