JPH05230516A - Melting method for extra-low-carbon steel - Google Patents
Melting method for extra-low-carbon steelInfo
- Publication number
- JPH05230516A JPH05230516A JP4031863A JP3186392A JPH05230516A JP H05230516 A JPH05230516 A JP H05230516A JP 4031863 A JP4031863 A JP 4031863A JP 3186392 A JP3186392 A JP 3186392A JP H05230516 A JPH05230516 A JP H05230516A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- steel
- concn
- decarburization
- bath surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、極低炭素鋼の溶製方法
に関するものである。極低炭素鋼の溶製は、転炉におい
て脱炭および脱燐を行った後、ＲＨ真空脱ガス装置また
はＤＨ装置を用いて所定の極低炭素濃度まで脱炭および
脱酸を行うのが通例である。そして脱炭および脱酸を、
より低濃度域まで迅速に行うことが、鋼の材質特性やAl
2O3 系介在物による表面欠陥防止のために望ましい。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for melting ultra low carbon steel. In the melting of ultra-low carbon steel, it is customary to decarburize and dephosphorize in a converter and then decarburize and deoxidize to a predetermined ultra-low carbon concentration using an RH vacuum degassing device or DH device. Is. And decarburization and deoxidation,
It is possible to quickly perform to the lower concentration range, because of the material properties of steel and Al.
It is desirable to prevent surface defects due to 2 O 3 inclusions.
【０００２】[0002]
【従来の技術】脱酸の効率化に関し、鉄と鋼（1990）の
第1932〜1939頁には、取鍋浴上に存在するスラグを還元
してスラグ中の酸化鉄や酸化マンガンによる鋼浴の再酸
化を防止する手法が開示されている。しかしながら、こ
の手法の実施には、取鍋浴上のスラグの量および組成を
迅速に実測することが難しいため、還元が不安定にな
り、例えば、過剰に還元剤を投入した場合には、この還
元剤が鋼中の溶存酸素と反応して脱炭に必要な酸素の不
足を招き、また、スラグの還元によって脱燐した燐が再
び溶鋼中に戻る、いわゆる復燐が発生する等の問題が残
る。2. Description of the Related Art Regarding the efficiency of deoxidation, Iron and Steel (1990), pages 1932 to 1939, slag existing on a ladle bath is reduced to produce a steel bath containing iron oxide or manganese oxide in the slag. A method for preventing the reoxidation of the is disclosed. However, in carrying out this method, it is difficult to measure the amount and composition of the slag on the ladle bath quickly, so that the reduction becomes unstable. For example, when excessive reducing agent is added, this The reducing agent reacts with the dissolved oxygen in the steel, causing a shortage of oxygen necessary for decarburization, and the phosphorus dephosphorized by the reduction of slag returns to the molten steel again, so-called re-phosphorization occurs. Remain.
【０００３】また、極低炭素鋼の溶製に当たっては、例
えば材料とプロセス（1990）第168〜171 頁に報告され
ているように、極低炭素領域における脱炭の停滞現象
も、解決しなければならない課題である。In the melting of ultra-low carbon steel, the stagnation phenomenon of decarburization in the ultra-low carbon region must be solved, as reported in, for example, Materials and Processes (1990), pages 168-171. This is an issue that must be addressed.
【０００４】[0004]
【発明が解決しようとする課題】この発明は、上記の諸
問題を解消し、高品質かつ安価な極低炭素鋼を量産し得
る方法について提案することを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and propose a method capable of mass-producing high quality and inexpensive ultra low carbon steel.
【０００５】[0005]
【課題を解決するための手段】発明者らは、炭素、酸
素、燐および硫黄の不純物を除去する各手法の組み合わ
せを適正化することによって、上記の目的を成就できる
ことを見出し、この発明を完成した。The present inventors have found that the above object can be achieved by optimizing a combination of respective methods for removing impurities of carbon, oxygen, phosphorus and sulfur, and completed the present invention. did.
