JPS6010086B2 - Steel manufacturing method - Google Patents
Steel manufacturing methodInfo
- Publication number
- JPS6010086B2 JPS6010086B2 JP613180A JP613180A JPS6010086B2 JP S6010086 B2 JPS6010086 B2 JP S6010086B2 JP 613180 A JP613180 A JP 613180A JP 613180 A JP613180 A JP 613180A JP S6010086 B2 JPS6010086 B2 JP S6010086B2
- Authority
- JP
- Japan
- Prior art keywords
- steel
- converter
- blowing
- oxygen blowing
- molten steel
- 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.)
- Expired
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Description
本発明は連続鋳造工程において気泡を発生させることな
く、リムド鋼相当鋼を製造する方法に関する。
リムド鋼は精錬過程で故意に脱酸を殆んど行わず、造塊
時に多量のCOガスを発生させ、その気泡によるリミン
グアクションにより凝固界面の不純物を洗い流して製造
される鋼種である。
これを連続鋳造法の如く凝固の進行とともに藤片を引抜
移動させる方法によって製造せんとする場合はも気泡の
発生が激し過ぎると鋳型内の湯動きが活発となる為にち
又は未凝固港鋼の深部からの突鞠現象が起こる為に危険
であり「気泡の発生か弱くても連続鋳造時の凝固速度が
早いため〜表面近傍に微細な気泡がトラップされて製品
においてピソホール欠陥が生じるという問題が存在する
ためtリムド鋼の連続鋳造化は殆んど行われていない。
従って連続鋳造適用鋼種としては「AとあるいはSiに
より脱駿を行ったキルド鋼及びセミキルド鋼に限定され
るがトSiキルド鋼は勿論のこともAとキルド鋼、A〆
−Sjキルド鋼もA〆によるスラグ中「あるいは耐火物
中のSi02の環元によって溶鋼中の〔Sj〕が増加し
もこのようなSiの存在によって深絞り性の劣化〜Zn
メッキ密着性の劣化〜テンパーカラーの発生〜カラー鋼
板腰折れ等の品質上の問題が発生しも穴拡げ性の劣化ト
冷延率の制限等鋼材加工上の問題も生じていた。また特
にAとキルド鋼〜Aで町Siキルド鋼の場合は「A〆2
03クラス夕の存在による銭片品費の劣化の池トAそ脱
酸生成物による取鍋ノズルあるいはタンディッシュノズ
ルの語り等操業上の間題ト更にはAそ添加費が高いとい
うコスト上の問題が存在する。このようにAク又はSj
によって脱醗したキルド鋼あるいはセミキルド鋼はA〆
あるいはS竃の存在に起因する欠点があるためも用途上
の制約は避け得ずt上述の欠点がない品質のものが要求
される場合には造魂分塊法によるリムド鋼が適用されて
いるのが実情である。しかしながらし造塊分塊法に比べ
て歩留りが高くも生産性の良い連続鋳造法の適用鋼種拡
大は時代の趨勢であり「Siを殆んど含まずtAそ含有
量の低い所謂リムド相当鋼種の連続鋳造化も当然に要望
されトこれに応えていくつかの試みがなされている。
前述のような深絞り性の劣化等に欠点をさげるためには
も〔Sj〕はなるべく低い方が好ましいが「少くともリ
ムド鋼として認められる0。020%以下にする必要が
ある。
またA多添加コスト上、並びに耐火物中のSj02の還
元によって生じる溶鋼中の〔Sj〕の増加及び取鋼ノズ
ル又は夕ソディッシュゾズルの詰りを防止する為にばち
T,〔Aぞ〕についても低い方が好ましい。しかしなが
ら、例えば熱延鋼板等の鋼中窒素の固定の必要な鋼種に
おいては「T.〔A夕〕は0.010〜0020%必要
とし、袷延鋼板で箱競鈍する場合等はト連続鋳造時の気
泡の発生を防止するのに必要なAぞ添加量でよい等「用
途によって異なるのでT8〔Aで〕は0.020%以下
であればリムド鋼相当品として十分な値を示していると
いえる。而してこのような値以下にT。〔A夕〕「〔S
i〕を抑制する場合には〜当然脱酸不足となりtCO気
泡が発生すると考えられる。一般に溶融金属中において
気泡が発生する条件は「気泡の内圧が大気圧ト気泡の位
置における漆湯の静水圧「及び凝集力によって気泡が受
ける圧力の和よりも大であることである。
換言すれば〜漆鋼中の成分の反応によって生成されるC
OもN2「日2等のガス圧の総和がも前記大気圧〜静水
圧、凝集力による圧力の総和よりも小さければ気泡は発
生しない。ところでN2ガス「日2ガスの分圧はCOガ
スに比べて小さいので「気泡の発生を防止するにはCO
ガスの発生を抑えなければならないが「前述のピンホー
ル欠陥は鋳型内の薄い凝固殻に小気泡がトラップされた
結果生じたものであるので静水圧は極めて小さくもまた
凝集力によって気泡が受ける圧力も1柵&程度の気泡で
は小さいので〜結局気泡発生の防止の為にはCOガス圧
を大気圧すなわち1気圧以下にすれば良いということに
なる。COガスは港鋼中のCと自由○とが‘1ー式の如
く反応して生成したものであり〜C十G=C○(g)…
…州{1ー但し〜C三溶鋼中のC
Q軍溶鋼中の自由O
C○(g)ミCOガス
平衡状態ではC濃度及び自由○濃度とCOガスの圧力P
coとの間には平衡定数をKとすると■式の関係が成立
する。
Pc。
〔C〕x〔○〕こK………{2}
槌しも〔C〕き溶鋼中のC濃度
〔Q〕:溶鋼中の自由○濃度
この平衡状態ではも自由〔Q〕を7の風以下に抑制する
場合は「〔C〕が043%程度の高濃度であっても畔c
oが1気圧以下となる。
従って凝固が進行している状態においては「 自由〔0
〕7敬仰以下に抑制する場合は、当然にCOガスの発生
は抑えることができる。そうすると〔SI〕、T.〔A
〆〕の低し、溶鋼を連続鋳造法にて鋳造せんとする場合
は、Si「 A〆による脱駿に頼ることなく、別の方法
で脱酸を行って自由The present invention relates to a method for producing steel equivalent to rimmed steel without generating bubbles in a continuous casting process. Rimmed steel is a type of steel that is manufactured by intentionally performing almost no deoxidation during the refining process, generating a large amount of CO gas during ingot formation, and using the rimming action of the bubbles to wash away impurities at the solidification interface. If this is manufactured by a method such as continuous casting, in which the pieces are pulled out and moved as solidification progresses, if the generation of air bubbles is too intense, the movement of the molten metal in the mold will become active, resulting in It is dangerous because the bulging phenomenon occurs from deep within the steel, and even if the bubbles are weak, the solidification rate during continuous casting is fast, causing the problem of fine bubbles being trapped near the surface and causing pisohole defects in the product. Because of this, continuous casting of T-rimmed steel is rarely carried out.
