JPH10219337A - Method for smelting high clean steel - Google Patents
Method for smelting high clean steelInfo
- Publication number
- JPH10219337A JPH10219337A JP3144597A JP3144597A JPH10219337A JP H10219337 A JPH10219337 A JP H10219337A JP 3144597 A JP3144597 A JP 3144597A JP 3144597 A JP3144597 A JP 3144597A JP H10219337 A JPH10219337 A JP H10219337A
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- Prior art keywords
- steel
- molten steel
- less
- ppm
- deoxidation
- 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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- 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ＲＨ脱ガス装置を使
用した高清浄鋼の溶製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 melting high-purity steel using an RH degassing apparatus.
【０００２】[0002]
【従来の技術】製鋼工程で鋼中に発生するアルミナ（Ａ
ｌ2 Ｏ3 ）が溶鋼から除去されずに介在物として鋼中に
残ると、一般に製品欠陥の原因となる。アルミナは、 ２Ａｌ +３Ｏ＝Ａｌ2 Ｏ3 の反応により生成したものであり、Ａｌによる鋼の脱酸
およびその後の再酸化により発生する。2. Description of the Related Art Alumina (A) generated in steel in a steel making process
If l 2 O 3 ) remains in the steel as inclusions without being removed from the molten steel, it generally causes product defects. Alumina, 2Al + 3O = are those produced by the reaction of Al 2 O 3, produced by the re-oxidation deoxidation and subsequent steel by Al.
【０００３】従来脱酸生成物を除去するためには、ＲＨ
脱ガス装置で酸化物を凝集させ、浮上分離を促進するた
めに、脱酸後の脱ガス時間を長くし、あるいは特開平７
−３００６１０号公報に開示されているように、Ｃａ
Ｏ，Ａｌ2 Ｏ3 等のスラグ改質剤を溶鋼に吹き付けて介
在物の合体浮上を促進する等の方法がとられている。ま
た溶鋼の再酸化を防止するために、例えば特開平４−７
２００９号公報に開示されているようにスラグ改質を行
い、スラグ中のＦｅＯを低減する等の方法がある。[0003] Conventionally, to remove deoxidation products, RH
In order to coagulate oxides in a degassing device and promote flotation, the degassing time after deoxidation is lengthened.
As disclosed in Japanese Unexamined Patent Publication No.
A method has been adopted in which a slag modifier such as O, Al 2 O 3 or the like is sprayed on molten steel to promote the combined floating of inclusions. Further, in order to prevent reoxidation of molten steel, for example, Japanese Patent Application Laid-Open No.
As disclosed in JP-A-2009-2009, there is a method of performing slag reforming to reduce FeO in the slag.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、これら
の方法は、溶鋼中に発生した介在物の除去あるいは再酸
化の防止には有効であるが、例えばＣ量０．１０ｗｔ％
以下の低炭素鋼である食缶等の極度に清浄性の要求され
るような鋼を製造するためには、発生する介在物の総量
を規定しないと、不十分であることを発明者らは見出し
た。そこで、本発明は鋼中のアルミナ系介在物の全発生
量を低減し、かつ浮上分離を促進し、再酸化を防止する
ことにより安定的に高清浄鋼を溶製する方法を提供する
ことを目的とするものである。However, these methods are effective for removing inclusions generated in the molten steel or preventing reoxidation. For example, the C content is 0.10 wt%.
The present inventors have found that in order to manufacture steel such as the following low-carbon steel, such as a food can, in which extremely cleanliness is required, it is insufficient unless the total amount of inclusions to be generated is specified. I found it. Therefore, the present invention provides a method for stably producing a high-purity steel by reducing the total amount of alumina-based inclusions in steel, promoting flotation separation, and preventing reoxidation. It is the purpose.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するた
め、種々研究した結果、下記の発明をするに至った。第
１の発明は、下記の工程を備えたことを特徴とする高清
浄鋼の溶製方法である。 （ａ）転炉で鋼を溶製し、転炉終点の鋼中酸素量が６０
０ｐｐｍ以下である未脱酸の溶鋼を取鍋に出鋼し、
（ｂ）前記未脱酸の溶鋼を収容した取鍋にＡｌまたはＡ
ｌを含むスラグ改質剤を添加することによりスラグ中の
Ｔ．Ｆｅを３ｗｔ％以下とし、（ｃ）前記未脱酸の溶鋼
をＲＨ脱ガス装置において、環流Ａｒ量が１０Ｎｌ／ｍ
ｉｎ・ｔ以上で脱ガスし、鋼中酸素量を１００ｐｐｍ以
下にしてからＡｌにより脱酸し、さらに脱酸後の撹拌エ
ネルギーを２ＷＨ／ｔ以上で溶鋼を攪拌する。As a result of various studies to achieve the above object, the following invention has been made. A first invention is a method for melting high-purity steel, comprising the following steps. (A) The steel is melted in the converter and the oxygen content in the steel at the end point of the converter is 60
Tapping undeoxidized molten steel of 0 ppm or less into a ladle,
(B) Al or A is placed in the ladle containing the undeoxidized molten steel.
