JPH101710A - Manufacture of chromium-aluminum-(low n)-silicon steel - Google Patents
Manufacture of chromium-aluminum-(low n)-silicon steelInfo
- Publication number
- JPH101710A JPH101710A JP17578596A JP17578596A JPH101710A JP H101710 A JPH101710 A JP H101710A JP 17578596 A JP17578596 A JP 17578596A JP 17578596 A JP17578596 A JP 17578596A JP H101710 A JPH101710 A JP H101710A
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- Prior art keywords
- molten steel
- gas
- steel
- amount
- chromium
- Prior art date
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- Treatment Of Steel In Its Molten State (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は自動車部品用材料
等としての用途を有する含Ｃｒ，Ａｌ低Ｎ,Ｓｉ鋼の製
造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a Cr-containing, Al-low N, Si steel having a use as a material for automobile parts and the like.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】含Ｃｒ
鋼の製造に際して、精錬炉内に収容した溶鋼に対してＯ
2ガスを含むガスを大気中で吹き込んで溶鋼中のＣを脱
炭し、溶鋼中のＣレベルを下げることが行われている。
この脱炭精錬はＡＯＤ法として知られている。2. Prior Art and Problems to be Solved by the Invention
During the production of steel, the molten steel contained in the smelting furnace
2. Description of the Related Art A gas containing two gases is blown in the atmosphere to decarbonize C in molten steel, thereby lowering the C level in the molten steel.
This decarburization refining is known as AOD method.
【０００３】ところでこの大気中での脱炭精錬は、溶鋼
中のＣ量が低くなってくると吹き込んだＯ2が脱炭のた
めに有効に働かず、Ｃｒを酸化してしまい脱炭効率が悪
くなる問題がある。[0003] In this decarburization refining in the atmosphere, when the C content in the molten steel becomes low, the injected O 2 does not work effectively for decarburization, oxidizes Cr and decarburization efficiency increases. There is a problem that gets worse.
【０００４】このようなことから、Ｃ量がある一定レベ
ルまで低下した時点で炉内を２０〜２００Ｔｏｒｒ程度
の減圧状態とした上、溶鋼中にＡｒガス等非酸化性ガス
を撹拌ガスとして吹き込み、溶鋼とスラグとを撹拌させ
る中で、先の大気精錬に際して酸化生成した酸化クロム
と溶鋼中のＣとを反応させて脱炭を行うとともに、酸化
クロムを一部還元する方法が本出願人によって提案され
ている。[0004] For this reason, when the amount of carbon has dropped to a certain level, the furnace is depressurized to about 20 to 200 Torr, and a non-oxidizing gas such as Ar gas is blown into the molten steel as a stirring gas. The present applicant proposes a method of causing chromium oxide generated by oxidation in the previous atmospheric refining and reacting with C in molten steel to perform decarburization while stirring molten steel and slag, and partially reducing chromium oxide. Have been.
【０００５】この方法によると、脱炭精錬を短時間で迅
速に行うことができるとともに高価なＡｒガスの使用量
を少なくでき、併せてクロムの歩留りも向上させること
ができるなどの利点が得られる。[0005] According to this method, decarburization refining can be carried out quickly in a short time, the amount of expensive Ar gas used can be reduced, and the yield of chromium can be improved. .
【０００６】ところで含Ｃｒ鋼の一種として、Ａｌを含
有し、そのＡｌ含有に基づく電気的特性に基づいて自動
車の燃料噴射装置部分に用いられる含Ｃｒ,Ａｌ鋼があ
る。このものは良好な加工性を確保する必要からＮ，Ｃ
量が低く抑えられ、またＳｉ量も低く抑えられている。
表１はその代表鋼種の化学組成を示している。As one type of Cr-containing steel, there is Cr-containing and Al-containing steel used for a fuel injection device of an automobile based on electrical characteristics based on the Al content. It is necessary to ensure good workability, so that N, C
The amount is kept low and the amount of Si is kept low.
Table 1 shows the chemical compositions of the representative steel types.