【０００６】すなわちこの発明は、高炉からの溶銑に含
まれるＰおよびＳを、それぞれ0.05wt％以下，0.01wt％
以下に抑制する予備処理工程、上記予備処理工程を経た
溶銑を転炉にてＣ：0.02〜0.1 wt％の範囲まで脱炭する
工程、脱炭終了後の溶鋼を収容した取鍋内浴面上に、還
元剤やフラックスを添加することにより、その浴面上に
形成させるスラグの組成を、FeO およびMnO の合計濃度
が５wt％以下になるように調整する工程、この取鍋から
ＲＨ真空脱ガス装置の真空槽内に導入する溶鋼浴面上に
酸化性ガスを吹きつけることにより、該溶鋼の酸素濃度
および温度を調整した後、含水素粉体を吹きつけて溶鋼
のＣ濃度を所定範囲に調整し、その後真空槽内に脱酸剤
を添加して溶鋼の脱酸を行う工程、を経ることを特徴と
する極低炭素鋼の溶製方法である。That is, according to the present invention, P and S contained in the hot metal from the blast furnace are 0.05 wt% or less and 0.01 wt%, respectively.
Pretreatment process to be suppressed below, process of decarburizing the hot metal that has undergone the above pretreatment process to a range of C: 0.02 to 0.1 wt% in the converter, on the ladle bath containing the molten steel after decarburization A process of adjusting the composition of the slag formed on the bath surface so that the total concentration of FeO and MnO is 5 wt% or less by adding a reducing agent and flux to the RH vacuum degassing from this ladle. The oxygen concentration and temperature of the molten steel are adjusted by blowing an oxidizing gas onto the molten steel bath surface introduced into the vacuum tank of the apparatus, and then hydrogen-containing powder is blown so that the C concentration of the molten steel falls within a predetermined range. It is a method for melting ultra-low carbon steel, which comprises a step of adjusting and then deoxidizing molten steel by adding a deoxidizing agent into the vacuum chamber.
【０００７】[0007]
【作用】以下、図１に示す工程図に基づいて、本発明方
法の詳細について説明する。 (1) 溶銑予備処理工程 まず、予備処理工程として、高炉からの溶銑に脱燐およ
び脱硫を施すことが不可欠である。すなわち、この予備
処理工程によって、CaO などの副原料の原単位を鋼の溶
製プロセス全体で減少し得るばかりか、転炉吹錬で生じ
たスラグ中のP2O5が少なくなるため、スラグ改質やＲＨ
真空脱ガス処理などの２次精錬においてP2O5の還元によ
る溶鋼への復燐の懸念が解消するからである。The details of the method of the present invention will be described below with reference to the process chart shown in FIG. (1) Hot Metal Pretreatment Process First, as a pretreatment process, it is indispensable to dephosphorize and desulfurize the hot metal from the blast furnace. In other words, this pretreatment process not only reduces the unit consumption of auxiliary raw materials such as CaO in the entire steel melting process, but also reduces the P 2 O 5 in the slag generated by converter blowing, which reduces the slag. Reforming and RH
This is because in secondary refining such as vacuum degassing, there is no concern about phosphorus reconstitution into molten steel due to reduction of P 2 O 5 .