By adding a slag modifying agent containing slag, T.I. Fe is set to 3 wt% or less, and (c) the undeoxidized molten steel is subjected to RH degassing in a RH degassing apparatus so that the reflux Ar amount is 10 Nl / m.
The gas is degassed at int or more, the oxygen content in the steel is reduced to 100 ppm or less, then deoxidized with Al, and the molten steel is further stirred at a stirring energy of 2 WH / t or more after deoxidation.
【０００６】まず、転炉の転炉終点の鋼中酸素量を６０
０ｐｐｍ以下と低くして取鍋に出鋼する。次に、この未
脱酸の溶鋼を収容した取鍋にＡｌまたはＡｌを含むスラ
グ改質剤を添加することによりスラグ中のＴ．Ｆｅを３
ｗｔ％以下として溶鋼の再酸化を防止する。更に、この
未脱酸の溶鋼をＲＨ脱ガス装置において、環流Ａｒ量を
１０Ｎｌ／ｍｉｎ・ｔ以上で予め脱ガスし、鋼中酸素量
を１００ｐｐｍ以下にしてからＡｌにより脱酸すると溶
鋼中に発生するアルミナは少なく抑えられる。更に、Ｒ
Ｈ脱ガス装置において撹拌エネルギーを２ＷＨ／ｔ以上
で溶鋼を攪拌すると、溶鋼からアルミナは十分に除去さ
れる。従って、食缶用材料として使用できる高清浄鋼が
溶製できる。First, the amount of oxygen in the steel at the converter end point of the converter is 60
Steel is produced on a ladle with the concentration reduced to 0 ppm or less. Next, Al or a slag modifier containing Al is added to the ladle containing the undeoxidized molten steel to thereby reduce the T.O. Fe 3
Reoxidation of the molten steel is prevented by setting the content to not more than wt%. Further, this undeoxidized molten steel is degassed in advance in a RH degassing apparatus at a reflux Ar amount of 10 Nl / min.t or more, and after the oxygen content in the steel is reduced to 100 ppm or less, and then deoxidized with Al, the molten steel is generated in the molten steel. Alumina is reduced. Further, R
When the molten steel is stirred at a stirring energy of 2 WH / t or more in the H degassing apparatus, alumina is sufficiently removed from the molten steel. Therefore, highly purified steel that can be used as a material for food cans can be melted.
【０００７】第２の発明は、前記未脱酸の溶鋼をＲＨ脱
ガス装置において、環流Ａｒ量が１０Ｎｌ／ｍｉｎ・ｔ
以上で脱ガスし、鋼中酸素量を１００ｐｐｍ以下にする
ためＲＨ脱ガス装置において炭素剤を使用することを特
徴とする請求項１記載の高清浄鋼の溶製方法である。[0007] In a second aspect of the present invention, in the RH degassing apparatus, the undeoxidized molten steel is provided with a reflux Ar amount of 10 Nl / min · t.
The method of claim 1, wherein a carbon agent is used in the RH degassing apparatus to degas and reduce the oxygen content in the steel to 100 ppm or less.
【０００８】Ａｌ添加前の鋼中酸素量が１００ｐｐｍを
超える場合には、Ａｌ添加により発生するアルミナが多
くなるので、ＲＨ脱ガス装置において炭素剤を使用し、
Ａｌ添加前の鋼中酸素量を１００ｐｐｍ以下とし、アル
ミナ介在物を可及的に少なくする。If the oxygen content in the steel before the addition of Al exceeds 100 ppm, the amount of alumina generated by the addition of Al increases, so that a carbon agent is used in the RH degassing apparatus.
The oxygen content in the steel before the addition of Al is set to 100 ppm or less, and alumina inclusions are reduced as much as possible.