【０００７】[0007]
【表１】 [Table 1]
【０００８】この含Ｃｒ,Ａｌ低Ｎ,Ｓｉ鋼の製造方法と
して、上記大気精錬と減圧精錬とを組み合わせた製造方
法が本発明者等によって検討されている。図３及び図１
（イ）は、この含Ｃ,Ａｌ低Ｎ,Ｓｉ鋼の製造に際して上
記大気精錬と減圧精錬とを組み合わせた製造方法を適用
した場合の設備の概略構成及び各工程を表したものであ
る。As a method for producing this Cr-containing, Al-low N, Si steel, a production method combining the above-described atmospheric refining and reduced pressure refining has been studied by the present inventors. 3 and 1
(A) shows the schematic configuration of the equipment and the respective steps in the case of applying a production method combining the above-mentioned atmospheric refining and reduced pressure refining in the production of this C-containing, Al-low N, Si steel.
【０００９】先ず図３において、１００は精錬炉１０２
における炉体で、１０４は溶鋼１０６に対してガス吹込
みを行うための羽口である。１０７は炉体１００の上部
開口を閉塞する蓋で、これより排気管１０８が延び出し
ており、この排気管１０８を通じて排気を行うことによ
って精錬炉１０２内部を減圧状態とすることができる。
尚、１１０は溶鋼１０６上のスラグを表している。First, in FIG. 3, reference numeral 100 denotes a smelting furnace 102.
Reference numeral 104 denotes a tuyere for injecting gas into the molten steel 106. Reference numeral 107 denotes a lid for closing an upper opening of the furnace body 100, and an exhaust pipe 108 extends from the lid. By exhausting the gas through the exhaust pipe 108, the inside of the smelting furnace 102 can be reduced in pressure.
Reference numeral 110 denotes slag on the molten steel 106.
【００１０】この精錬設備の場合、先ず蓋１０７を除い
た状態で大気精錬を行い、しかる後蓋１０７を装着して
排気管１０８を通じて炉内部を真空吸引し、精錬炉１０
２内部を減圧状態として減圧精錬を行う。In this refining facility, air refining is first performed with the lid 107 removed, and then the lid 107 is attached and the inside of the furnace is evacuated through an exhaust pipe 108 to form a refining furnace 10.
(2) Decompression refining is performed while the inside is in a reduced pressure state.
【００１１】上記方法に従って含Ｃｒ,Ａｌ低Ｎ,Ｓｉ鋼
を製造する場合、先ず大気精錬によって、即ち溶鋼中に
Ｏ2ガスを含むガス、通常はＯ2ガスとその希釈ガスとし
てのＡｒガスとを吹き込んで溶鋼中のＣの脱炭を行う。In the production of Cr-containing, Al-low N, Si steels according to the above-mentioned method, first, a gas containing O 2 gas in molten steel, usually O 2 gas and Ar gas as a diluting gas thereof, is refined by atmospheric refining. To decarbonize C in the molten steel.
【００１２】而して溶鋼中のＣ量がある一定レベルまで
低下したところで、蓋１０７を被せて次に減圧精錬を行
う。具体的には、先ず溶鋼中に今度はＡｒガス等の非酸
化性ガスのみを撹拌ガスとして吹き込み、これにより溶
鋼とスラグとを激しく撹拌してスラグ中のメタル酸化
物、主として酸化クロムと溶鋼中のＣとを反応させて溶
鋼中のＣの脱炭を行うとともに酸化クロムを一部還元す
る。そしてＣ量が目標レベルまで低下したところで、次
に還元剤を投入して酸化クロムの還元（クロム還元）を
行い、その後流滓，出鋼する。When the amount of C in the molten steel has decreased to a certain level, the cover 107 is covered and then vacuum refining is performed. Specifically, first, only a non-oxidizing gas such as Ar gas is blown into the molten steel as a stirring gas, and thereby the molten steel and the slag are vigorously stirred, whereby the metal oxides in the slag, mainly chromium oxide and the molten steel are mixed. And decarbonize C in the molten steel and partially reduce chromium oxide. Then, when the C amount has decreased to the target level, a reducing agent is then introduced to reduce chromium oxide (chromium reduction), and thereafter, slag and tapping are performed.
【００１３】ところで、ステンレス鋼等の減圧精錬に際
しては通常クロム還元の際に還元剤としてシリコン（フ
ェロシリコン）を投入することにより行う。しかしなが
ら上記のように低Ｓｉ鋼の場合には、還元剤としてＳｉ
を投入すると鋼中のＳｉ量が増してしまうため、クロム
還元剤としてかかるＳｉを用いることができない事情が
ある。加えてこの鋼種の場合、鋼中にＡｌを含有させる
必要があることからクロム還元の際に還元剤としてＡｌ
を投入するのが好都合である。In the meantime, vacuum refining of stainless steel or the like is usually carried out by introducing silicon (ferrosilicon) as a reducing agent during chromium reduction. However, as described above, in the case of low Si steel, Si is used as a reducing agent.