【０００８】(2) 転炉工程 次に転炉では主に脱炭を行う。ここで転炉における吹止
めＣ濃度を0.02〜0.1％としたのは、0.02％未満ではス
ラグ中の酸化鉄濃度が高くなり過ぎて転炉耐火物に悪影
響を及ぼすこと、スラグ改質が不安定になること、そし
て、次工程のＲＨ真空脱ガス処理時にCaO 等を上吹きラ
ンスから吹付けても、CaO とFeO 等のスラグ成分との滓
化がすみやかに進行してスラグによる再酸化が生じ、脱
酸が効率よく進まなくなること、などの理由による。一
方、Ｃ濃度が0.1 ％をこえると、次工程のＲＨ真空脱ガ
ス処理における脱炭での酸素濃度が低くなり過ぎて迅速
な脱炭が達成できない。なお、この低炭素域まで脱炭す
る際は、副次的にわずかの脱燐も生じる。(2) Converter Process Next, the converter mainly decarburizes. Here, the blowout C concentration in the converter is set to 0.02 to 0.1% because if the concentration is less than 0.02%, the iron oxide concentration in the slag becomes too high and the converter refractory is adversely affected, and the slag reforming is unstable. In addition, even if CaO or the like is sprayed from the upper blowing lance during the RH vacuum degassing process in the next step, the slag components of CaO and FeO and the like rapidly progress to form reoxidation by the slag. The reason is that deoxidation does not proceed efficiently. On the other hand, if the C concentration exceeds 0.1%, the oxygen concentration in the decarburization in the RH vacuum degassing process in the next step becomes too low, and rapid decarburization cannot be achieved. When decarburizing to this low carbon region, a slight amount of dephosphorization is secondarily generated.
【０００９】(3) スラグ改質工程 続いて脱炭後の溶鋼を出湯した取鍋においてスラグの改
質を行なうが、ここではスラグ成分を（FeO ）＋（MnO
）≦５％に調整することが、スラグからの再酸化を防
止する上で肝要である。(3) Slag reforming step Subsequently, the slag is reformed in a ladle from which molten steel after decarburization is tapped. Here, the slag component is (FeO 2) + (MnO 2)
) ≦ 5% is essential to prevent reoxidation from slag.
【００１０】(4) ＲＨ真空脱ガス処理工程 次いで、上記溶鋼をＲＨ真空脱ガス処理にて、所定の炭
素濃度および酸素濃度とする。すなわち、上記までの工
程で得られた炭素濃度および溶存酸素濃度、さらには、
溶鋼温度に応じて、ＲＨ真空脱ガス装置の真空槽に配置
した上吹きランスから、真空槽内の鋼浴面に酸素または
酸素を含む酸化性ガスを吹付ける。ここで溶存酸素濃度
が不足している場合は、吹付けた酸素は鋼中酸素源とな
って脱炭速度の上昇に寄与し、また、一部の酸素は脱炭
で生じたCOガスを燃やしてCO2 となり、その際の燃焼熱
を溶鋼に伝える。この酸化性ガスの吹付けによって、Ｒ
Ｈ真空脱ガス処理に供する溶鋼の酸素濃度および処理温
度を制御することができるため、前工程の転炉およびス
ラグ改質工程での成分および温度の厳密な管理は不要と
なる。(4) RH Vacuum Degassing Treatment Step Next, the molten steel is subjected to RH vacuum degassing treatment so as to have a predetermined carbon concentration and oxygen concentration. That is, the carbon concentration and the dissolved oxygen concentration obtained in the above steps, further,
Depending on the molten steel temperature, oxygen or an oxidizing gas containing oxygen is blown onto the steel bath surface in the vacuum tank from an upper blowing lance arranged in the vacuum tank of the RH vacuum degassing apparatus. If the dissolved oxygen concentration is insufficient here, the sprayed oxygen serves as an oxygen source in the steel and contributes to an increase in the decarburization rate, and some oxygen burns the CO gas generated by decarburization. Becomes CO 2 and transfers the heat of combustion to molten steel. By spraying this oxidizing gas, R
Since it is possible to control the oxygen concentration and the treatment temperature of the molten steel to be subjected to the H vacuum degassing treatment, it is not necessary to strictly control the components and the temperature in the converter and the slag reforming process in the preceding process.
【００１１】さらに、極低炭素領域までの脱炭には、上
記の上吹きランスから、Ca(OH)2,Mg(OH)2, ミョウバン
などの水素を含む粉体を真空槽内の鋼浴面に吹付ける。
すると、例えばCa(OH)2 を吹きつけた場合は、Ca(OH)2
→CaO ＋２Ｈ＋Ｏ の反応によって生じた鋼中水素Ｈ
が、２Ｈ→Ｈ2 となって鋼浴面近傍に発生する際に、反
応界面積の増加を伴うため、Ｃ＋Ｏ→ＣＯの脱炭反応が
促進される。従って、従来は、極低炭素領域で発生して
いた脱炭の停滞を打破することができ、よって、精錬限
界炭素濃度までの低下を迅速に実施できる。Further, for decarburization up to the extremely low carbon region,
From the above blowing lance, Ca (OH)2, Mg (OH)2Alum
A powder containing hydrogen such as is sprayed onto the steel bath surface in the vacuum chamber.
