JP2000104112A - Method for refining high aluminum-containing stainless steel - Google Patents
Method for refining high aluminum-containing stainless steelInfo
- Publication number
- JP2000104112A JP2000104112A JP10278106A JP27810698A JP2000104112A JP 2000104112 A JP2000104112 A JP 2000104112A JP 10278106 A JP10278106 A JP 10278106A JP 27810698 A JP27810698 A JP 27810698A JP 2000104112 A JP2000104112 A JP 2000104112A
- Authority
- JP
- Japan
- Prior art keywords
- mgo
- refining
- stainless steel
- slag
- cao
- 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.)
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Classifications
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- 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]
【発明の属する技術分野】本発明はステンレス鋼の精錬
方法に係り、とくにAlを１〜10wt％含有する高Al含有ス
テンレス鋼の２次精錬方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for refining stainless steel, and more particularly to a method for secondary refining of a high Al content stainless steel containing 1 to 10% by weight of Al.
【０００２】[0002]
【従来の技術】ステンレス鋼は、従来から、転炉、電気
炉で１次精錬されたのち、AOD 、VOD等の２次精錬設備
で、脱炭処理、脱酸・還元処理からなる２次精錬を施さ
れて溶製されている。従来、Alを１〜10wt％含有する高
Al含有ステンレス鋼の２次精錬は、Al2O3 耐火物を用い
た取鍋（精錬容器）で行われてきた。例えば、特開平3-
158410号公報には、3.0 重量％以上を含有する高Al含有
ステンレス鋼の精錬において、鋼中のMg濃度を低下する
ために、鋼中Alを調整する際にスラグのCaO/Al2O 3 を0.
8 〜1.2 に調整し、かつスラグ中のSiO2＋MgO ＋MnO を
５重量％以下に調整するフェライト系ステンレス鋼の製
造方法が提案され、スラグ中のSiO2＋MgO＋MnO を５重
量％以下とする方法として、精錬容器内張りレンガ材質
をAl2O3 を95重量％以上とすることが開示されている。2. Description of the Related Art Conventionally, stainless steel has been
After the primary refining in the furnace, secondary refining equipment such as AOD and VOD
In the secondary refining consisting of decarburization treatment, deoxidation and reduction treatment
It is made by melting. Conventionally, high content containing 1 to 10 wt% Al
Secondary refining of Al-containing stainless steelTwoOThreeUsing refractories
It has been done in a ladle (refining vessel). For example, JP-A-3-
No. 158410 discloses a high Al content containing more than 3.0% by weight.
Reduces Mg concentration in steel during refining of stainless steel
Therefore, when adjusting Al in steel, CaO / AlTwoO ThreeTo 0.
Adjusted to 8 ~ 1.2 and SiO in slagTwo+ MgO + MnO
Made of ferritic stainless steel adjusted to 5% by weight or less
Fabrication method was proposed, and SiO in slag wasTwo+ MgO + MnO 5 times
As a method to reduce the amount to less than%,
AlTwoOThreeTo 95% by weight or more.
【０００３】しかし、Al2O3 耐火物を用いた取鍋（精錬
容器）は、特殊鍋であるためチャンスフリーで溶製する
ことができないうえ、高価であるため、コストアップの
原因となっていた。However, a ladle (refining vessel) using Al 2 O 3 refractory is a special pan and cannot be melted in a chance-free manner, and is expensive, leading to an increase in cost. Was.