When Si is added, the amount of Si in the steel increases, and there is a situation that such Si cannot be used as a chromium reducing agent. In addition, in the case of this steel type, since it is necessary to contain Al in the steel, Al is used as a reducing agent during chromium reduction.
It is convenient to input
【００１４】但しこの場合、Ａｌの添加量が問題であ
る。何故なら、Ａｌの添加量がＦｅ，Ｍｎ，Ｃｒ等のメ
タル酸化物、特に主として酸化クロムを還元するのに必
要な量よりも過剰であるとＡｌがスラグ中のＳｉＯ2を
も還元してしまってＳｉが鋼中に入り込んでしまい、結
果的に鋼中Ｓｉの含有量が増してしまい、Ｓｉ量が規格
値よりも過剰になってしまう。またＡｌの添加量によっ
ては、鋼中のＡｌ含有量そのものも規格値を超えてしま
う恐れがある。However, in this case, the amount of Al added is a problem. If the added amount of Al is more than the amount required to reduce metal oxides such as Fe, Mn, and Cr, particularly, mainly chromium oxide, Al also reduces SiO 2 in the slag. As a result, Si enters the steel, and as a result, the content of Si in the steel increases, and the amount of Si exceeds the standard value. Also, depending on the amount of Al added, the Al content itself in the steel may exceed the standard value.
【００１５】他方、逆にＡｌの添加量が不足すれば脱酸
不良（還元不足）を招き、また同時に脱Ｎ不足をも招来
する。これは、脱Ｎの難易は鋼中の酸素の量に依存する
ことによるものであり、脱酸不足により鋼中酸素が多い
と脱Ｎが良好になされなくなるからである。On the other hand, if the addition amount of Al is insufficient, insufficient deoxidization (insufficient reduction) is caused, and at the same time, insufficient N is removed. This is because the difficulty of denitrification depends on the amount of oxygen in the steel, and if there is a large amount of oxygen in the steel due to insufficient deoxidation, denitration cannot be performed well.
【００１６】これらのことから、Ａｌ添加に際してＡｌ
を過不足なく添加することが求められるが、実際にはＡ
ｌを過不足なく添加するといったことは至難であり、現
実的な方法としては採用し得ないものである。From these facts, when Al is added, Al is added.
Is required to be added without excess or deficiency.
It is extremely difficult to add l without excess or deficiency, and it cannot be adopted as a practical method.
【００１７】[0017]
【課題を解決するための手段】本願の発明はこのような
課題を解決するためになされたものである。而して本願
の発明は、含Ｃｒ,Ａｌ低Ｎ,Ｓｉ鋼の製造に際して、先
ず溶鋼中のＣを低減するための脱炭処理を行った後に、
還元剤として酸化クロムを主とするメタル酸化物の還元
に必要な理論量よりも過剰量のＡｌを投入して該酸化ク
ロムの還元を行い、しかる後該過剰量のＡｌ及び過剰量
のＡｌ投入により還元されたＳｉを溶鋼より除去するた
めのＯ2ガスの吹込みを行い、しかる後スラグを取り除
いた上で溶鋼中にＡｌを添加して、該溶鋼に必要量まで
Ａｌを含有させることを特徴とする（請求項１）。The invention of the present application has been made to solve such a problem. Thus, the invention of the present application is to carry out a decarburization treatment for reducing C in molten steel at the time of producing Cr-containing, Al low N, Si steel,
The chromium oxide is reduced by adding an excess amount of Al to the stoichiometric amount necessary for the reduction of a metal oxide mainly composed of chromium oxide as a reducing agent, and then the excess amount of Al and the excess amount of Al are added. Is performed by blowing O 2 gas to remove Si reduced by the molten steel from the molten steel, and then removing slag and then adding Al to the molten steel to allow the molten steel to contain Al to a required amount. Features (Claim 1).
【００１８】請求項２の方法は、請求項１において、前
記クロム還元の後のＯ2ガスの吹込みの際に該Ｏ2ガスを
前記過剰量のＡｌの酸化除去に必要な理論量だけ吹き込
むことを特徴とする。[0018] according to claim 2 method in claim 1, blown by the theoretical amount necessary the O 2 gas during the blow of the O 2 gas after the chromium reduced to oxidation removal of Al of the excess It is characterized by the following.