【０００９】[0009]
【発明の実施の形態】発明の実施の形態を図１により説
明する。図１に示すように転炉１において酸素量６００
ｐｐｍ以下に精錬された溶鋼を、未脱酸の状態で取鍋２
に出鋼し、さらに溶鋼３表面のスラグ７を改質するた
め、金属Ａｌ、または金属Ａｌを含むスラグ改質剤５を
単独または複合して添加し、スラグ７中のＴ．Ｆｅを３
ｗｔ％以下に低減する。スラグ改質剤５としては例えば
ＣａＯ，ＣａＦ2 ，Ａｌ2 Ｏ3 等を用いることができ
る。An embodiment of the present invention will be described with reference to FIG. As shown in FIG.
The molten steel refined to less than 1 ppm
In order to further improve the slag 7 on the surface of the molten steel 3, metal Al or a slag modifier 5 containing metal Al is added alone or in combination. Fe 3
wt% or less. As the slag modifier 5, for example, CaO, CaF 2 , Al 2 O 3 or the like can be used.
【００１０】転炉終点、即ち出鋼直前の鋼中酸素量
（〔Ｏ〕）が６００ｐｐｍ以下であれば、出鋼後の取鍋
に金属Ａｌ、または金属Ａｌを含むスラグ改質剤５、例
えばアルミ灰（Ａｌ：４０ｗｔ％，Ａｌ2 Ｏ3 ：６０ｗ
ｔ％）等をスラグ７上に添加することにより、スラグ中
のＴ．Ｆｅを３ｗｔ％以下に低減することができる。If the converter end point, that is, the oxygen content ([O]) in the steel immediately before tapping is 600 ppm or less, the ladle after tapping is made of metal Al or a slag modifier 5 containing metal Al, for example, aluminum ash (Al: 40wt%, Al 2 O 3: 60w
t%) or the like on the slag 7, the T.V. Fe can be reduced to 3 wt% or less.
【００１１】しかしながら、転炉終点の鋼中酸素量
〔Ｏ〕が６００ｐｐｍを超えると炉内のスラグ中のＴ．
Ｆｅが高すぎるため、スラグへの金属Ａｌ、または金属
Ａｌを含むスラグ改質剤添加だけではＴ．Ｆｅを３ｗｔ
％以下に低減することはできない。この場合には、何ら
かの方法で溶鋼表面上のスラグ中のＴ．Ｆｅを３ｗｔ％
以下に低減したとしても溶鋼へのアルミナの巻き込み等
があるため好ましくない。However, when the oxygen content [O] in the steel at the end point of the converter exceeds 600 ppm, the T.O.
Since Fe is too high, addition of metal Al or a slag modifier containing metal Al to slag alone results in T.C. Fe 3wt
% Cannot be reduced. In this case, the T.D. Fe 3wt%
Even if it is reduced below, it is not preferable because alumina is involved in the molten steel.
【００１２】次に、Ａｌ添加前の溶鋼の酸素量は可及的
に低いほうが望ましい。そこで、ＲＨ脱ガス装置により
予め炭素による脱酸を行う。この脱酸処理において酸素
量の低下量は溶鋼中に存在する炭素量（〔Ｃ〕）により
決まる。即ち、一定の〔Ｃ〕−〔Ｏ〕濃度積まで低減で
きる。この〔Ｃ〕−〔Ｏ〕濃度積は真空槽内の撹拌力で
きまり、ＲＨ装置の浸漬管からのＡｒ等の不活性ガス量
を溶鋼重量あたり１０Ｎｌ／ｔ以上吹き込むことによ
り、〔Ｃ〕（ｐｐｍ）×〔Ｏ〕（ｐｐｍ) ≦２００００
まで低減できる。Next, it is desirable that the oxygen content of the molten steel before adding Al is as low as possible. Therefore, deoxidation with carbon is performed in advance by the RH degassing device. In this deoxidation treatment, the amount of decrease in the amount of oxygen is determined by the amount of carbon ([C]) present in the molten steel. That is, it can be reduced to a constant [C]-[O] concentration product. The concentration product of [C]-[O] is determined by the stirring force in the vacuum chamber, and the amount of inert gas such as Ar from the immersion tube of the RH device is blown by 10 Nl / t or more per molten steel weight to obtain [C] ( ppm) × [O] (ppm) ≦ 20,000
Can be reduced to
【００１３】従って、必要に応じて炭素剤または炭素含
有合金、例えばコークス、カ−ボネット、高炭素フェロ
マンガン等を合金投入口８から添加することにより、溶
鋼中〔Ｃ〕を２００ｐｐｍ以上とすることにより，溶鋼
中酸素量は１００ｐｐｍ以下まで低減できる．酸素量が
１００ｐｐｍ以下であればその後の脱酸工程にて発生す
るアルミナの量は十分低く、脱酸後の撹拌エネルギ−２
ＷＨ／ｔ以上の環流で十分除去できる。Therefore, if necessary, a carbon agent or a carbon-containing alloy, for example, coke, carbonet, high-carbon ferromanganese or the like is added from the alloy inlet 8 so that the content of [C] in the molten steel is at least 200 ppm. As a result, the oxygen content in the molten steel can be reduced to 100 ppm or less. If the amount of oxygen is 100 ppm or less, the amount of alumina generated in the subsequent deoxidation step is sufficiently low, and the stirring energy after deoxidation-2
It can be sufficiently removed by a reflux of WH / t or more.