【０００４】[0004]
【発明が解決しようとする課題】一方、Al2O3 耐火物を
用いた取鍋（精錬容器）に代えて、安価なMgO 含有耐火
物を用いた取鍋（精錬容器）を用いて精錬した場合に
は、取鍋（精錬容器）の耐火物からMgO が溶出し、スラ
グ中のMgO 濃度が高くなる。MgO 濃度の高いスラグの存
在下で、多量のAl（例えば、10〜120kg/t-steel ）を一
括して投入すると、添加直後、スラグ近傍の高濃度Al領
域において、スラグ中のMgO とAlが反応し、Mg蒸気を発
生させるため、そのMg蒸気が大気中で酸化されることに
より発火するという問題があった。そのために、MgO 含
有耐火物を用いた取鍋（精錬容器）で高Al含有ステンレ
ス鋼を溶製する場合には、Alは少量ずつ分割して添加す
ることが要請され、そのため処理時間が大幅に延長し、
コッストアップの一つの要因となっていた。On the other hand, smelting was performed using a ladle (refining vessel) using an inexpensive refractory containing MgO instead of a ladle (refining vessel) using Al 2 O 3 refractory. In this case, MgO elutes from the refractory of the ladle (refining vessel), and the MgO concentration in the slag increases. When a large amount of Al (for example, 10 to 120 kg / t-steel) is added at once in the presence of slag with a high MgO concentration, immediately after the addition, MgO and Al in the slag in the high concentration Al region near the slag are added. There is a problem that the Mg vapor is oxidized in the atmosphere and fires because it reacts to generate Mg vapor. Therefore, when smelting high-Al-containing stainless steel using a ladle (refining vessel) using a refractory containing MgO, it is required that Al be added in small portions and the processing time is greatly reduced. Extend,
It was one of the factors of cost up.
【０００５】本発明は、上記した従来技術の問題に鑑
み、安価なMgO 含有耐火物を用いた精錬容器を用いて安
全でかつ短時間に、Alが１〜10wt％含有する高Al含有ス
テンレス鋼を２次精錬できる高Al含有ステンレス鋼の精
錬方法を提案することを目的とする。In view of the above-mentioned problems of the prior art, the present invention provides a high-Al content stainless steel containing 1 to 10% by weight of Al safely and quickly using a refining vessel using an inexpensive MgO-containing refractory. It is an object of the present invention to propose a method for refining a high Al-containing stainless steel capable of secondary refining.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、上記課題
を達成するため、鋭意研究した結果、Mg蒸気の発生を抑
制するには、スラグ中MgO 濃度の最も低い時期にAlを添
加することが重要であることに思い至った。従来の高Al
含有ステンレス鋼のVOD 処理では、図３に示すように、
まず酸素ガスを上吹きし溶鋼を脱炭する脱炭処理期と、
その後、酸素吹精を止め、高真空下で還元剤（Fe-Si ）
を添加しArガスを底吹きし溶鋼とスラグを攪拌しなが
ら、溶湯の脱酸、スラグ中Crの還元等を行う脱酸・還元
処理期からなる。Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, to suppress the generation of Mg vapor, Al is added at the time when the MgO concentration in the slag is the lowest. I realized that it was important. Conventional high Al
In the VOD treatment of the contained stainless steel, as shown in FIG.
First, a decarburization period in which oxygen gas is blown upward to decarbonize the molten steel,
After that, stop oxygen blowing and use a reducing agent (Fe-Si) under high vacuum.
Is added, and the Ar gas is blown to the bottom to agitate the molten steel and the slag while deoxidizing the molten metal and reducing Cr in the slag.
【０００７】そこで、まず、含MgO 耐火物を用いた取鍋
でAlキルドステンレス鋼をVOD 処理した際の、スラグ中
MgO 濃度の変化を調査した。その結果を図１に示す。図
１から、脱炭処理期には、スラグ中MgO 濃度は低位に推
移し、耐火物からのMgO の溶出は全く無いことがわか
る。その後、還元剤を添加してスラグおよび溶湯を底吹
きガスにより撹拌する脱酸・還元処理期には、スラグ中
MgO 濃度が急激に増加しており、この時期に耐火物から
のMgO の溶出が発生していることがわかる。このことか
ら、MgO とAlの反応を少なくするため、Alの多量添加
は、脱炭処理後で脱酸・還元処理前に行うのがよいとい
う知見を得た。Therefore, first, when Al-killed stainless steel was subjected to VOD treatment with a ladle using MgO-containing refractory, the slag in the slag was removed.