【００１９】請求項３の方法は、請求項１又は２におい
て、精錬炉内に大気圧下でＯ2ガスを含むガスの吹込み
を行って大気精錬による一次脱炭を行い、しかる後炉内
部を減圧状態とした上で非酸化性のガスを撹拌ガスとし
て吹き込むことで溶鋼とスラグとの撹拌を行いつつ酸化
クロムと溶鋼中のＣとの反応を行わせて二次脱炭を行
い、引き続いて減圧状態の下で前記クロム還元，Ｏ2ガ
ス吹込みを行うことを特徴とする。The method according to claim 3 is the method according to claim 1 or 2, wherein a gas containing O 2 gas is blown into the smelting furnace at atmospheric pressure to perform primary decarburization by atmospheric smelting, and thereafter the inside of the furnace is Is pressurized, and a non-oxidizing gas is blown as a stirring gas to cause a reaction between chromium oxide and C in the molten steel while stirring the molten steel and the slag to perform secondary decarburization. The chromium reduction and O 2 gas blowing are performed under reduced pressure.
【００２０】[0020]
【作用及び発明の効果】上記のように本発明は、脱炭処
理後のクロム還元に際して過剰量のＡｌを還元剤として
一旦投入し、しかる後Ｏ2ガス吹込みによって過剰のＡ
ｌを溶鋼中より除去するもので、本発明によれば、過剰
のＡｌの投入によりスラグ中の酸化クロムを十分に還元
することができるとともに、溶鋼中の酸素量を低減して
脱Ｎを促進することが可能となる。As described above, according to the present invention, an excess amount of Al is once introduced as a reducing agent in the reduction of chromium after the decarburization treatment, and then excess A is injected by blowing O 2 gas.
According to the present invention, chromium oxide in the slag can be sufficiently reduced by adding excessive Al, and the amount of oxygen in the molten steel is reduced to promote denitrification. It is possible to do.
【００２１】而して溶鋼中に過剰に含有されたＡｌはそ
の後のＯ2の吹込みにより除去され、その後に改めてＡ
ｌを溶鋼中に添加することで容易に溶鋼中にＡｌを必要
量まで含有させることができる。The Al excessively contained in the molten steel is removed by the subsequent injection of O 2 , and after that, A is renewed.
By adding l to molten steel, Al can be easily contained in the molten steel to a required amount.
【００２２】本発明では、クロム還元の後のＯ2ガスの
吹込みの際にＯ2ガスを過剰量のＡｌの酸化除去に必要
な理論量だけ吹き込むことができる（請求項２）。この
ようにすることによって、Ｏ2吹込みにより溶鋼中に酸
素が過剰に含有されるのを防止することができ、ひいて
はその後における溶鋼へのＡｌの添加に際して、容易に
溶鋼中に必要量でＡｌを含有させることができる。[0022] In the present invention, it can be blown in the blow of the O 2 gas after the chromium reduction of O 2 gas by the theoretical amount required for the oxidation removal of excess Al (claim 2). By doing so, it is possible to prevent oxygen from being excessively contained in the molten steel due to O 2 injection, and thus, when Al is subsequently added to the molten steel, the required amount of Al can be easily incorporated into the molten steel. Can be contained.
【００２３】本発明は、上記大気精錬と減圧精錬とを組
み合わせた製造方法に特に好適に適用することができ
る。具体的には、精錬炉内に大気圧下でＯ2ガスを含む
ガスの吹込みを行って大気精錬による一次脱炭を行い、
しかる後炉内部を減圧状態とした上で非酸化性のガスを
撹拌ガスとして吹き込むことで溶鋼中のＣの二次脱炭を
行い、続いてクロム還元，Ｏ2ガス吹込みを行った上で
最終的にＡｌ添加によりＡｌ含有量の調整を行うように
することができる（請求項３）。The present invention can be particularly suitably applied to a production method in which the above-described atmospheric refining and reduced pressure refining are combined. Specifically, primary decarburization by atmospheric refining is performed by injecting gas containing O 2 gas under atmospheric pressure into the refining furnace,
Thereafter, the inside of the furnace was depressurized, and then a non-oxidizing gas was blown as a stirring gas to perform secondary decarburization of C in the molten steel, followed by chromium reduction and O 2 gas blowing. Finally, the Al content can be adjusted by adding Al (claim 3).