Then, for example, Ca (OH)2When sprayed, Ca (OH)2
→ CaO ＋2H+O In steel produced by the reaction ofH
But 2H→ H2 When it occurs in the vicinity of the steel bath surface,
As the field area increases,C+O→ CO decarburization reaction
Be promoted. Therefore, conventionally, it occurs in the extremely low carbon region.
It was possible to overcome the stagnation of decarburization, which was the reason for refining.
It is possible to quickly reduce the boundary carbon concentration.
【００１２】そして、所定の極低炭素濃度に調整したの
ちは、引き続いて真空槽内にAlなどの還元剤を添加して
溶鋼の脱酸をはかり、さらに、成分調整等も行なって所
望の成分の極低炭素鋼とする。After adjusting to a predetermined extremely low carbon concentration, subsequently, a reducing agent such as Al is added to the vacuum chamber to deoxidize the molten steel, and further the components are adjusted to obtain the desired components. Of ultra low carbon steel.
【００１３】[0013]
(1) 溶銑予備処理工程 高炉からトピードカー内に出銑した溶銑300 ｔに、浸漬
ランスからフラックスを吹き込んで脱燐および脱硫をそ
の間に脱燐スラグの除滓を挟んで行った。ここで脱燐フ
ラックスには酸化鉄：25〜35kg／ｔ，生石灰：８〜15kg
／ｔおよびCaF2：１〜２kg／ｔを、また、脱硫フラック
スには（30％CaO ＋70％CaCO3 ）：６〜８kg／ｔを、そ
れぞれ用いた。この溶銑予備処理工程によって、Ｐ：0.
11〜0.12％およびＳ：0.02〜0.03％からＰ：0.035 〜0.
05％およびＳ：0.005 〜0.009 ％とした。(1) Hot Metal Pretreatment Step 300 g of hot metal tapped from the blast furnace into the tope car was blown with flux from an immersion lance to perform dephosphorization and desulfurization, with the dephosphorized slag slag interposed therebetween. Here, for dephosphorization flux, iron oxide: 25-35 kg / t, quick lime: 8-15 kg
/ T and CaF 2 : 1 to 2 kg / t, and (30% CaO + 70% CaCO 3 ): 6 to 8 kg / t were used for the desulfurization flux. By this hot metal pretreatment process, P: 0.
11-0.12% and S: 0.02-0.03% to P: 0.035-0.
05% and S: 0.005-0.009%.
【００１４】(2) 転炉工程 次いで、 300ｔの溶銑を、上底吹き転炉で吹錬し、吹止
め時のＣ含有量を0.02〜0.10％、および溶鋼温度を1610
〜1630℃とした。なお、上吹きＯ2 流量は700Nm3/min
および底吹き不活性ガス流量は20〜30Nm3/min で操業し
た。(2) Converter process Next, 300 t of hot metal is blown in an upper-bottom blowing converter, the C content at the time of blowing is 0.02 to 0.10%, and the molten steel temperature is 1610.
It was set to ~ 1630 ° C. The flow rate of top-blown O 2 is 700 Nm 3 / min
And the bottom blown inert gas flow rate was 20 to 30 Nm 3 / min.
【００１５】(3) スラグ改質工程 上記転炉から取鍋に出鋼中に金属Alを40％含みCaO を主
成分とするフラックスを、溶鋼１ｔ当たり1.3 〜1.5kg
添加し、取鍋内鋼浴上のスラグ中のFeO とMnOとの合計
濃度を1.3 〜5.0 ％に調整した。このとき鋼中のＯ濃度
は100 〜550ppmおよび溶鋼温度は1590〜1610℃であっ
た。(3) Slag reforming step 1.3 to 1.5 kg per ton of molten steel containing 40% of metallic Al in the steel output from the above converter and containing CaO as a main component in the ladle.