The change in MgO concentration was investigated. The result is shown in FIG. From FIG. 1, it can be seen that during the decarburization period, the MgO concentration in the slag was low, and there was no MgO elution from the refractory. Thereafter, during the deoxidation / reduction treatment period in which the reducing agent is added and the slag and the molten metal are stirred by the bottom blowing gas,
The MgO concentration increased sharply, indicating that MgO was eluted from the refractory at this time. From this, it has been found that in order to reduce the reaction between MgO and Al, a large amount of Al should be added after the decarburizing treatment and before the deoxidizing / reducing treatment.
【０００８】従来、MgO を含む耐火物を用いた取鍋で高
Al含有ステンレス鋼のVOD 処理を行った場合には、脱酸
・還元処理後のスラグ中MgO 濃度の高い時期に大量（10
〜120kg/t ）のAlを添加していたために、Alとスラグ中
MgO が反応したものと考えられる。また、本発明者ら
は、さらにスラグ組成を変化し、スラグ中MgO とAlの反
応について調査した。Mg蒸気発生量とスラグ組成の関係
を図２に示す。Conventionally, a ladle using a refractory containing MgO has been
When VOD treatment was performed on Al-containing stainless steel, large amounts (1010) were obtained when the MgO concentration in the slag after deoxidation / reduction treatment was high.
~ 120kg / t) Al and slag
It is considered that MgO reacted. The present inventors further changed the slag composition and investigated the reaction between MgO and Al in the slag. FIG. 2 shows the relationship between the amount of Mg vapor generated and the slag composition.
【０００９】図２から、スラグ中MgO 濃度およびCaO/Al
2O3 が高くなるにしたがって、Mg蒸気の発生が多くなる
ことがわかる。また、スラグCaO/Al2O3 が低くなるほど
Mg蒸気の発生量は少なくなるが、CaO/Al2O3 が0.5 未満
では、スラグはAl2O3 が飽和し、完全に固化してしまう
ために、実際の処理には適さない。このようなことか
ら、Mg蒸気の発生を抑制し、Alを一括して多量に添加で
き、処理時間を短縮するためには、Alの多量添加時のス
ラグ組成を、CaO/Al2O3 が0.5 〜0.7 の範囲で、かつMg
O 濃度が０〜５wt％の範囲とすることが好適であるとい
う知見を得た。FIG. 2 shows that the MgO concentration in the slag and the CaO / Al
It can be seen that the generation of Mg vapor increases as the 2 O 3 increases. Also, as the slag CaO / Al 2 O 3 becomes lower,
Although the amount of Mg vapor generated is reduced, if CaO / Al 2 O 3 is less than 0.5, the slag is not suitable for actual treatment because Al 2 O 3 is saturated and completely solidified. Therefore, in order to suppress the generation of Mg vapor and to add a large amount of Al in a lump, and to shorten the processing time, the slag composition when a large amount of Al is added, CaO / Al 2 O 3 0.5 to 0.7 and Mg
It has been found that the O concentration is preferably in the range of 0 to 5 wt%.
【００１０】本発明は、上記した知見に基づいて構成さ
れたものである。すなわち、本発明は、MgO 含有耐火物
を用いた精錬容器を使用する２次精錬設備で、Alを１〜
10wt％含有する高Al含有ステンレス鋼を精錬するに際
し、脱炭処理後であって脱酸・還元処理前に所定量のAl
を添加することを特徴とする高Al含有ステンレス鋼の精
錬方法であり、また、本発明では、前記所定量のAlを添
加する際のスラグ組成を、CaO 濃度とAl2O3 濃度の比、
CaO/Al2O3 が0.5 〜0.7 で、かつMgO 濃度が０または５
wt％以下とするのが好ましい。The present invention has been made based on the above findings. That is, the present invention relates to a secondary refining facility using a refining vessel using a refractory containing MgO,
When refining stainless steel containing high Al containing 10 wt%, a specified amount of Al
A refining method for a high Al-containing stainless steel, characterized by adding a slag composition at the time of adding the predetermined amount of Al, a ratio of CaO concentration to Al 2 O 3 concentration,
CaO / Al 2 O 3 is 0.5 to 0.7 and MgO concentration is 0 or 5
It is preferred to be not more than wt%.