【００１４】この時撹拌エネルギ−Ｊは下式で計算す
る。 Ｊ＝ ε×Ｔ ε＝０．００８５×Ｑ×Ｖ／Ｗ Ｑ＝１１．４×Ｇ／３×４Ｄ／３×（ｌｎ（Ｐ１／Ｐ
２））／３At this time, the stirring energy J is calculated by the following equation. J = ε × T ε = 0.0085 × Q × V / W Q = 11.4 × G / 3 × 4D / 3 × (ln (P1 / P
2)) / 3
【００１５】ここで、Ｊ：撹拌エネルギ−（ＷＨ／
ｔ），ε：撹拌動力密度（Ｗ／ｔ） Ｔ：時間（Ｈ），Ｑ：溶鋼環流量（ｔ／ｍｉｎ），Ｖ：
下降流速（ｍ／ｓ） Ｗ：溶鋼量（ｔ），Ｇ：環流ガス流量（ｌ／ｍｉｎ），
Ｄ：浸漬管径（ｍ） Ｐ１：羽口圧力（Ｐａ），Ｐ２：真空槽内圧（Ｐａ）Here, J: stirring energy (WH /
t), ε: stirring power density (W / t) T: time (H), Q: molten steel ring flow rate (t / min), V:
Downflow velocity (m / s) W: amount of molten steel (t), G: reflux gas flow rate (l / min),
D: diameter of immersion tube (m) P1: tuyere pressure (Pa), P2: vacuum tank internal pressure (Pa)
【００１６】この脱酸生成物としてのアルミナの除去と
スラグ中Ｔ．Ｆｅ低減による再酸化防止とを組み合わせ
れば、食缶用材料等の極度に清浄性が要求される材料に
も対応できる高清浄鋼が製造できる。なお、本発明はス
ラグ改質時期が図１では出鋼後であるが、ＲＨ脱ガス開
始前あってもＲＨ脱ガス後（脱炭後）であっても、また
それらの組み合わせで２回行ってもかまわない。The removal of alumina as a deoxidation product and the removal of T.O. When combined with the prevention of re-oxidation by reducing Fe, it is possible to produce high-purity steel that can cope with extremely clean materials such as food can materials. In the present invention, although the slag reforming timing is after tapping in FIG. 1, the slag is reformed twice before starting RH degassing or after RH degassing (after decarburization), or in a combination thereof. It doesn't matter.
【００１７】[0017]
【実施例】本発明の１例を以下に示す。転炉から出鋼さ
れた〔Ｃ〕含有量約０．０４％の２５０ｔの未脱酸溶鋼
に本発明を適用した例を以下に示す。図１に示すように
転炉出鋼後の鋼中酸素量が６００ｐｐｍ以下の溶鋼上の
スラグ上に、スラグ改質剤としてＣａＯ，ＣａＦ2 ，金
属Ａｌ等を添加し、スラグのＴ．Ｆｅを３ｗｔ％以下に
低減した。また、鋼中酸素１００ｐｐｍあたり０．１３
ｋｇ／ｔ以上の金属Ａｌを添加した。DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of the present invention will be described below. An example in which the present invention is applied to a 250-t undeoxidized molten steel having a [C] content of about 0.04%, which is produced from a converter, will be described below. As shown in FIG. 1, CaO, CaF 2 , metal Al, etc. are added as slag modifiers to slag on molten steel having an oxygen content of 600 ppm or less after steel output from the converter, and T.V. Fe was reduced to 3 wt% or less. In addition, 0.13 per 100 ppm of oxygen in steel
At least kg / t of metal Al was added.