【００２４】[0024]
【発明の実施の形態】図１（ロ）は本発明の好ましい実
施の形態を各工程に分けて表したものである。図１
（ロ）に示す実施の形態にあっては、先ず大気精錬によ
って脱炭を行い、鋼中のＣを所定レベルまで低下させ
る。具体的には例えば精錬炉の溶鋼中にＯ2ガスと希釈
ガス、例えばＡｒガスの吹込みを行って脱炭を行う。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1B shows a preferred embodiment of the present invention divided into respective steps. FIG.
In the embodiment shown in (b), first, decarburization is performed by atmospheric refining to reduce C in steel to a predetermined level. Specifically, for example, O 2 gas and a diluting gas, for example, Ar gas are blown into molten steel in a refining furnace to perform decarburization.
【００２５】而してＣ量が一定レベルまで低下したとこ
ろで精錬炉を減圧状態として次に減圧精錬を行う。その
減圧条件としては通常２０〜２００Ｔｏｒｒであり、最
終的に目標とするＣ量に応じてその減圧度は適宜に選択
・調整する。When the C content has dropped to a certain level, the refining furnace is set in a reduced pressure state, and then reduced pressure refining is performed. The pressure reduction condition is usually 20 to 200 Torr, and the pressure reduction degree is appropriately selected and adjusted according to the finally targeted C amount.
【００２６】この減圧精錬では、先ずＡｒガス等の非酸
化性のガスを撹拌ガスとして溶鋼中に吹き込んで溶鋼と
スラグとを撹拌しつつ、先のＯ2ガスの吹込みによって
生成した、主として酸化クロムと溶鋼中のＣとを反応さ
せて脱炭を行う。そしてＣ量が目標レベルまで低下した
ら、次に還元剤としてＡｌを投入しクロム還元を行う。
このとき、Ａｌを酸化クロムを主とするメタル酸化物の
還元に必要な理論量よりも過剰に添加する。このときＡ
ｌを過剰に添加することによって、スラグ中のＳｉＯ2
がＡｌにより還元され、Ｓｉが溶鋼中に入り込む。また
併せて過剰に添加したＡｌも溶鋼中に入り込む。In this vacuum refining, first, a non-oxidizing gas such as Ar gas is blown into the molten steel as a stirring gas to stir the molten steel and the slag, and while the molten steel and the slag are stirred, the oxidizing gas generated by the preceding injection of the O 2 gas is mainly used. Chromium reacts with C in molten steel to perform decarburization. Then, when the C amount has decreased to the target level, chromium is reduced by adding Al as a reducing agent.
At this time, Al is added in excess of a stoichiometric amount required for reduction of a metal oxide mainly composed of chromium oxide. Then A
1 in excess, the SiO 2 in the slag
Is reduced by Al, and Si enters the molten steel. In addition, excessively added Al also enters the molten steel.
【００２７】そこで次に溶鋼中へのＯ2ガスの吹込みを
行う。このとき先に添加したＡｌの過剰量分だけＯ2ガ
スの吹込みを行う。即ち、Ａｌの過剰添加に基づいて溶
鋼中に含有されたＡｌ及びＳｉＯ2の還元により溶鋼中
に入り込んだＳｉを除去するのに必要な理論量のＯ2ガ
スの吹込みを行う。Then, O 2 gas is blown into the molten steel. At this time, the O 2 gas is blown in the excess amount of Al added earlier. That is, a theoretical amount of O 2 gas necessary to remove Si that has entered into the molten steel by reduction of Al and SiO 2 contained in the molten steel based on excessive addition of Al is blown.
【００２８】しかる後最終撹拌を実施し、続いて流滓，
出鋼を行う。そして別途の取鍋において溶鋼中にＡｌ添
加を行う。このとき溶鋼中のＡｌ量が最終目標とするＡ
ｌ量となるまで添加を行う。After that, the final stirring is carried out.
Perform tapping. Then, Al is added to the molten steel in a separate ladle. At this time, the amount of Al in the molten steel is the final target A
Add until the amount is 1.