Therefore, the types of steel that can be used for continuous casting are limited to killed steel and semi-killed steel that have been desilted with A or Si, but of course Si killed steel, A and killed steel, A〆-Sj killed steel as well as A [Sj] in the molten steel increases due to the ring element of Si02 in the refractory or the Si02 in the refractory, but the presence of such Si causes deterioration of deep drawability.
Quality problems such as deterioration of plating adhesion, occurrence of temper color, and buckling of colored steel sheets occurred, as well as problems in steel material processing such as deterioration of hole expandability and limitations on cold rolling rate. In addition, in particular, in the case of A and killed steel ~ A and town Si killed steel, “A〆2
03 There are operational issues such as deterioration in product costs due to the presence of oxidation products, problems with ladle or tundish nozzles due to deoxidation products, and cost issues such as high additive costs. exists. In this way Aku or Sj
Killed steel or semi-killed steel that has been deliquified by the process has disadvantages due to the presence of A or S furnaces, so restrictions in terms of use cannot be avoided. The reality is that rimmed steel is applied using the soul agglomeration method. However, the current trend is to expand the range of steel types to which the continuous casting method, which has a higher yield and better productivity than the ingot blooming method, is being applied. Naturally, continuous casting is also desired, and several attempts have been made in response to this.In order to reduce the disadvantages such as the deterioration of deep drawability as mentioned above, it is preferable that [Sj] be as low as possible. ``It is necessary to reduce the amount to at least 0.020% or less, which is accepted as rimmed steel.In addition, due to the cost of adding A, and the increase in [Sj] in molten steel caused by the reduction of Sj02 in the refractory, and the increase in [Sj] in the steel withdrawal nozzle or In order to prevent clogging of the sodish nozzle, it is preferable that the drumsticks T and [A] be lower. However, for example, in steel types such as hot-rolled steel plates that require fixation of nitrogen in the steel, "T. 0.010 to 0.020% is required, and when box dulling rolled steel sheets, etc., the amount of A required to prevent the generation of bubbles during continuous casting may be sufficient. If [at A] is 0.020% or less, it can be said that it shows a sufficient value as a product equivalent to rimmed steel.
i], it is thought that deoxidation will naturally become insufficient and tCO bubbles will be generated. Generally, the condition for the generation of bubbles in molten metal is that the internal pressure of the bubble is greater than the sum of the atmospheric pressure, the hydrostatic pressure of the lacquer bath at the bubble location, and the pressure exerted on the bubble by cohesive force. C produced by reaction of components in lacquered steel
If the sum of the gas pressures of O and N2 gases is smaller than the sum of atmospheric pressure, hydrostatic pressure, and pressure due to cohesive force, bubbles will not be generated.By the way, the partial pressure of N2 gas Because it is relatively small, ``To prevent bubbles from forming, CO
Gas generation must be suppressed, but ``the pinhole defects mentioned above are the result of small bubbles being trapped in the thin solidified shell inside the mold, so the hydrostatic pressure is extremely small, but the pressure exerted on the bubbles by cohesive force is Since a bubble of about 1 bar is small, in the end, in order to prevent bubble generation, it is sufficient to reduce the CO gas pressure to atmospheric pressure, that is, 1 atmosphere or less. It is produced by reacting as shown in the equation '1-~C0G=C○(g)...
...state {1-However, C3 C in molten steel Q free O in molten steel C ○ (g) Mi In CO gas equilibrium state, C concentration, free ○ concentration and pressure P of CO gas
If the equilibrium constant is K, then the relationship of equation (2) holds true between co and co. Pc. [C] If the concentration of [C] is as high as 0.43%,
o becomes 1 atm or less. Therefore, in the state where coagulation is progressing, "Freedom [0
] If the temperature is suppressed to 7 degrees or less, the generation of CO gas can naturally be suppressed. Then [SI], T. [A
When casting molten steel using a continuous casting method, it is possible to deoxidize using another method without relying on deoxidation using Si.
〔0〕をコントロールすれば良いこ
とになる。このような観点に立って脱酸を行う銭片製造
方法としては、特関昭53−?3422、侍関昭弘−9
3618が公知である。
これらは転炉精錬後真空脱ガス処理を行い、〔C〕と自
由〔○〕とを低下せしめた後、A夕(前者)あるいはA
〆とTi(後者)添加による脱酸を行う方法であり、こ
れにより〔SO〜T.〔A夕〕の低い港鋼の連続鋳造が
可能である。しかしながらこれらの方法では、未脱酸状
態で「 しかも溶鋼中の自由All you have to do is control [0]. From this point of view, the method for manufacturing coin coins that performs deoxidation is Tokuseki 53-? 3422, Samurai Seki Akihiro-9
3618 is known. These are subjected to vacuum degassing treatment after converter refining to reduce [C] and freedom [○].
This is a method of deoxidizing by adding Ti and Ti (the latter). Continuous casting of low port steel is possible. However, in these methods, "free oxidation in molten steel"
〔0〕が高い状態で真空に
引く為にスプラッシュが発生しやすく〜更に真空設備の
排気能力が大きいことが要求される。このスプラッシュ
等により炉壁に付着した地金が真空処理時に溶鋼中に脱
落する為「自由Splash is likely to occur because the vacuum is drawn in a state where [0] is high, and furthermore, the vacuum equipment is required to have a large evacuation capacity. Due to this splash, the base metal adhering to the furnace wall falls into the molten steel during vacuum treatment, so it is called "Freedom".