【００１８】その後この溶鋼をＲＨ脱ガスに供し，脱炭
を行った．このとき浸漬管からのＡｒガスは１０Ｎｌ／
ｍｉｎ・ｔ以上で，５分以上脱炭した。脱炭途中で、溶
鋼中の酸素量を酸素濃淡電池を利用した酸素メ−タで測
定し、１００ｐｐｍ以上である場合には、炭素剤を添加
し、再度酸素量を測定する。１００ｐｐｍ以上であれば
炭素剤を再度添加するという操作をくり返し、最終的に
１００ｐｐｍ以下とした。Thereafter, the molten steel was subjected to RH degassing to decarburize. At this time, the Ar gas from the dip tube was 10 Nl /
Decarburization was performed for more than 5 minutes at min · t or more. During the decarburization, the amount of oxygen in the molten steel is measured by an oxygen meter using an oxygen concentration battery. If the amount is 100 ppm or more, a carbon agent is added and the amount of oxygen is measured again. If it was 100 ppm or more, the operation of adding the carbon agent again was repeated, and finally the content was made 100 ppm or less.
【００１９】その後脱酸のためのＡｌを添加し、Ａｌ添
加後１０分以上溶鋼を環流させて処理を終了した。環流
処理１０分の撹拌エネルギ−は２ＷＨ／ｔに相当する。
このときの冷間圧延後のコイル中の介在物量を検鏡して
調べ、その結果を製品欠陥指数として示した。この結果
を図７として示す表１の実施例（（Ｎｏ１〜１２）に示
す。このときの条件を再度まとめると下記の通りであ
る。Thereafter, Al for deoxidation was added, and after the addition of Al, the molten steel was refluxed for 10 minutes or more to complete the treatment. The stirring energy for 10 minutes of the reflux treatment corresponds to 2 WH / t.
At this time, the amount of inclusions in the coil after cold rolling was examined by microscopy, and the result was shown as a product defect index. The results are shown in the examples ((Nos 1 to 12)) in Table 1 shown in Fig. 7. The conditions at this time are summarized below.
【００２０】転炉転炉終点酸素量：６００ｐｐｍ以下
で、結果的にスラグ中Ｔ．Ｆｅが３ｗｔ％以下、 ＲＨ環流中のＡｒが１０Ｎｌ／ｍｉｎ以上で、かつ
〔Ｃ〕≧200 ｐｐｍで結果的に溶鋼中酸素量が１００ｐ
ｐｍ以下、 Ａｌ脱酸後の環流時間が１０分以上（撹拌エネルギ−
は２ＷＨ／ｔ以上）であった。Converter Oxygen at the converter end point: 600 ppm or less. When Fe is 3 wt% or less, Ar in the RH reflux is 10 Nl / min or more, and [C] ≧ 200 ppm, the oxygen content in the molten steel is 100 p.
pm or less, reflux time after Al deoxidation is 10 minutes or more (stirring energy
Was 2 WH / t or more).
【００２１】また、比較のため、とは満足したが、
Ｔ．Ｆｅが３ｗｔ％以下を満足できなかったもの（Ｎ
ｏ．１３〜１７）、とは満足したが、ＲＨ装置に
おける脱酸前溶鋼中酸素量が１００ｐｐｍをこえたもの
（Ｎｏ．１８〜２７）、とは満足したが、Ａｌ脱
酸後の環流時間が１０分以上確保できなかったもの（Ｎ
ｏ．２８〜３２）も同時に表１に示した。For comparison, I was satisfied with
T. Fe not satisfying 3 wt% or less (N
o. 13 to 17), the oxygen content in the molten steel before deoxidation in the RH device exceeded 100 ppm (Nos. 18 to 27), but the reflux time after Al deoxidation was 10%. That could not be secured for more than
o. 28-32) are also shown in Table 1.
【００２２】図２に、製品欠陥指数とスラグ中Ｔ．Ｆｅ
の関係を示す。これはいずれもＲＨ装置における脱酸前
酸素量が１００ｐｐｍ以下で、かつ脱酸後の環流時間が
１０分以上のもの（Ｎｏ．１〜１２，１３〜１７）であ
る。スラグ中Ｔ．Ｆｅを３ｗｔ％以下にすれば製品欠陥
は皆無にできることがわかる。FIG. 2 shows the product defect index and T.C. Fe
Shows the relationship. In each case, the amount of oxygen before deoxidation in the RH apparatus is 100 ppm or less and the reflux time after deoxidation is 10 minutes or more (Nos. 1 to 12, 13 to 17). T. in slag It can be seen that if Fe is 3 wt% or less, product defects can be completely eliminated.