The total concentration of FeO and MnO in the slag on the steel bath in the ladle was adjusted to 1.3 to 5.0%. At this time, the O concentration in the steel was 100 to 550 ppm, and the molten steel temperature was 1590 to 1610 ° C.
【００１６】(4) ＲＨ真空脱ガス処理工程 次に、ＲＨ真空脱ガス処理開始２分後に、真空槽の上か
ら下へ垂直に挿入した水冷ランスをその先端が浴面から
1.5 〜2.0 ｍの位置で固定し、このランスからＯ2 ガス
を30〜50Nm3/min の流量で吹きつけ、吹きつけ後のＯ濃
度を500 〜600ppmおよび溶鋼温度を1595〜1610℃とし
た。(4) RH vacuum degassing process step Two minutes after the start of the RH vacuum degassing process, a water cooling lance vertically inserted from the top to the bottom of the vacuum chamber was inserted from the bath surface to the tip.
After fixing at a position of 1.5 to 2.0 m, O 2 gas was blown from this lance at a flow rate of 30 to 50 Nm 3 / min, the O concentration after blowing was set to 500 to 600 ppm, and the molten steel temperature was set to 1595 to 1610 ° C.
【００１７】その後、浴面から1.5 〜1.8 ｍの位置の上
記ランスから、Arガス（２〜３Nm3/min ）をキャリアガ
スとして、Ca(OH)2 粉を30〜60kg/minの吹きつけ速度で
供給し、Ｃ：５〜７ppm およびＯ：450 〜550 ppm とし
た。さらに、還元剤としてAlを1.2 〜1.4kg/t 添加し、
引き続き、溶鋼の脱ガス処理を８〜10分間行ってＲＨ脱
ガス処理を終了した。上記の処理を経た溶鋼の成分組成
は、Ｃ：５〜７ppm ，Al：0.03〜0.04％，Ｐ：0.024 〜
0.030 ％，Ｓ：0.004 〜0.008 ％および溶鋼温度：1570
〜1580℃であった。Then, from the above-mentioned lance at a position of 1.5 to 1.8 m from the bath surface, using Ar gas (2 to 3 Nm 3 / min) as a carrier gas, Ca (OH) 2 powder was sprayed at a rate of 30 to 60 kg / min. And C: 5 to 7 ppm and O: 450 to 550 ppm. Furthermore, 1.2 to 1.4 kg / t of Al is added as a reducing agent,
Subsequently, the molten steel was degassed for 8 to 10 minutes to complete the RH degassing. The composition of the molten steel that has undergone the above treatment is C: 5 to 7 ppm, Al: 0.03 to 0.04%, P: 0.024 to
0.030%, S: 0.004 to 0.008% and molten steel temperature: 1570
It was ~ 1580 ° C.
【００１８】また、比較例として、上記した一連の工程
の一部を省略するか、または発明範囲外の条件で工程を
経た処理によって得られた溶鋼の成分組成についても調
査し、その結果を上記の実施例に併せて表１に示した。Further, as a comparative example, the composition of molten steel obtained by omitting a part of the above-mentioned series of steps or by carrying out the steps under conditions outside the scope of the invention was also investigated, and the results are shown above. The results are shown in Table 1 together with the examples.
【００１９】[0019]
【表１】 [Table 1]
【００２０】[0020]
【発明の効果】この発明によれば、高純度で清浄度の高
い極低炭素鋼を、迅速に、しかも経済的に大量生産する
ことができる。According to the present invention, extremely low carbon steel having high purity and high cleanliness can be mass-produced rapidly and economically.