〔0〕のコントロールが難しい等の欠点
も有する。また真空処理中の温度低下が大きい為、転炉
の出鋼温度を高くせざるを得ず、これにより転炉工程で
の脱燐が不足し、また転炉耐火物の溶損が大きいという
問題がある。更に真空処理に長時間を要するためt工程
上大きな制約を受け〜 また真空処理設備費及び真空処
理のランニングコストが高いという欠点も存在する。本
発明は斯かる事情に鑑みてなされたものであって、真空
処理を施さないにも拘らず、気泡を発生させることなく
連続鋳造が可能であるリムド鋼相当品を製造する方法を
提供することを目的とする。
本発明に係る製鋼法は、{1}転炉(純酸素上吹転炉、
底吹転炉も又は所謂複合吹錬炉等をいう)において少く
とも〔P〕を成品に要求される成分濃度以下になすべく
吹錬しt【2にの吹錬した溶湯を溶傷容器に出鋼するこ
とにより転炉スラグの除去を図った後、‘3’更に該港
湯を、裕面下よりガスを導入し得るようにした転炉(例
えば所謂複合吹銭炉)に出鋼し、該転炉において酸素吹
銭を行わないか「あるいは造蓬剤を実質的に添加するこ
となく酸素吹銭し〜【4}酸素吹銭を行う場合は該酸素
吹銭中及び/又は酸素吹鎌後に「 また酸素吹錬を行わ
ない場合は転炉に装入後にt鋼浴面下よりガスを導入し
て糟梓精錬を行い「風連続鋳造機にてスラブ又はブルー
ムを鋳造するような場合は澄梓精鎌中、縄幹精錬後にお
ける転炉から取鍋への出鋼中、又は出鋼後の少くともい
ずれか一の期間においてAそ添加による脱酸を行い「自
由It also has drawbacks such as difficulty in controlling [0]. In addition, because the temperature drop during vacuum treatment is large, the tapping temperature of the converter has to be raised, which results in insufficient dephosphorization in the converter process, and there is also a problem of large melting loss of the converter refractories. There is. Furthermore, since the vacuum treatment requires a long time, there are significant restrictions on the process.There is also a drawback that the vacuum treatment equipment cost and the running cost of the vacuum treatment are high. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for producing a product equivalent to rimmed steel that can be continuously cast without generating bubbles even though it is not subjected to vacuum treatment. With the goal. The steel manufacturing method according to the present invention includes {1} converter (pure oxygen top-blown converter,
In a bottom blowing converter (also referred to as a so-called composite blowing furnace), blow the molten metal in step 2 to a melting container to reduce the concentration of [P] to at least the required concentration of the finished product. After removing the converter slag by tapping, the port water is further tapped into a converter (for example, a so-called compound blowing furnace) that allows gas to be introduced from below the surface. , either do not carry out oxygen blowing in the converter or carry out oxygen blowing without substantially adding a forming agent. ``In addition, if oxygen blowing is not performed, gas is introduced from below the steel bath surface after charging into the converter, and kasuzu refining is performed.``When slabs or blooms are cast using a continuous wind casting machine.'' During Sumizusa Seikama, during tapping from the converter to the ladle after rope refining, or at least during one of the periods after tapping, deoxidation is carried out by adding A-so.
〔0〕が70肌以下〜T.〔Aと〕が0.020%以
下、〔Sま〕が不可避的含有量である溶鋼を溶製し、該
溶鋼を連続鋳造機により鋳造するものであり、また連続
鋳造機にてビレットを鋳造するような場合は、‘1}〜
■の ‐処理を行った後、(5′)要すれば蝿洋精錬中
「渡洋精錬後における転炉から取鍋への出鋼中、又は出
鋼後の少くともいずれか一の期間においてAと添加によ
る脱酸を行い「自由[0] 70 skin or less ~ T. Molten steel containing 0.020% or less of [A and] and an unavoidable content of [S] is produced, and the molten steel is cast using a continuous casting machine, and a billet is cast using a continuous casting machine. In such cases, '1}~
(5') If necessary, during the offshore refining, during the tapping from the converter to the ladle after the overseas refining, or at least during one of the periods after the tapping, Deoxidizes by adding
〔0〕が100〜180脚「(S量
〕が不可避的含有量である溶鋼を溶製し「(6)該溶鋼
を連続鋳造機により鋳造するに際して、該連続鋳造機を
構成する鋳型内溶鋼中にAそを添加して脱酸処理を行い
、鋳型内溶鋼の自由[0] is 100 to 180 rods "(S amount) is melted steel having an unavoidable content" (6) When casting the molten steel with a continuous casting machine, the molten steel in the mold constituting the continuous casting machine By adding A solute into the mold and deoxidizing it, the molten steel is released in the mold.
〔0〕を70脚以下、T.〔A〆〕
を0.020%以下、〔Sj〕を不可避的含有量となら
しめるものである。
以下本発明に係る製鋼法を上記番号順に処理工程を追っ
て詳述する。
(1ー 本発明では先ず、転炉において少くとも〔P〕
を成品に要求される成分濃度以下になすべく吹錬するが
「 これは従来と同機の方法により「例えば石灰系の造
連剤を使用して酸素吹鏡を行う。
また造律剤としては、ソーダ灰等のアルカリ金属炭酸塩
を使用すれば脱燐等に効果があるが、次順のスラグレス
吹銭又は鷹梓精錬において〔C〕、自由[0] less than 70 legs, T. [A〆]
is 0.020% or less, and [Sj] is made to be an unavoidable content. Hereinafter, the steel manufacturing method according to the present invention will be explained in detail, following the processing steps in the order of the numbers mentioned above. (1- In the present invention, first, in the converter, at least [P]
Oxygen blowing is carried out to reduce the concentration of ingredients to below the required concentration of the finished product. The use of alkali metal carbonates such as soda ash is effective for dephosphorization, but in the following slagless Fukisen or Takaazusa Refining [C], free
〔0〕のコント
ロールを容易にする為に「 この通常転炉吹鎌における
終点〔C〕は0.05%以上であるように吹止めるのが
好ましい。けだし終点〔C〕が0.05%未満である場
合は、吹止時の自由In order to easily control [0], it is preferable to stop blowing so that the end point [C] in this normal converter blowing sickle is 0.05% or more. If , the freedom at the end of the blowout
〔0〕が高くなり過ぎて、後述する
裕面下からガスを導入する雛梓精錬によりC脱醗を行っ
ても、十分に自由[0] becomes too high, and even if C is removed by Hinazusa Refining, which introduces gas from below the surface, it will not be sufficiently free.