【００２３】図３に製品欠陥指数と、ＲＨ装置における
脱酸前酸素量の関係を示す．これはいずれもＴ．Ｆｅが
３ｗｔ％以下かつＲＨ装置における脱酸後の環流時間が
１０分以上のもの（Ｎｏ．１〜１２，１８〜２７）であ
る。ＲＨ装置における脱酸前の酸素量を１００ｐｐｍ以
下にすれば製品欠陥は皆無にできる。FIG. 3 shows the relationship between the product defect index and the amount of oxygen before deoxidation in the RH apparatus. This is T.E. Fe is 3 wt% or less and the reflux time after deoxidation in the RH apparatus is 10 minutes or more (Nos. 1 to 12, 18 to 27). If the amount of oxygen before deoxidation in the RH device is set to 100 ppm or less, no product defects can be caused.
【００２４】図４に製品欠陥指数と、ＲＨ装置における
脱酸後環流時間の関係を示す。これはいずれもＴ．Ｆｅ
が３ｗｔ％以下かつＲＨ装置における脱酸前の酸素量が
１００ｐｐｍ以下のもの（Ｎｏ．１〜１２、２８〜３
２）である。ＲＨ装置における脱酸後の環流時間を１０
分以上とれば製品欠陥は皆無にできる。FIG. 4 shows the relationship between the product defect index and the reflux time after deoxidation in the RH apparatus. This is T.E. Fe
Is 3 wt% or less and the oxygen amount before deoxidation in the RH apparatus is 100 ppm or less (Nos. 1 to 12, 28 to 3
2). The reflux time after deoxidation in the RH device is 10
If it takes more than a minute, there will be no product defects.
【００２５】図５に転炉終点酸素量と、スラグ中Ｔ．Ｆ
ｅの関係を示す。転炉終点酸素量を６００ｐｐｍ以下に
すれば、スラグ中Ｔ．Ｆｅが３ｗｔ％以下にできる。FIG. 5 shows the amount of oxygen at the converter end point and the T.O. F
The relation of e is shown. If the oxygen content at the converter end point is set to 600 ppm or less, T.O. Fe can be reduced to 3 wt% or less.
【００２６】図６に環流Ａｒ量と鋼中〔Ｃ〕とが、脱酸
前における酸素量におよぼす影響を示す。Ａｒ１０Ｎｌ
／ｍｉｎ以上で、かつ〔Ｃ〕が２００ｐｐｍ以上であれ
ば，鋼中酸素量は１００ｐｐｍ以下に低減できる。FIG. 6 shows the effect of the reflux Ar amount and the [C] in the steel on the oxygen amount before deoxidation. Ar10Nl
/ Min or more and if [C] is 200 ppm or more, the oxygen content in steel can be reduced to 100 ppm or less.
【００２７】[0027]
【発明の効果】以上のように本発明によれば、転炉終点
の酸素量を６００ｐｐｍ以下とし、取鍋内のスラグ改質
によりＴ．Ｆｅを３ｗｔ％以下に低減し、さらにＲＨ装
置における環流Ａｒを１０Ｎｌ／ｍｉｎ以上、〔Ｃ〕量
を０．０２ｗｔ％以上とすることにより結果的に〔Ｏ〕
を１００ｐｐｍ以下とすることができる。そこで、Ａｌ
脱酸時に発生するアルミナ量を低減し、さらに脱酸後の
撹拌エネルギ−を２ＷＨ／ｔ以上確保することにより、
製品欠陥のない、食缶等にも適用可能な超高清浄度鋼を
製造することがでる。As described above, according to the present invention, the oxygen content at the end point of the converter is set to 600 ppm or less, and the T.V. Fe is reduced to 3 wt% or less, and the reflux Ar in the RH apparatus is set to 10 Nl / min or more and the [C] amount is set to 0.02 wt% or more, resulting in [O].
To 100 ppm or less. Then, Al
By reducing the amount of alumina generated at the time of deoxidation and securing the stirring energy after deoxidation of 2 WH / t or more,
It is possible to manufacture ultra-high-cleanliness steel that can be used in food cans and the like without product defects.
【図面の簡単な説明】[Brief description of the drawings]
【図１】転炉とＲＨ脱ガス装置を用いて本発明を実施す
る例を説明する概略図である。FIG. 1 is a schematic diagram illustrating an example of implementing the present invention using a converter and an RH degassing device.