【００１１】[0011]
【発明の実施の形態】本発明では、転炉あるいは電気炉
で１次精錬を行ったステンレス鋼溶湯を、MgO 含有耐火
物を用いた精錬容器を使用する２次精錬設備で精錬し、
高Al含有のステンレス鋼を溶製する。２次精錬設備は、
ＶＯＤ設備、あるいはＡＯＤ設備がいずれも好適に使用
でき、また２次精錬設備で用いる精錬容器は、MgO 含有
耐火物、を内張りした取鍋等の容器を使用する。具体的
にはMgO 含有耐火物は、マグネシア−カーボン系耐火物
が好ましい。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a stainless steel melt that has been subjected to primary refining in a converter or an electric furnace is refined in a secondary refining facility using a refining vessel using a refractory containing MgO.
Melting stainless steel with high Al content. The secondary refining equipment
Either a VOD facility or an AOD facility can be suitably used, and a refining vessel used in the secondary refining facility is a ladle or the like lined with a refractory containing MgO. Specifically, the MgO-containing refractory is preferably a magnesia-carbon refractory.
【００１２】１次精錬されたステンレス鋼溶湯は、精錬
容器に移され、２次精錬設備で２次精錬される。２次精
錬について、ＶＯＤ処理を例に説明する。なお、本発明
における２次精錬はＶＯＤ処理に限定されるものではな
いことは言うまでもない。取鍋（精錬容器）に移された
ステンレス鋼溶湯は、上吹きランスから酸素ガスを上吹
きする脱炭処理を施されて、脱炭される。その後、還元
剤を添加して、高真空下でArガスを底吹きし溶湯とスラ
グを攪拌し溶湯の脱酸とスラグの還元を行う脱酸・還元
処理を施される。還元剤としては、Fe-Si 、あるいはAl
が好ましい。The primary refined stainless steel melt is transferred to a refining vessel and secondary refined in a secondary refining facility. The secondary refining will be described using a VOD process as an example. It goes without saying that the secondary refining in the present invention is not limited to the VOD process. The stainless steel melt transferred to the ladle (refining vessel) is subjected to a decarburization treatment in which oxygen gas is blown upward from an upper blowing lance, and is decarbonized. Thereafter, a reducing agent is added, Ar gas is blown down under high vacuum, and the molten metal and the slag are agitated to perform a deoxidizing / reducing treatment for deoxidizing the molten metal and reducing the slag. Fe-Si or Al as a reducing agent
Is preferred.
【００１３】本発明で対象とする高Al含有ステンレス鋼
は、Alを１〜10wt％含有するステンレス鋼である。本発
明では、Alの添加は、脱炭処理終了後で脱酸・還元処理
前に行う。脱酸・還元処理後では、スラグ中のMgO 濃度
が高く、Alの大量添加を行うとMg蒸気の発生が著しくな
り、２次精錬作業が危険となる。ここで、Alの大量添加
とは、Alを、10〜120kg/t-steel 一括して添加すること
をいう。The high Al-containing stainless steel to be used in the present invention is a stainless steel containing 1 to 10 wt% of Al. In the present invention, Al is added after the decarburization treatment and before the deoxidation / reduction treatment. After the deoxidizing / reducing treatment, the MgO concentration in the slag is high, and when a large amount of Al is added, the generation of Mg vapor becomes remarkable, and the secondary refining operation becomes dangerous. Here, adding a large amount of Al means adding Al at a time of 10 to 120 kg / t-steel.
【００１４】また、本発明では、Al添加時のスラグ組成
を、CaO 濃度とAl2O3 濃度の比、CaO/Al2O3 が0.5 〜0.