〔0〕を低下し得ず、更に後工程のA
〆脱酸にて所定の値に自由〔0)をコントロールするこ
とが難しい為である。すなわちこの通常転炉吹銭では〔
Si〕「〔P〕「〔S〕等の調整、特に脱燐を主目的と
して行い、〔P〕が成品に要求される成分濃度以下に迄
脱燐された状態で吹止めるのであるが「 この際に〔C
〕が0.05%未満に迄脱炭されないように送酸速度、
吹込圧力、造連剤添加量等を考慮する。そして本発明に
よる製造対象がリムド鋼代替品であるという性質に鑑み
ればト成品のP〜 S濃度は共に0.030%以下が好
ましいので〜 この通常転炉吹銭によって得られる熔湯
の〔P〕、〔S〕は共に0。030%以下とする。
なお〜特に低硫鋼又は低燐鋼を必要とする場合は、この
通常転炉吹銭に先立ち脱硫「脱燐等の予備処理を行えば
よい。
(2} このようにして通常転炉吹鎌にて得た落陽を後
述するスラグレス吹錬又は濃枠精錬の工程に供する為、
通常転炉吹銭にて生成している転炉スラグの除去を図る
。
このスラグカットをより完全に行う為に、該総湯を溶
湯容器に一端出湯する。即ち通常転炉吹鍵を行った転炉
から〜溶湯客器たる取鍋に港湯を一端出濠しも而して後
「後述するスラグレス吹鎌又は損梓精錬を行う綾合吹鏡
炉等の転炉に菱入する所謂liレードル法によりスラグ
除去を行う。通常転炉吹銭を行った転炉から取鋼に出湯
する際のスラグカット方法としてはも出湯開始時に、転
炉の炉壁上部に通常設置してある孔状の出湯口に〜ボロ
布もスケール等の詰め物をする方法がある。また出湯末
期のスラグ流出防止方法としてはも耐火物性の球状物(
スラグボール)を出湯口上に落下させ出湯口を閉塞する
スラグボール法〜ズトッパーにて出湯口を閉塞するスラ
グスドッパー法へ溶濠面上に浮も、ている出湯口近辺の
スラグに生石灰粉を添加してスラグを固化させ出湯口か
らスラグが流出しないようにする生石灰粉法等が公知で
ある。更に出湯開始時及び出湯末期のスラグ流出を共に
防止できる方法としても出湯口にスライディングバルブ
を設置してもスライディングバルブの開閉により出湯を
制御する出湯口スライディングゲート法も知られている
。また敬鍋から次工程の複合吹銭炉等の転炉に出湯する
際には〜取鍋底部に設置されたスライディングバルブ又
はストッパーの開閉によめ出湯を制御してスラグカット
を行う方法がある。要するにこれらの方法をリレードル
の過程で適宜採決すればよい。また場合によっては通常
吹鎌を行った転炉内も若しくは取鍋内の落陽面上のスラ
グし又はスラグレス吹錘若しくは蝿梓精錬を行う転炉内
に混入したスラグをスラグドラッカ等により排除するよ
うな処置をとることとしてもよい。‘3} このように
して実質的にスラグを排除された溶湯を複合吹鎌炉等の
浴面下よりガスを導入し得るようにした転炉に装入し、
前述の通常転炉吹錬にて〔C〕が所定の値に低下してい
る場合は酸素吹鎌することなく後述する縄群精錬を行う
。
また〔C〕調整をする必要がある場合は造蓬剤を実質的
に添加することなく酸素吹鍵を行うがもこの酸素吹錬則
ちスラグレス吹鎌においてはも〔C〕調整則ち脱炭のみ
を配慮すればよくちまたスラグが実質的に存在しないの
で吹鋸中にスラグから溶鋼への酸素の供繋台がなく「酸
素吹鍵によって終点〔C〕と終点自由[0] cannot be lowered, and further A in the subsequent process
This is because it is difficult to control freedom [0] to a predetermined value during deoxidation. In other words, in this normal converter coin,
Si] "[P]" [S] etc. are adjusted, especially for dephosphorization, and the blow-off is performed after [P] is dephosphorized to below the component concentration required for the product. At the same time [C
] is not decarburized to less than 0.05%,
Consider the blowing pressure, the amount of linking agent added, etc. In view of the nature of the product to be manufactured by the present invention as a rimmed steel substitute, it is preferable that the P to S concentrations of the finished product are both 0.030% or less. ] and [S] are both 0.030% or less. If low sulfur steel or low phosphorus steel is particularly required, preliminary treatment such as desulfurization or dephosphorization may be performed prior to the normal converter blowing. (2) In this way, the normal converter blowing sickle In order to use the fallen sun obtained in the slagless blowing or dark frame refining process described later,
The aim is to remove converter slag that is normally produced in converter slag. In order to perform this slag cutting more completely, the total molten metal is once tapped into a molten metal container. In other words, from the converter where converter blowing is normally performed, the port water is discharged into a ladle, which serves as a molten metal container, and then a slag-less blowing sickle or an ayago blowing mirror furnace, etc., which performs the slagless blowing kiln, which will be described later, is used. The slag is removed by the so-called LI ladle method, which is inserted into the converter.Normally, the slag is cut when the molten metal is tapped from the converter that has been blown into the converter. There is a method of filling the hole-shaped tap hole that is usually installed at the top with rags or scales.Also, as a method to prevent the slag from flowing out at the end of the taping stage, there is a method of filling the hole-shaped tap hole that is usually installed at the top with refractory spherical material (
From the slag ball method in which a slag ball (slag ball) is dropped onto the tap to block the tap to the slag dopper method in which the tap is closed with a stopper, quicklime powder is added to the slag near the tap that floats on the surface of the moat. A quicklime powder method and the like are known, in which the slag is solidified to prevent it from flowing out from the tap hole. Furthermore, as a method for preventing slag outflow both at the start of tapping and at the end of tapping, there is also known a sliding gate method in which a sliding valve is installed at the tap and the tap is controlled by opening and closing the sliding valve. In addition, when pouring hot water from a ladle to a converter such as a composite blowing bath furnace in the next step, there is a method of cutting slag by controlling the pouring of hot water by opening and closing a sliding valve or a stopper installed at the bottom of the ladle. In short, these methods can be adopted as appropriate during the relay process. In addition, in some cases, slag mixed in the inside of the converter where blowing sickle is normally performed or on the falling surface of the ladle, or the slag mixed into the converter where slagless blowing spindle or fly azusa refining is performed, may be removed using a slag draker, etc. You may take appropriate action. '3} The molten metal from which slag has been substantially removed in this way is charged into a converter, such as a composite blow sickle furnace, in which gas can be introduced from below the bath surface,
If [C] has decreased to a predetermined value in the above-mentioned normal converter blowing, the rope group refining described later is performed without oxygen blowing. In addition, if it is necessary to make [C] adjustment, oxygen blowing is carried out without substantially adding a forming agent; In addition, since there is virtually no slag, there is no oxygen supply stand from the slag to the molten steel during the blow saw, and the end point [C] and the end point are freely connected by the oxygen blowing key.
〔0〕とを高精度
でコントロールできる。{43 次にこの酸素吹銭を行
う場合は酸素吹鎌(スラグレス吹銭)中及びノ又は酸素
吹鎌後に〜 また酸素吹鏡を行わない場合は該転炉に袋
入後にも浴面下よりArガス等の不活性ガスを導入して
鋼俗を糟梓せしめる。
これにより酸素吹鏡中の灘洋にあっては酸素吹鎌末期の
渡洋力の低下を補し、ト酸素吹鎌による脱炭を効率良く
行わしめ〜溶鋼中の自由[0] can be controlled with high precision. {43 Next, when performing this oxygen blowing, during and after the oxygen blowing sickle (slugless blowing coin) ~ Also, if oxygen blowing is not performed, from below the bath surface even after placing the bag in the converter. An inert gas such as Ar gas is introduced to weaken the steel. This compensates for the decline in crossing power at the end of the oxygen blowing sickle phase in Nadayo during the oxygen blowing mirror, allowing efficient decarburization with the oxygen blowing sickle.
〔0〕の増加を防止し〜鷹梓精
錬のみを行う場合にあってはC脱酸を促進させる。この
C脱酸は櫨梓用のガスとしてAて等の不活性ガスを使用
する場合にも鋼浴中の気泡におけるCOガス分圧が不活
性ガスに希釈されて低くなるためも港鋼中のCと自由Q
との{1}式による反応が生じて起こるむのである。す
なわち0}式により生成したCO気泡を不活性ガスによ
り希釈してCOガス分圧を下げ〜{1}式によるCOの
生成を促進させるか「あるいはAr気泡を溶鋼中に多量
に分布させ{1字式の反応により生成するCOをA鴇気
泡中に希釈混合して漆鋼中から排出せしめて{i}式の
反応を促進させ、溶鋼中の目高[0] is prevented from increasing, and when only Takaazusa refining is performed, C deoxidation is promoted. This C deoxidation is also possible when an inert gas such as A is used as the gas for the steel bath because the CO gas partial pressure in the bubbles in the steel bath is diluted by the inert gas and becomes low. C and freedom Q
This occurs due to the reaction according to the formula {1}. In other words, the CO bubbles generated by the formula 0} are diluted with an inert gas to lower the CO gas partial pressure ~ the generation of CO is promoted by the formula {1}, or the Ar bubbles are distributed in large quantities in the molten steel {1}. The CO generated by the reaction in the lacquered steel is diluted and mixed into the A bubbles to be discharged from the lacquered steel to promote the reaction in the {i} type.