【図２】本発明の実施例におけるスラグ中Ｔ．Ｆｅと製
品欠陥指数の関係である。FIG. 2 is a graph showing T.C. It is a relationship between Fe and a product defect index.
【図３】本発明の実施例におけるＲＨ脱酸前酸素量と製
品欠陥指数の関係である。FIG. 3 shows the relationship between the oxygen content before RH deoxidation and the product defect index in Examples of the present invention.
【図４】本発明の実施例におけるＲＨ脱酸後環流時間と
製品欠陥指数の関係である。FIG. 4 shows the relationship between the reflux time after RH deoxidation and the product defect index in Examples of the present invention.
【図５】本発明の実施例における転炉終点酸素量とスラ
グ中Ｔ．Ｆｅの関係である。FIG. 5 is a graph showing the amount of oxygen at the end of the converter and the T.O. It is a relation of Fe.
【図６】本発明の実施例におけるＲＨ脱酸前酸素量に及
ぼす環流Ａｒ量と鋼中〔Ｃ〕の影響を示す図である。FIG. 6 is a graph showing the influence of the amount of reflux Ar and the amount of [C] in steel on the amount of oxygen before RH deoxidation in the example of the present invention.
【図７】本発明の実施例と比較例におけるデ−タを表と
して示す図である。FIG. 7 is a table showing data in Examples of the present invention and Comparative Examples.
１ 転炉 ２ 取鍋 ３ 溶鋼 ４ ＲＨ脱ガス装置 ５ スラグ改質剤 ６ 炭素剤 ７ スラグ ８ 合金投入口 Reference Signs List 1 converter 2 ladle 3 molten steel 4 RH degassing device 5 slag modifier 6 carbon agent 7 slag 8 alloy inlet
─────────────────────────────────────────────────────
────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成９年３月１１日[Submission date] March 11, 1997
【手続補正１】[Procedure amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１４[Correction target item name] 0014
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【００１４】この時撹拌エネルギーＪは下式で計算す
る。 Ｊ＝ε×Ｔ ε＝０．０００８３５×ＱｘＶ２ ／Ｗｇ Ｑ＝１１．４×Ｇ１／３ ×Ｄ４／３ ×（１ｎ（Ｐ１／Ｐ
２））１／３ At this time, the stirring energy J is calculated by the following equation. J = ε × T ε = 0.000835 × Qx V 2 / W g Q = 11.4 × G 1/3 × D 4/3 × (1n (P1 / P
2)) 1/3
【手続補正２】[Procedure amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】００１５[Correction target item name] 0015
【補正方法】変更[Correction method] Change
【補正内容】[Correction contents]
【００１５】ここで、Ｊ：撹拌エネルギー（ＷＨ／
ｔ），ε：撹拌動力密度（Ｗ／ｔ） Ｔ：時間（Ｈ），Ｑ：溶鋼環流量（ｔ／ｍｉｎ），Ｖ：
下降流速（ｍ／ｓ）Ｗｇ ：溶鋼量（ｔ），Ｇ：環流ガス流量（１／ｍｉ
ｎ），Ｄ：浸漬管径（ｍ） Ｐ１：羽口圧力（Ｐａ），Ｐ２：真空槽内圧（Ｐａ）Here, J: stirring energy (WH /
t), ε: stirring power density (W / t) T: time (H), Q: molten steel ring flow rate (t / min), V:
Downflow velocity (m / s) Wg : molten steel amount (t), G: reflux gas flow rate (1 / mi)
n), D: diameter of immersion tube (m) P1: tuyere pressure (Pa), P2: vacuum tank internal pressure (Pa)
───────────────────────────────────────────────────── フロントページの続き (72)発明者 吉岡 敬二 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 杉山 晋一 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 村井 剛 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 (72)発明者 松野 英寿 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Keiji Yoshioka 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Shinichi Sugiyama 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Sun (72) Inventor Tsuyoshi Murai 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Nihon Kokan Co., Ltd. (72) Hidetoshi Matsuno 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Inside the corporation
Claims (2)
清浄鋼の溶製方法。 （ａ）転炉で鋼を溶製し、転炉終点の鋼中酸素量が６０
０ｐｐｍ以下である未脱酸の溶鋼を取鍋に出鋼し、
（ｂ）前記未脱酸の溶鋼を収容した取鍋にＡｌまたはＡ
ｌを含むスラグ改質剤を添加することによりスラグ中の
Ｔ．Ｆｅを３ｗｔ％以下とし、（ｃ）前記未脱酸の溶鋼
をＲＨ脱ガス装置において、環流Ａｒ量が１０Ｎｌ／ｍ
ｉｎ・ｔ以上で脱ガスし、鋼中酸素量を１００ｐｐｍ以
下にしてからＡｌにより脱酸し、さらに脱酸後の攪拌エ
ネルギーを２ＷＨ／ｔ以上で溶鋼を攪拌する。1. A method for melting high-purity steel, comprising the following steps: (A) The steel is melted in the converter and the oxygen content in the steel at the end point of the converter is 60
Tapping undeoxidized molten steel of 0 ppm or less into a ladle,
(B) Al or A is placed in the ladle containing the undeoxidized molten steel.