【図１】この発明の方法を示す工程図である。FIG. 1 is a process drawing showing a method of the present invention.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 桐原 理 千葉県千葉市川崎町１番地 川崎製鉄株式 会社技術研究本部内 (72)発明者 大宮 茂 岡山県倉敷市水島川崎通１丁目（番地な し） 川崎製鉄株式会社水島製鉄所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Riri Kirihara 1 Kawasaki-cho, Chiba-shi, Chiba Inside the Technical Research Division, Kawasaki Steel Co., Ltd. (72) Inventor Shigeru Omiya 1-chome, Mizushima Kawasaki-dori, Kurashiki-shi, Okayama ) Kawashima Steel Works Mizushima Steel Works
Claims (1)
Ｓを、それぞれ0.05wt％以下，0.01wt％以下に抑制する
予備処理工程、(2) 上記予備処理工程を経た溶銑を転炉
にてＣ：0.02〜0.1 wt％の範囲まで脱炭する工程、(3)
脱炭終了後の溶鋼を収容した取鍋内浴面上に、還元剤や
フラックスを添加することにより、その浴面上に形成さ
せるスラグの組成を、FeO およびMnO の合計濃度が５wt
％以下になるように調整する工程、(4) この取鍋からＲ
Ｈ真空脱ガス装置の真空槽内に導入する溶鋼浴面上に酸
化性ガスを吹きつけることにより、該溶鋼の酸素濃度お
よび温度を調整した後、含水素粉体を吹きつけて溶鋼の
Ｃ濃度を所定範囲に調整し、その後真空槽内に脱酸剤を
添加して溶鋼の脱酸を行う工程、を経ることを特徴とす
る極低炭素鋼の溶製方法。1. A pretreatment process for suppressing P and S contained in the hot metal from the blast furnace to 0.05 wt% or less and 0.01 wt% or less, respectively. (2) The hot metal subjected to the pretreatment process is converted into a converter. Decarburization to C: 0.02 to 0.1 wt% range at (3)
After the decarburization is completed, the composition of the slag formed on the bath surface in the ladle containing the molten steel by adding a reducing agent or flux is such that the total concentration of FeO and MnO is 5 wt.
%, The process of adjusting to be less than (4) R from this ladle
The oxygen concentration and temperature of the molten steel are adjusted by blowing an oxidizing gas onto the molten steel bath surface introduced into the vacuum tank of the H vacuum degasser, and then hydrogen-containing powder is blown to blow the C concentration of the molten steel. To a predetermined range, and then adding a deoxidizing agent into the vacuum chamber to deoxidize the molten steel.
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4031863A JP3002593B2 (en) | 1992-02-19 | 1992-02-19 | Melting method of ultra low carbon steel |
| US07/993,388 US5304231A (en) | 1991-12-24 | 1992-12-18 | Method of refining of high purity steel |
| DE69227014T DE69227014T2 (en) | 1991-12-24 | 1992-12-21 | Process for refining very pure steel |
| EP92121682A EP0548868B1 (en) | 1991-12-24 | 1992-12-21 | Method of refining of high purity steel |
| KR1019920025275A KR960009168B1 (en) | 1991-12-24 | 1992-12-23 | Method of refining of high purity steel |
| BR9205155A BR9205155A (en) | 1991-12-24 | 1992-12-23 | METHOD OF REFINING A HIGH PURITY STEEL |
| CA002086193A CA2086193C (en) | 1991-12-24 | 1992-12-23 | Method of refining of high purity steel |
| CN92115273A CN1061381C (en) | 1991-12-24 | 1992-12-24 | Method of refining of high purity steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4031863A JP3002593B2 (en) | 1992-02-19 | 1992-02-19 | Melting method of ultra low carbon steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05230516A true JPH05230516A (en) | 1993-09-07 |
| JP3002593B2 JP3002593B2 (en) | 2000-01-24 |
Family
ID=12342892
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4031863A Expired - Fee Related JP3002593B2 (en) | 1991-12-24 | 1992-02-19 | Melting method of ultra low carbon steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3002593B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8313553B2 (en) | 2008-08-04 | 2012-11-20 | Nucor Corporation | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment |
| US8523977B2 (en) | 2011-01-14 | 2013-09-03 | Nucor Corporation | Method of desulfurizing steel |
| JP2014025111A (en) * | 2012-07-27 | 2014-02-06 | Jfe Steel Corp | Method for producing high cleanliness steel |