〔0〕を低下させるもの
である。この櫨幹精錬により溶鋼中の〔C〕と自由〔Q
〕と平衡するぞc。は1気圧以下となる。雛枠カーxの
導入は「通常の転炉を使用し「該転炉の鋼浴中に灘梓ガ
ス用のランスを挿入して行ってもよいがも第富図に示す
ように転炉の炉底に羽□亀を設瞳してなる榎合吹鎌炉を
用いてもこの羽口電から蝿梓ガスを導入し鋼俗を縄拝す
るのが最も効率がよい。
またこの羽口は炉壁下部に設置しても同様の効果がある
ことは勿論である。損梓ガスはAへXr「Xe等の不活
性ガスが好ましい。酸素吹鏡時の櫨梓力の低下を補う場
合にはCOあるいはC02でもよいが「COはC脱酸時
のCOガス分圧を下げ得ず、またC02はCOと02と
に分解してCO及び02を発生するのでやはり自由〔0
〕を低下し得ず「共にC脱駿時には好ましくない。N2
でもよいが「溶鋼中のNの吸収が問題となる鋼種では好
ましくない。また酸素吹錬中にN2を使用したときは〜
途中から舟等のN2を含まないガスに変更するか「又は
吹銭後にAで等のN2を含まないガスで蝿拝を行って脱
窒を行うとよい。更に酸素吹鎌中の澄洋ガスとしては「
02を使用してもよい。またこれらのガスを紙合せて使
用することも可能である。ガス流量は溶鋼lt(トン)
当り0,0刈彼ノ分以上必要である。0.0洲あノ分未
満であると蝿杵効果が少〈、脱醗速度が遅い為、処理時
間が長くなり、処理中の湊鋼温度の低下が問題となる。
上述の如き健梓精錬を、スラグレス吹銭に併用して行う
スラグレス複合吹錬においては、酸素吹鏡末期の鷹枠力
の低下が補われ「脱炭が効率良く行われるので「溶鋼中
の自由[0] is lowered. Through this refining, [C] and free [Q] in the molten steel
] will be in equilibrium with c. is less than 1 atm. The introduction of the hatch frame car x can be done by using a normal converter and inserting a lance for Nada Azusa gas into the steel bath of the converter, but as shown in Fig. Even if you use an Enokiai blowing sickle furnace with a feather pupil installed at the bottom of the hearth, it is most efficient to introduce the fly gas from this tuyere and use it to feed the steel.Also, this tuyere It goes without saying that the same effect can be obtained even if it is installed at the bottom of the furnace wall.The oxidation gas is preferably an inert gas such as Xr or Xe. may be CO or CO2, but ``CO cannot lower the partial pressure of CO gas during C deoxidation, and CO2 decomposes into CO and 02 to generate CO and 02, so it is still free [0
] cannot be lowered.
However, it is not preferable for steel types where absorption of N in molten steel is a problem.Also, when N2 is used during oxygen blowing...
It is better to change to a gas that does not contain N2, such as a boat, or perform denitrification by using a gas that does not contain N2, such as A, after blowing. teeth"
02 may also be used. It is also possible to use a combination of these gases. Gas flow rate is molten steel lt (tons)
It takes more than his share of 0.0 harvest per hit. If it is less than 0.0 min, the fly-pull effect will be small, and since the deliquification rate is slow, the treatment time will be prolonged, and a drop in the temperature of the minato steel during treatment will become a problem. In slagless combined blowing, in which Kenazusa refining as described above is combined with slagless blowing, the decrease in the frame force at the end of the oxygen blowing process is compensated for, and decarburization is performed efficiently.
〔0〕が徒らに増加することがなのは前述したと
おりである。
またスラグが実質的に存在しないので鷹梓時のスラグか
ら綾鋼中への酸素の供給がなく、麓梓ガスの流量調節に
より吹止時の自由As mentioned above, [0] may increase unnecessarily. In addition, since there is virtually no slag, there is no supply of oxygen from the slag to the twill steel during the taka-azusa process, and the flow rate of the taka-azusa gas can be adjusted to provide freedom during blow-off.
〔0〕を高精度でコントロールできる
。第2図は横軸に終点〔C〕をトまた縦軸に終点自由〔
0〕をとり、通常の純酸素上吹吹錬(LD)を行った場
合の終点〔C〕と終点自由[0] can be controlled with high precision. Figure 2 shows the end point [C] on the horizontal axis and the free end point [C] on the vertical axis.
0] and perform normal pure oxygen top blowing (LD), the end point [C] and the free end point
〔0〕との関係を斜線領域で
「 また前掲{1}の通常転炉吹銭(終点〔C〕と終点
自由The relationship with [0] is shown in the shaded area.
〔0〕との関係を△で示した)後、スラグレス複合
吹錬(終点〔C〕と終点自由After the relationship with [0] is indicated by △), slagless composite blowing (end point [C] and end point free
〔0〕との関係を○で示し
た)を行った場合の効果を白抜矢符で示したグラフであ
る。一般に酸素吹込みにより脱炭は進行するが、溶鋼中
の自由〔0)は逆に増加する。従って終点における〔C
〕×This is a graph in which the effect when the relationship with [0] is indicated by a circle is shown by an open arrow. Generally, decarburization progresses by oxygen injection, but the freedom [0] in molten steel increases. Therefore, at the end point [C
〕×
〔0〕が小さい程、その精錬法は優れていることに
なるが、スラグレス榎合吹鎌の場合は通常の吹鏡(LD
)に比して自由The smaller [0] is, the better the refining method is.
) free compared to
〔0〕が低目に推移し、同一〔C〕に対
し後工程で脱酸処理することを要する[0] continues to be low, and it is necessary to deoxidize the same [C] in the subsequent process.
〔0〕が少いとい
う利点がある。また図中実線でPco:1気圧「160
000の場合の平衡状態における〔C〕とIt has the advantage of having less [0]. In addition, the solid line in the figure indicates Pco: 1 atm "160"
[C] in the equilibrium state in the case of 000 and
〔0〕との関
係を示した。なお実際はC02も生成するので「この実
線はPco十Pco2=1気圧の場合の平衡状態におけ
る〔C〕と自由The relationship with [0] is shown. In fact, C02 is also generated, so this solid line is the free line between [C] in the equilibrium state when Pco + Pco2 = 1 atm.
〔0〕との関係であるが、〔C〕が0.