By adding a slag modifying agent containing slag, T.I. Fe is set to 3 wt% or less.
After degassing at more than in · t, reducing the oxygen content in the steel to 100 ppm or less, deoxidizing with Al, and further stirring the molten steel at a stirring energy after deoxidation of 2 WH / t or more.
いて、環流Ａｒ量が１０Ｎｌ／ｍｉｎ・ｔ以上で脱ガス
し、鋼中酸素量を１００ｐｐｍ以下にするためＲＨ脱ガ
ス装置において炭素剤を使用することを特徴とする請求
項１記載の高清浄鋼の溶製方法。2. An RH degassing device for degassing the undeoxidized molten steel at a reflux Ar amount of 10 Nl / min · t or more and a carbon agent in the RH degassing device to reduce the oxygen content in the steel to 100 ppm or less. The method for melting high-purity steel according to claim 1, wherein:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03144597A JP3282531B2 (en) | 1997-01-31 | 1997-01-31 | Melting method of high clean steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP03144597A JP3282531B2 (en) | 1997-01-31 | 1997-01-31 | Melting method of high clean steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10219337A true JPH10219337A (en) | 1998-08-18 |
| JP3282531B2 JP3282531B2 (en) | 2002-05-13 |
Family
ID=12331459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP03144597A Expired - Fee Related JP3282531B2 (en) | 1997-01-31 | 1997-01-31 | Melting method of high clean steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3282531B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100910496B1 (en) | 2002-12-21 | 2009-07-31 | 주식회사 포스코 | Method for Manufacturing Extra-Low Carbon Steel |
| KR101008159B1 (en) | 2003-11-17 | 2011-01-13 | 주식회사 포스코 | Method for Refining Low Carbon Molten Steel |
| JP2012077354A (en) * | 2010-10-01 | 2012-04-19 | Jfe Steel Corp | Method for melting/preparing low carbon aluminum killed steel excellent in cleanliness |
| JP2016138307A (en) * | 2015-01-27 | 2016-08-04 | 新日鐵住金株式会社 | Method for production of superclean steel |
| CN106282489A (en) * | 2015-05-28 | 2017-01-04 | 鞍钢股份有限公司 | A kind of double refining method improving Cleanliness of Molten Steel |
| CN110747313A (en) * | 2019-12-03 | 2020-02-04 | 冷水江市高科窑炉耐火材料有限公司 | Preparation method of novel top slag modifier |
-
1997
- 1997-01-31 JP JP03144597A patent/JP3282531B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100910496B1 (en) | 2002-12-21 | 2009-07-31 | 주식회사 포스코 | Method for Manufacturing Extra-Low Carbon Steel |
| KR101008159B1 (en) | 2003-11-17 | 2011-01-13 | 주식회사 포스코 | Method for Refining Low Carbon Molten Steel |
| JP2012077354A (en) * | 2010-10-01 | 2012-04-19 | Jfe Steel Corp | Method for melting/preparing low carbon aluminum killed steel excellent in cleanliness |
| JP2016138307A (en) * | 2015-01-27 | 2016-08-04 | 新日鐵住金株式会社 | Method for production of superclean steel |
| CN106282489A (en) * | 2015-05-28 | 2017-01-04 | 鞍钢股份有限公司 | A kind of double refining method improving Cleanliness of Molten Steel |
| CN110747313A (en) * | 2019-12-03 | 2020-02-04 | 冷水江市高科窑炉耐火材料有限公司 | Preparation method of novel top slag modifier |
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| Publication number | Publication date |
|---|---|
| JP3282531B2 (en) | 2002-05-13 |
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