| CN105483501A (en) * | 2014-09-19 | 2016-04-13 | 鞍钢股份有限公司 | Smelting method of phosphorus-containing ultra-low carbon steel |
| CN111518988A (en) * | 2020-05-11 | 2020-08-11 | 首钢集团有限公司 | Method for modifying ultra-low carbon steel refining slag |
| US11047015B2 (en) | 2017-08-24 | 2021-06-29 | Nucor Corporation | Manufacture of low carbon steel |
-
1992
- 1992-02-19 JP JP4031863A patent/JP3002593B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8313553B2 (en) | 2008-08-04 | 2012-11-20 | Nucor Corporation | Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment |
| US8523977B2 (en) | 2011-01-14 | 2013-09-03 | Nucor Corporation | Method of desulfurizing steel |
| JP2014025111A (en) * | 2012-07-27 | 2014-02-06 | Jfe Steel Corp | Method for producing high cleanliness steel |
| CN105483501A (en) * | 2014-09-19 | 2016-04-13 | 鞍钢股份有限公司 | Smelting method of phosphorus-containing ultra-low carbon steel |
| US11047015B2 (en) | 2017-08-24 | 2021-06-29 | Nucor Corporation | Manufacture of low carbon steel |
| CN111518988A (en) * | 2020-05-11 | 2020-08-11 | 首钢集团有限公司 | Method for modifying ultra-low carbon steel refining slag |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3002593B2 (en) | 2000-01-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5092245B2 (en) | Denitrification method for molten steel | |
| CN112226578A (en) | Rare earth addition control method for high-strength rare earth girder steel | |
| CN115595397B (en) | Accurate nitrogen control method for nitrogen-containing high-strength steel | |
| JP5386825B2 (en) | Method for melting Mn-containing ultra-low carbon steel | |
| JP3428628B2 (en) | Stainless steel desulfurization refining method | |
| JP3002593B2 (en) | Melting method of ultra low carbon steel | |
| CN103225009A (en) | Method for producing high-cleanness steel | |
| JP4687103B2 (en) | Melting method of low carbon aluminum killed steel | |
| JP3172550B2 (en) | Manufacturing method of high cleanliness steel | |
| JPH09235611A (en) | Production of extra-low sulfur pure iron having high cleanliness | |
| JP2912963B2 (en) | Slag reforming method as desulfurization pretreatment | |
| KR100388239B1 (en) | Method for producing low sulfer, low carbon steel using eaf-vtd process | |
| JPH06207212A (en) | Production of high creanliness extra-low carbon steel of extremely low s | |
| KR970004990B1 (en) | Decarburizing method of stainless steel | |
| JP3594757B2 (en) | Melting method for high purity high Ni molten steel | |
| KR20030089955A (en) | The method of decreasing nitrogen in deoxidized molten steel | |
| JPH04318118A (en) | Production of steel with extremely low carbon and extremely low sulfur | |
| JP7302749B2 (en) | Molten iron dephosphorization method | |
| JP7255639B2 (en) | Molten steel desulfurization method and desulfurization flux | |
| WO2022259806A1 (en) | Molten steel denitrification method and steel production method | |
| KR101008087B1 (en) | A method for desulfurizing at vacuum tank degasser | |
| JPH04268012A (en) | Production of clean steel | |
| JPH07316637A (en) | Melting method of dead-soft steel with extra-low sulfur content | |
| JP3684445B2 (en) | Manufacturing method of high purity high Ni steel | |
| JPH10102135A (en) | Method for desulfurizing molten steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20071112 Year of fee payment: 8 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20081112 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091112 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101112 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111112 Year of fee payment: 12 |
|
| LAPS | Cancellation because of no payment of annual fees |