1%の場合におけるC02はCO+C02の2%以下と
騒く徴量なので無視できる。さて本発明とは異り造連剤
を使用して酸素吹鍵に縄洋精錬を併用した榎合吹鏡の場
合の終点〔C〕と終点自由Regarding the relationship with [0], [C] is 0.
In the case of 1%, CO2 can be ignored since it is less than 2% of CO+C02. Now, unlike the present invention, the end point [C] and the free end point in the case of the Enoki blowing mirror, which uses a condensing agent and combines the oxygen blowing key with rope and western refining.
〔0〕との関係を食で示した
。図から明らかなように、このような榎合吹鏡の場合で
も通常吹錬に比して〔C〕×The relationship with [0] is shown by eclipses. As is clear from the figure, even in the case of this type of Enoki blowing mirror, compared to normal blowing, [C] ×
〔0〕は大幅に低く、Pc
。
=1気圧における平衡状態に近いが、本発明の如きスラ
グレス後合吹銭の場合(0印)は更に〔C〕×[0] is significantly lower, Pc
. = Close to the equilibrium state at 1 atm, but in the case of a slugless post-agifukisen like the one of the present invention (marked 0), it is further [C] ×
〔0〕が
低く、平衡するPc。は1気圧以下となっている。これ
は縄梓時におけるスラグから溶鋼への酸素供給がないた
め、鷹梓効果が減殺されないことを示している。このよ
うにスラグレス複合吹錬は精錬法として極めて優れたも
のであるといえる。さて「 スラグレス複合吹銭の後に
雛梓精錬を行った結果を第2図中に・で示した。
更にPco=0.5気圧及びPc。=0.3気圧の場合
に平衡する〔C〕と自由〔0)との関係を夫々破線及び
1点鎖線で示した。図から明らかな如く〜瀦梓による脱
炭及び脱酸効果は著しく、擁拝する鋼俗の溶鋼面上にス
ラグが実質的に存在しないために櫨枠効果は損われず「
溶鋼中の〔C〕、自由[0] is low and Pc is balanced. is less than 1 atm. This indicates that the hawking effect is not diminished because there is no oxygen supply from the slag to the molten steel during the hawking process. In this way, slagless composite blowing can be said to be an extremely excellent refining method. Now, the results of Hinaazusa refining after slagless composite blowing coins are shown in Figure 2. Furthermore, equilibrium occurs when Pco = 0.5 atm and Pc = 0.3 atm [C]. The relationship with freedom [0] is shown by a broken line and a dashed-dotted line, respectively.As is clear from the figure, the decarburization and deoxidation effects of slag are remarkable, and slag is substantially deposited on the surface of the molten steel. Because there is no “Hashih frame” effect, the
[C] in molten steel, free
〔0〕と平衡するPc。が0.3
気圧程度に迄C脱酸が進行している。従って後述するA
〆脱醗処理にて添加するAそ量は著しく小量でよいこと
になる。なお通常転炉吹鍵で〔C〕が0.05%程度と
なるように吹止めた場合は、その後のスラグレス穣合吹
錬及び櫨梓精錬により〔C〕が0.02%程度になる迄
脱炭できる。‘5},(5),(6)次に該漆鋼を連続
鋳造機にて鋳造するに際し「Aク添加による脱酸を行い
連続鋳造機を構成する鋳型内の未凝固熔鋼中の自由〔0
〕を7の剛以下に迄低下せしめる。
この工程においてビレット連続鋳造機のように取鍋又は
タンディッシュのノズル径が小さい(15側め以下)場
合は、A〆脱酸生成物A〆203によるノズル詰りが起
きやすい。具体的にはAそ添加による脱酸にて得た取鍋
、タンディッシュ内の港鋼中の自由Pc in equilibrium with [0]. is 0.3
C deoxidation progresses to about atmospheric pressure. Therefore, A
This means that the amount of A added in the final demelting process can be extremely small. In addition, when blowing is stopped so that [C] is about 0.05% with a normal converter blowing key, the subsequent slagless slag-less blowing and slag refining are performed until [C] becomes about 0.02%. Can be decarburized. '5}, (5), (6) Next, when the lacquered steel is cast in a continuous casting machine, it is deoxidized by the addition of A to free the free molten steel in the mold constituting the continuous casting machine. [0
] to a stiffness of 7 or less. In this step, if the nozzle diameter of the ladle or tundish is small (15 side or less) as in a continuous billet casting machine, the nozzle is likely to be clogged by the A-deoxidized product A-203. Specifically, the free material in the port steel in the ladle and tundish obtained by deoxidizing by adding A
〔0〕が100肌以
下であるときはノズル詰りが多発する。従ってビレツト
を連続鋳造する場合にはタンデイッシュ迄の段階では自
由When [0] is less than 100 skins, nozzle clogging occurs frequently. Therefore, when continuously casting billets, the stage up to tundish is free.
〔0〕を100〜18伽皿‘こ調整してノズル詰りを
回避することとし、然る後、鋳型内漆鋼中の自由[0] was adjusted by 100 to 18 degrees to avoid nozzle clogging, and after that, the free space in the lacquered steel in the mold was
〔0〕
が7奴皿以下になるように、鋳型内溶鋼中にAそを添加
して脱酸を行う。なおタンディッシュ段階で自由[0]
Deoxidation is performed by adding A solute to the molten steel in the mold so that the amount of steel is 7 or less. In addition, it is free at the tundish stage.
〔0〕
を180脚以下とした理由はこの値を超えると鋳型内溶
鋼中へのAそ添加量が多くなりすぎて、自由[0]
The reason for setting 180 legs or less is that if this value is exceeded, the amount of A added to the molten steel in the mold becomes too large, and the free
〔0〕及び
Aク添加量の制御が困難になるためである。また自由〔
0〕が18功血を超えるとタンディツシュノズルの熔損
が激しくなって、溶損耐火物に起因する介在物の増加を
生じト場合によってはタンディツシュノズル部からの漏
鋼が起きる等、種々の不都合を招来する。Aそ添加方法
としては、Aそ粒を添加してもよいが、後述するように
タンディッシュ〜鋳型間を不活性ガスでシールした場合
に添加しやすく、且つ自由This is because it becomes difficult to control the amount of [0] and A added. Freedom again [
0] exceeds 18 degrees, the damage to the tundish nozzle becomes severe, resulting in an increase in inclusions caused by the eroded refractory, and in some cases, steel leakage from the tundish nozzle. cause inconvenience. As a method of adding A grains, A grains may be added, but as described later, it is easier and freer to add if the space between the tundish and the mold is sealed with an inert gas.