【００２９】[0029]
【実施例】次に本発明の実施例を以下に詳述する。表１
に示す化学組成の鋼種を図２に示す工程に従って製造し
た。即ち、先ず大気精錬を行って鋼中のＣの脱炭を行
い、そしてＣ量が０．０５％となったところで大気精錬
から減圧精錬に切り替えて引き続き二次脱炭精錬を行
い、引き続いてクロム還元工程を実施した。Next, embodiments of the present invention will be described in detail. Table 1
A steel grade having the chemical composition shown in FIG. 2 was produced according to the process shown in FIG. That is, first, atmospheric refining is performed to decarburize C in steel, and when the amount of C becomes 0.05%, air refining is switched from atmospheric refining to decompression refining, and secondary decarburizing refining is performed. A reduction step was performed.
【００３０】ここで二次脱炭精錬は、溶鋼へのＡｒガス
等の非酸化性の撹拌ガスを吹き込んで溶鋼とスラグとを
撹拌させる中で、スラグと溶鋼中のＣとを反応させるこ
とにより行った。尚クロム還元工程の実施は、鋼中のＣ
量が目標とする０．００３％まで低下した段階で行っ
た。Here, the secondary decarburization refining is performed by reacting the slag with C in the molten steel while stirring the molten steel with the slag by blowing a non-oxidizing stirring gas such as Ar gas into the molten steel. went. Note that the chromium reduction step is carried out based on C in steel.
The test was carried out when the amount dropped to the target of 0.003%.
【００３１】またこのクロム還元は、還元剤としてＡｌ
を投入することにより行った。その際Ａｌの添加量は酸
化クロムを主とするメタル酸化物の還元に必要な量より
も過剰量とした。このクロム還元工程の終了後におい
て、溶鋼中のＣ，Ｓｉ，Ａｌの含有量はそれぞれ図２に
示しているように０．００３％，０．０３％，０．０７
％であった。This chromium reduction is carried out by using Al as a reducing agent.
Was carried out. At that time, the amount of Al added was an excess amount than the amount required for reduction of the metal oxide mainly composed of chromium oxide. After the completion of the chromium reduction step, the contents of C, Si, and Al in the molten steel are 0.003%, 0.03%, and 0.07%, respectively, as shown in FIG.
%Met.
【００３２】ここで０．０３％のＳｉは過剰量のＡｌの
添加によりスラグのＳｉＯ2が還元されて溶鋼中に入り
込んだものである。また０．０７％のＡｌは過剰量のＡ
ｌ添加によって溶鋼中に新たに含有されたものである。Here, 0.03% of Si is obtained by reducing the SiO 2 of the slag into the molten steel by adding an excessive amount of Al. Also, 0.07% of Al is excessive A
It is newly contained in molten steel by the addition of l.
【００３３】引き続いて溶鋼中のＡｌ，Ｓｉを除去する
のに必要な理論量でＯ2ガス吹込みを行った。この結
果、溶鋼中のＳｉ，Ａｌはそれぞれ実質上０％となり、
Ｃ量は０．００３％であった。その後引き続いて撹拌を
行い、その後流滓、取鍋への出鋼を行い、そしてその取
鍋中の溶鋼に対してＡｌを改めて添加し、溶鋼中のＡｌ
の含有量を０．０７５％とした。尚、この時点で鋼中に
Ｓｉが０．０３％含有されていたが、これは取鍋から溶
鋼中に移行したものである。Subsequently, O 2 gas was blown at a stoichiometric amount necessary for removing Al and Si in the molten steel. As a result, Si and Al in the molten steel become substantially 0%, respectively.
The C amount was 0.003%. After that, stirring was continuously performed, and then the tapping and tapping to the ladle were performed, and Al was added again to the molten steel in the ladle, and the Al in the molten steel was added.
Was 0.075%. At this point, 0.03% of Si was contained in the steel, but this was transferred from the ladle to the molten steel.
【００３４】以上本発明の実施例を詳述したがこれはあ
くまで一例示であり、本発明はその主旨を逸脱しない範
囲において種々変更を加えた態様で実施可能である。Although the embodiment of the present invention has been described in detail, this is merely an example, and the present invention can be implemented in variously modified forms without departing from the gist thereof.
【図１】本発明の製造方法の望ましい実施の形態の各工
程を比較例とともに示す図である。FIG. 1 is a diagram showing each step of a preferred embodiment of a manufacturing method of the present invention together with a comparative example.
【図２】本発明の一実施例方法の各工程と溶鋼中の所定
成分の変化の状況を示す図である。FIG. 2 is a diagram showing each step of a method of an embodiment of the present invention and a state of a change of a predetermined component in molten steel.