7 で、かつMgO 濃度が０〜５wt％とするのが好ましい。
CaO/Al2O3 が0.5 未満では、スラグ中のAl2O3 が飽和
し、スラグが完全に固化するため２次精錬が困難とな
る。また、CaO/Al2O3 が0.7 を超えると、Al添加時にMg
蒸気の発生が顕著となる。スラグ組成の調整は、スラグ
成分となるCaO 、Al2O3 を必要量添加し、あるいはさら
にスラグ組成の分析を適宜行いその結果に基づいて、所
定の範囲となるように添加物を装入することにより行う
のが好ましい。[0014] In the present invention, a slag composition during Al addition, CaO concentration and the concentration of Al 2 O 3 ratio, CaO / Al 2 O 3 is from 0.5 to 0.
7 and a MgO concentration of 0 to 5 wt%.
When CaO / Al 2 O 3 is less than 0.5, Al 2 O 3 in the slag is saturated and the slag is completely solidified, so that secondary refining becomes difficult. Also, when CaO / Al 2 O 3 exceeds 0.7, Mg
The generation of steam becomes remarkable. Adjusting slag composition, CaO serving as slag component, Al was added required amount 2 O 3, or even on the basis of appropriately perform the results analysis of slag composition is charged with additive to a predetermined range It is preferable to carry out this.
【００１５】また、スラグ中のMgO 濃度が５wt％を超え
ると、Al添加時にMg蒸気の発生が顕著となる。このよう
なことから、Al添加時のスラグ組成は、CaO 濃度とAl2O
3 濃度の比、CaO/Al2O3 を0.5 〜0.7 、かつMgO 濃度を
０、または５wt％以下とするのが好ましい。当然なが
ら、Al添加時にMg蒸気の発生を防止するには、スラグ中
MgO 濃度を０、すなわちスラグ中にMgO を含まないほう
が好都合である。なお、精錬容器の溶損を防止する意味
から、ドロマイト、れんが屑等を添加して少量のMgO を
スラグ中に含有させることもある。If the MgO concentration in the slag exceeds 5% by weight, the generation of Mg vapor becomes remarkable when Al is added. Therefore, the slag composition when Al is added depends on the CaO concentration and Al 2 O
3 concentration ratio, CaO / Al 2 O 3 of 0.5 to 0.7, and preferably in the a MgO concentration 0 or less 5 wt%,. Of course, to prevent the generation of Mg vapor when adding Al,
It is advantageous that the MgO concentration is 0, that is, the slag contains no MgO. In order to prevent smelting of the smelting vessel, a small amount of MgO may be contained in the slag by adding dolomite, brick waste and the like.
【００１６】[0016]
【実施例】（比較例１）転炉で１次精錬したステンレス
鋼溶湯を、含MgO 耐火物を用いた取鍋に移し、160Ton V
OD設備で２次精錬し、Alを５wt％含有する高Al含有ステ
ンレス鋼とした。２次精錬は、酸素ガス吹精による脱炭
処理後、真空中でFe-Si を7kg/t 添加し底吹きガスでの
強撹拌による脱酸・還元処理を実施し、その後、大気圧
下で38kg/tのAlを一括添加した。Al添加時のスラグ組成
は、CaO/Al2O3 ＝1.1 、MgO ＝7.3 ％であった。その結
果、Al添加後、スラグ中MgO とAlとの反応が生じ、Mg蒸
気が発生し、それが酸化し大量のMgO の白煙が取鍋より
舞い上がった。発火の危険を回避するため、そのまま処
理を中止し、溶湯を廃塊とした。なお、スラグ中のMgO
濃度は、脱炭処理期で０〜３wt％、脱酸・還元処理期で
5 〜10wt％であった。[Example] (Comparative Example 1) A molten stainless steel which was primarily refined in a converter was transferred to a ladle using MgO-containing refractory, and 160Ton V
Secondary refining was performed using an OD facility to obtain a high Al-containing stainless steel containing 5 wt% of Al. In the secondary refining, after decarburization by oxygen gas blowing, 7 kg / t of Fe-Si is added in vacuum and deoxidation and reduction by vigorous stirring with bottom blowing gas is performed. 38 kg / t of Al was added all at once. The slag composition when Al was added was CaO / Al 2 O 3 = 1.1 and MgO = 7.3%. As a result, after the addition of Al, the reaction between MgO and Al in the slag occurred, and Mg vapor was generated, which was oxidized and a large amount of MgO 4 white smoke rose from the ladle. In order to avoid the danger of ignition, the treatment was stopped and the molten metal was discarded. In addition, MgO in slag
The concentration is 0 to 3 wt% during the decarburization period and during the deoxidation / reduction period.