〔0〕の調整が行いやすいA
〆線供給法が好ましい。一方スラブ、ブルーム連続鋳造
機のように取鍋ノズル「タソディッシュノズルのノズル
蓬が15側め以上である場合は、このように脱酸処理を
2段階に分ける必要はなく、鋳造される迄のいずれかの
期間に自由[0] Easy to adjust A
The finishing line feeding method is preferred. On the other hand, when the ladle nozzle and the nozzle diameter of the tasso dish nozzle are 15 or more, as in a continuous slab/bloom casting machine, there is no need to separate the deoxidation treatment into two stages, and the free for any period
〔0〕を7功風以下にするのに必要最小限の
Aそ量を添加して脱酸処理を行えばよい。この添加場所
としては、前掲(4)の灘梓精錬中の転炉(榎合吹鍵炉
)内、あるし「は転炉から取鍋への出鋼中、出鋼後の取
鍋内もタンディッシュ内、更には鋳型内としてもよくも
また複数の場所で行ってもよい。Aと添加量は「添加前
の溶鋼中の自由Deoxidation treatment may be performed by adding the minimum amount of A necessary to reduce [0] to 7 or less. The place where this is added is inside the converter (Enoki Abuki Furnace) during the Nada Azusa refining mentioned in (4) above, or during tapping from the converter to the ladle, or inside the ladle after tapping. It may be done in the tundish, or even in the mold, or in multiple places.
〔0〕を例えば固体電池の如き電気化学
現象を利用した酸素プローブによって測定して決定する
がも談溶鋼は■の鷹伴精錬にて既に脱酸処理を受けてい
るため、極めて小量のAそ添加で港鋼中の自由[0] is determined by measuring it with an oxygen probe that utilizes an electrochemical phenomenon such as a solid-state battery, but since the steel has already been deoxidized at the Takatomo Refining process in (■), an extremely small amount of A is present. Freedom in Minato Steel with its addition
〔0〕を
7Q剛以下に迄脱酸でき「 A〆添加後の溶鋼中のT。
〔A〆〕はリムド鋼相当鋼として品質上要求される0。
020%以下に十分とどめることができる。
また転炉内又は取鍋内に公そを添加する場合には「 ス
ラグが実質的に存在しないのでスラグ中の自由[0] can be deoxidized to below 7Q stiffness.
[A〆] is 0, which is required for quality as a steel equivalent to rimmed steel.
It can be kept sufficiently below 0.020%. In addition, when adding soybean into the converter or ladle, there is no slag in the slag.
〔0〕に
よるAそのロスがない為「溶鋼中の自由A due to [0] Because there is no loss, "freedom in molten steel"
〔0〕を高精度
で制御できる。更にAそ添加時に溶鋼面上にスラグが存
在する場合は、Aそによってスラグ成分のSi02が一
部還元されて綾鋼中の〔Si〕が増加する所謂S;ピッ
クアップが起きるが、本発明においては同様にこの影響
も受けない。一方、耐火物中のSi02成分からのSi
ピックアップあるいはAそ地金に含まれているSiによ
って、溶鋼中の〔Si〕がわずかに増加することが考え
られるが「前述の如くT.〔Aそ〕ミ0.020%とす
る程度のAそ添加では〔SI〕の増加は極く徴量であり
「不可避的含有量に止まる。而して鋼材の用途に応じて
必要とされるMn等の合金元素の調整は「蝿洋精錬中の
転炉内又は転炉から取鍋への出鋼中若しくは出鋼後の敬
鍋内等に合金を添加することにより行う。
また転炉から取鍋への出鋼中に溶鋼が空気酸化されるの
を防止するため、出鋼時の溶鋼周辺はAr等の不活性ガ
スでシールするのが望ましい。更に取鍋に出鋼された溶
鋼は表面が空気に接しているので放熱防止「空気酸化防
止上の見地からフラックス又はもみがら等を投入するの
が好適である。なお〜上述した一連の工程では、通常の
連続鋳造前段階で要する工程よりも蝿梓精錬を行う時間
だけ処理時間が長くなるが「前述した如き真空処理を行
う場合に比して大幅に短か〈「溶鋼温度も通常の連続鋳
造の場合よりも特に高くする必要はない。次にこのよう
な脱酸処理を行った溶鋼は連続鋳造機にて鋳造されるが
t漆鋼中の自由[0] can be controlled with high precision. Furthermore, if slag is present on the surface of the molten steel when A slag is added, the slag component Si02 is partially reduced by the slag and the so-called S pick-up occurs, which increases the [Si] in the twill steel. is similarly unaffected by this. On the other hand, Si from the Si02 component in the refractory
It is conceivable that the amount of Si in the molten steel increases slightly due to Si contained in the pick-up or A so metal. With its addition, the increase in [SI] is extremely small and remains an unavoidable content.The adjustment of alloying elements such as Mn, which is required depending on the application of the steel material, This is done by adding an alloy to the inside of the converter, during tapping from the converter to the ladle, or into the ladle after tapping.Also, molten steel is air oxidized during tapping from the converter to the ladle. In order to prevent this, it is desirable to seal the area around the molten steel with an inert gas such as Ar during tapping.Furthermore, since the surface of the molten steel tapped into the ladle is in contact with air, it is necessary to prevent heat radiation and prevent air oxidation. From the above point of view, it is preferable to introduce flux or rice husks, etc.In addition, in the above-mentioned series of steps, the processing time will be longer by the time required to perform the fly azusa refining than the steps required in the stage before normal continuous casting. "The temperature of the molten steel does not need to be particularly higher than that of normal continuous casting. is cast using a continuous casting machine, but there is no freedom in the lacquered steel.
〔0〕は前述した7■肌以下の条件を満
足しているのでCO気泡は発生せず〜ピンホール等の欠
陥のない鍵片を安定的に製造することができる。なお連
続鋳造の際には溶鋼の再酸化を防止する処置もすなわち
敬鍋ゾズルとしてロングゾズルをt 夕ンデイツシュゾ
ズルとして浸債ノズルを使用し、且つ取鋼〜夕ンディッ
シュ間及び夕ンディッシュ〜鋳型間をAr等の不活性ガ
スでシールを行う等の公知の処置を採るのが望ましいQ
次に本発明の実施例を25仇肋厚のスラブ及び116肋
日のビレットを夫々製造する場合について詳述する。
第 1 表
tr;トレース
第 2 表
tr;トンース
まず25仇舷厚スラブを製造する場合は、第1表A欄(
処理前)記載の成分濃度及び温度をもつ綾銑27皿こ対
する脱流処理を予備的に行った。
これは熔銑の〔S〕は0.023%と一応〔S〕く0.