【図３】本発明の実施例において用いた精錬炉の図であ
る。FIG. 3 is a view of a smelting furnace used in an embodiment of the present invention.
１００ 炉体 １０２ 精錬炉 １０４ 羽口 １０６ 溶鋼 １０７ 蓋 １１０ スラグ DESCRIPTION OF SYMBOLS 100 Furnace body 102 Refining furnace 104 Tuyere 106 Molten steel 107 Lid 110 Slag
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ２１Ｃ 7/10 Ｃ２１Ｃ 7/10 Ｊ ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code Agency reference number FI Technical indication location C21C 7/10 C21C 7/10 J
Claims (3)
て、先ず溶鋼中のＣを低減するための脱炭処理を行った
後に、還元剤として酸化クロムを主とするメタル酸化物
の還元に必要な理論量よりも過剰量のＡｌを投入して該
酸化クロムの還元を行い、しかる後該過剰量のＡｌ及び
過剰量のＡｌ投入により還元されたＳｉを溶鋼より除去
するためのＯ2ガスの吹込みを行い、しかる後スラグを
取り除いた上で溶鋼中にＡｌを添加して、該溶鋼に必要
量までＡｌを含有させることを特徴とする含Ｃｒ,Ａｌ
低Ｎ,Ｓｉ鋼の製造方法。1. In the production of Cr-containing, Al-low N, Si steels, a decarburization treatment for reducing C in molten steel is first performed, and then a metal oxide mainly composed of chromium oxide is reduced as a reducing agent. To reduce the chromium oxide by adding an excess amount of Al to the stoichiometric amount necessary for the removal of the chromium oxide, followed by O 2 for removing the excess Al and the Si reduced by the excess amount of Al from the molten steel. Injecting gas and then removing slag and then adding Al to the molten steel to allow the molten steel to contain Al up to a required amount.
Method for producing low N, Si steel.
のＯ2ガスの吹込みの際に該Ｏ2ガスを前記過剰量のＡｌ
の酸化除去に必要な理論量だけ吹き込むことを特徴とす
る含Ｃｒ,Ａｌ低Ｎ,Ｓｉ鋼の製造方法。2. The method of claim 1, of the excess of the O 2 gas during the blow of the O 2 gas after the chromium reducing Al
A method for producing Cr-containing, Al-low N, Si steels, characterized in that a stoichiometric amount necessary for the oxidative removal of steel is blown.
気圧下でＯ2ガスを含むガスの吹込みを行って大気精錬
による一次脱炭を行い、しかる後炉内部を減圧状態とし
た上で非酸化性のガスを撹拌ガスとして吹き込むことで
溶鋼とスラグとの撹拌を行いつつ酸化クロムと溶鋼中の
Ｃとの反応を行わせて二次脱炭を行い、引き続いて減圧
状態の下で前記クロム還元，Ｏ2ガス吹込みを行うこと
を特徴とする含Ｃｒ,Ａｌ低Ｎ,Ｓｉ鋼の製造方法。3. The method according to claim 1, wherein a gas containing O 2 gas is blown into the smelting furnace under atmospheric pressure to perform primary decarburization by atmospheric smelting, and then the inside of the furnace is reduced in pressure. By blowing a non-oxidizing gas as a stirring gas above, the reaction between chromium oxide and C in the molten steel is performed while stirring the molten steel and the slag, and secondary decarburization is performed. Wherein the chromium reduction and the O 2 gas injection are carried out.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17578596A JPH101710A (en) | 1996-06-13 | 1996-06-13 | Manufacture of chromium-aluminum-(low n)-silicon steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17578596A JPH101710A (en) | 1996-06-13 | 1996-06-13 | Manufacture of chromium-aluminum-(low n)-silicon steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH101710A true JPH101710A (en) | 1998-01-06 |
Family
ID=16002215
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17578596A Pending JPH101710A (en) | 1996-06-13 | 1996-06-13 | Manufacture of chromium-aluminum-(low n)-silicon steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH101710A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015501382A (en) * | 2011-10-25 | 2015-01-15 | 宝山鋼鉄股▲分▼有限公司 | Smelting method of high aluminum low silicon ultra pure ferritic stainless steel |
-
1996
- 1996-06-13 JP JP17578596A patent/JPH101710A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015501382A (en) * | 2011-10-25 | 2015-01-15 | 宝山鋼鉄股▲分▼有限公司 | Smelting method of high aluminum low silicon ultra pure ferritic stainless steel |
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