It was 5 to 10% by weight.
【００１７】（比較例２）転炉で１次精錬したステンレ
ス鋼溶湯を、含MgO 耐火物を用いた取鍋に移し、160Ton
VOD設備で２次精錬し、Alを５wt％含有する高Al含有ス
テンレス鋼とした。２次精錬は、酸素ガス吹精による脱
炭処理後、真空中でFe-Si を7kg/t 添加し底吹きガスで
の強撹拌による脱酸・還元処理を実施し、その後、大気
圧下で合計42kg/tのAlを、１回当たり6kg/t として７回
に分割して添加した。Al添加時のスラグ組成はCaO/Al2O
3 ＝1.2 、MgO ＝ 8.5wt％であった。その結果、比較例
１のようなMg蒸気の発生はなく、安全に精錬することが
できた。しかし、７回に分割してAlを添加したために、
Alを一括添加した場合に比べ処理時間が30min 程度長く
なった。(Comparative Example 2) A stainless steel melt primarily refined in a converter was transferred to a ladle using a refractory containing MgO, and the material was heated to 160 Ton.
Secondary refining was performed using a VOD facility to obtain a high Al-containing stainless steel containing 5 wt% of Al. In the secondary refining, after decarburization by oxygen gas blowing, 7 kg / t of Fe-Si is added in vacuum and deoxidation and reduction by vigorous stirring with bottom blowing gas is performed. A total of 42 kg / t of Al was added in 7 batches at a rate of 6 kg / t each time. The slag composition when Al is added is CaO / Al 2 O
3 = 1.2, MgO = 8.5 wt%. As a result, there was no generation of Mg vapor as in Comparative Example 1, and safe refining was possible. However, since Al was added in seven times,
The processing time was about 30 min longer than when Al was added all at once.
【００１８】（実施例１）転炉で１次精錬したステンレ
ス鋼溶湯を、含MgO 耐火物を用いた取鍋に移し、160Ton
VOD設備で２次精錬し、Alを５wt％含有する高Al含有ス
テンレス鋼とした。２次精錬は、酸素ガス吹精による脱
炭処理後、スラグ組成が、CaO/Al2O3 ＝0.65、MgO ＝
2.3wt％の時、大気圧下で40kg/tのAlを一括添加し、脱
酸・還元処理とAl量の調整を行った。その結果、Al添加
後、比較例１のようなMg蒸気の発生はなく、安全にかつ
迅速に精錬することができた。(Example 1) A stainless steel melt primarily refined in a converter was transferred to a ladle using a refractory containing MgO, and was subjected to 160 Ton.
Secondary refining was performed using a VOD facility to obtain a high Al-containing stainless steel containing 5 wt% of Al. In the secondary refining, after decarburization by oxygen gas blowing, the slag composition is CaO / Al 2 O 3 = 0.65, MgO =
At 2.3 wt%, 40 kg / t of Al was added all at once under atmospheric pressure, and deoxidation / reduction treatment and adjustment of the amount of Al were performed. As a result, after Al addition, there was no generation of Mg vapor as in Comparative Example 1, and refining could be performed safely and quickly.
【００１９】（実施例２）実施例１と同様に、160Ton V
OD設備で２次精錬し、Alを５wt％含有する高Al含有ステ
ンレス鋼とした。２次精錬は、酸素ガス吹精による脱炭
処理後、スラグ組成が、CaO/Al2O3 ＝0.85、MgO ＝ 2.0
wt％の時に、大気圧下で41kg/tのAlを一括添加し、脱酸
・還元処理とAl量の調整を行った。その結果、Al添加
後、比較例１のようなMg蒸気の多量発生はなく、安全に
かつ迅速に精錬することができた。(Embodiment 2) As in Embodiment 1, 160 Ton V
Secondary refining was performed using an OD facility to obtain a high Al-containing stainless steel containing 5 wt% of Al. In the secondary refining, after decarburization by oxygen gas blowing, the slag composition was CaO / Al 2 O 3 = 0.85, MgO = 2.0
At wt%, 41 kg / t of Al was added all at once under atmospheric pressure, and deoxidation / reduction treatment and adjustment of the amount of Al were performed. As a result, after Al addition, there was no generation of a large amount of Mg vapor as in Comparative Example 1, and refining could be performed safely and quickly.
【００２０】[0020]
【発明の効果】以上のように、本発明によれば、安価な
含MgO 耐火物を用いた取鍋（精錬容器）を使用するVOD
等の２次精錬設備において、Alを１〜10wt％含有する高
Al含有ステンレス鋼を安全でかつ迅速に精錬することが
でき、製造コストを低減することが可能となり、産業上
格段の効果を奏する。As described above, according to the present invention, a VOD using a ladle (refining vessel) using inexpensive MgO-containing refractories is used.
And other secondary refining equipment, containing 1 to 10 wt% of Al
Al-containing stainless steel can be smelted safely and quickly, and the production cost can be reduced, which has a remarkable industrial effect.
【図１】VOD 処理におけるスラグ中MgO 濃度の変化を示
すグラフである。FIG. 1 is a graph showing a change in MgO concentration in slag in VOD treatment.
【図２】Mg蒸気発生におよぼすスラグ中MgO 濃度とCaO/
Al2O3 の関係を示す説明図である。Fig. 2 MgO concentration in slag and CaO /
FIG. 3 is an explanatory diagram showing the relationship of Al 2 O 3 .
【図３】VOD 処理を模式的に示す説明図である。FIG. 3 is an explanatory diagram schematically showing a VOD process.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 廣田 哲仁 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 Ｆターム(参考） 4K013 AA01 AA02 BA02 CB09 EA19 FA05 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuhito Hirota 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba F-term inside the Chiba Works of Kawasaki Steel Co., Ltd. 4K013 AA01 AA02 BA02 CB09 EA19 FA05
Claims (2)
する２次精錬設備で、Alを１〜10wt％含有する高Al含有
ステンレス鋼を精錬するに際し、脱炭処理後であって脱
酸・還元処理前に所定量のAlを添加することを特徴とす
る高Al含有ステンレス鋼の精錬方法。In a secondary refining facility using a refining vessel using a refractory containing MgO, when refining a high Al-containing stainless steel containing 1 to 10 wt% of Al, after decarburizing treatment, deoxidizing is performed. A method for refining stainless steel containing high Al content, wherein a predetermined amount of Al is added before the reduction treatment.
成を、CaO 濃度とAl 2O3 濃度の比、CaO/Al2O3 が0.5 〜
0.7 で、かつMgO 濃度が０〜５wt％とすることを特徴と
する請求項１に記載の高Al含有ステンレス鋼の精錬方
法。2. A slag set when adding the predetermined amount of Al.
Of CaO concentration and Al TwoOThreeConcentration ratio, CaO / AlTwoOThree Is 0.5 to
0.7 and MgO concentration of 0-5 wt%
The method for refining a high Al content stainless steel according to claim 1.
Law.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27810698A JP3893769B2 (en) | 1998-09-30 | 1998-09-30 | Method for refining high Al content stainless steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27810698A JP3893769B2 (en) | 1998-09-30 | 1998-09-30 | Method for refining high Al content stainless steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000104112A true JP2000104112A (en) | 2000-04-11 |
| JP3893769B2 JP3893769B2 (en) | 2007-03-14 |
Family
ID=17592722
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27810698A Expired - Fee Related JP3893769B2 (en) | 1998-09-30 | 1998-09-30 | Method for refining high Al content stainless steel |
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| Country | Link |
|---|---|
| JP (1) | JP3893769B2 (en) |
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1998
- 1998-09-30 JP JP27810698A patent/JP3893769B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| JP3893769B2 (en) | 2007-03-14 |
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