030%を満たしているが、特に低硫鋼を必要とした為
である。脱硫処理は溶銑鍋において、溶鉄中にソ−ダ灰
Na2C03を添加しィンベラの回転により溶鉄と混合
せしめるKR法(ソーダ灰Na2C03を懸濁させたガ
スを港銑中に吹込み添加混合せしめるィンジェクション
法でもよい)により行った。この脱硫処理後の各成分濃
度は第1表B欄(脱硫処理後)に示した如くになった。
その後脱硫処理にて生成したスラグを排除した後、この
溶銑を27倣転炉に装入し、生石灰(又はソーダ灰)を
添加して通常の酸素吹錬を行った。
その結果第1表C欄(転炉吹錬後)に記載したように、
〔P〕は所要の成分濃度、即ち0.030%以下になっ
た。また〔C〕は0.10%と0.05%よりも若干高
い値に止まった。次にこの纏常転炉吹鎌によって得た溶
鋼を取鍋に受鋼した後、リレードル法によりスラグカッ
トを行って「第1図に示す27山転炉(複合吹鎌炉)2
に装入した。
この転炉2にて造律剤を使用せずに純酸素上吹吹糠と蝿
洋精錬を併用してスラグレス榎合吹銭を行った。この複
合吹鏡には第1図に示した如き所謂後合吹鎌炉を用いる
が、底部に配した羽□1は内管内径12.7肋?、内外
管間隙1.1肋の2重管構造を有し、内管がCu、外管
がステンレス鋼で形成されていて「内管からは蝿梓用の
山を吹出させ、外管には羽□先端部を冷却するための炭
化水素ガスを遷流させた。酸素吹鉄の送酸速度は40,
00帆めノ時であり、蝿梓用〜の吹込速度は州でノ分で
ある。スラグレス複合吹錬によって第1表D欄(スラグ
レス吹銃後)に示した如く、〔C〕が0.07%、自由
Since [0] satisfies the above-mentioned condition of 7.0 cm or less, no CO bubbles are generated and key pieces without defects such as pinholes can be stably produced. During continuous casting, measures are taken to prevent re-oxidation of molten steel. ~It is desirable to take known measures such as sealing the space between the molds with an inert gas such as Ar.Q
Next, an embodiment of the present invention will be described in detail for producing a slab with a thickness of 25 mm and a billet with a thickness of 116 mm. 1st table tr; trace 2nd table tr; trace When manufacturing a 25 mm thick slab first, use Table 1 column A (
Preliminary deflow treatment was carried out on 27 plates of twill pig iron having the component concentrations and temperatures described in (Before treatment). This means that the [S] of the hot metal is 0.023%, which means that the [S] is 0.023%.
This is because low sulfur steel was particularly required. Desulfurization treatment is carried out using the KR method, in which soda ash Na2C03 is added to the molten iron in a hot metal ladle and mixed with the molten iron by the rotation of an in-vehicle (the KR method, in which a gas in which soda ash Na2C03 is suspended is blown into port pig iron and mixed). (The injection method may also be used.) The concentrations of each component after this desulfurization treatment were as shown in column B of Table 1 (after desulfurization treatment).
After removing the slag produced in the desulfurization treatment, the hot metal was charged into a 27-type converter, quicklime (or soda ash) was added, and ordinary oxygen blowing was performed. As a result, as stated in column C of Table 1 (after converter blowing),
[P] became the required component concentration, that is, 0.030% or less. Further, [C] remained at a value of 0.10%, slightly higher than 0.05%. Next, after receiving the molten steel obtained by using this continuous converter blowing sickle into a ladle, slag cutting was performed using the reidle method.
It was loaded into In this converter 2, slagless Enoki-Aibuki coins were made using pure oxygen Kamifuki bran and Enoki refining in combination without using a forging agent. This composite blowing mirror uses a so-called rear blowing sickle furnace as shown in Fig. 1, and the blade □1 placed at the bottom has an inner diameter of 12.7 ribs. It has a double tube structure with a gap of 1.1 ribs between the inner and outer tubes, and the inner tube is made of Cu and the outer tube is made of stainless steel. Hydrocarbon gas was transfused to cool the tip of the blade.The oxygen delivery rate of the oxygen blower was 40,
It was 0000 hours, and the blowing speed of the fly Azusa was about the same as in the state. As shown in column D of Table 1 (after slagless blowgun), [C] was 0.07% and free.
〔0〕が32■側となり、この〔C〕×[0] is on the 32■ side, and this [C]×
〔0〕は第2図
に示したように、Pco=1気圧のときの平衡状態より
も低い。次に酸素吹錬後、2個の羽□1の各内管から合
計2帆で/分の割合で〜を5分間熔鋼中に吹込み燈梓精
錬を行った。その結果、第1表E欄(蝿洋精錬後)に示
した如く、自由[0] is lower than the equilibrium state when Pco=1 atm, as shown in FIG. Next, after oxygen blowing, .about. was blown into the molten steel for 5 minutes at a rate of 2 sails/minute from each inner tube of two vanes □1 for 5 minutes to carry out tomato refining. As a result, as shown in column E of Table 1 (after fly refining), free
〔0〕が137鞘m‘こ迄脱醗された。
次いで複合吹錬炉から取鍋への出鋼時において、溶鋼中
の棒状のAそを43k9(溶鋼lt当り約0.16kg
)添加し、同時にMn成分調整のためHCFe−Mn(
Fe−Mn合金)を適量添加した。
またAそ脱酸によって生成するAそ203系介在物の浮
上を促進させるために、取鍋蓋をした後浸涜ランスを溶
鋼中に挿入しArによる蝿拝を行った。このAそ脱酸処
理後の各成分濃度を第1表F欄(Aク脱醗処理後)に示
すが、〔Si〕が0.009%、T。〔A夕〕が0.0
19%とIJムド鋼相当鋼種として十分な値を示してお
り、さらに自由[0] was removed to 137 pods.
Next, when tapping the steel from the composite blowing furnace to the ladle, the rod-shaped A-shaped steel in the molten steel is heated to 43k9 (approximately 0.16kg per lt of molten steel).
), and at the same time HCFe-Mn (
An appropriate amount of Fe-Mn alloy) was added. In addition, in order to promote the floating of A-203 type inclusions generated by A-so deoxidation, after the ladle was covered, a immersion lance was inserted into the molten steel and irradiation with Ar was performed. The concentrations of each component after the deoxidation treatment of A are shown in column F of Table 1 (after the deoxidation treatment of A). [Si] is 0.009%, T. [A evening] is 0.0
19%, which is a sufficient value as a steel type equivalent to IJ Mudo steel, and has even more freedom.
〔0〕は連続鋳造時に気泡を発生させる
おそれがない50柳を示した。次いで25仇肋厚のスラ
ブ連続鋳造機にて取鋼〜タンディツシュ間をArにてシ
ールしL取鋼メズルにロングノズルを、タンディツシュ
ノズルに浸簿ノズルを使用して引抜速度1.2仇/分で
鋳造したが、気泡の発生、従ってまたピンホールの発生
は皆無であり「表面性状の良好な鍵片が製造できた。次
にi16肌L]のピレツトを製造する場合について述べ
る。
第2表A欄(処理前)記載の成分濃度及び温度をもつ溶
鉄77tを溶鉄鍋にて〜 ソーダ灰を添加してKR法に
よる脱硫処理を行った。脱硫処理後の各成分濃度は第2
表B欄(脱硫処理後)に示した如くになった。その後脱
硫処理にて生成したスラグを排除した後t この溶銑を
7仇転炉に装入し、生石灰(又はソーダ灰)を添加して
通常の酸素吹鎌を行った。
その結果、第2表C欄(転炉吹鏡後)に記載したように
、〔P〕は所要の成分濃度になった。また〔C〕は0.
09%と0.05%より若干高い値に止まった。次にこ
の通常転炉吹鎌によって得た溶鋼を「取鍋に受鋼してス
ラグカットした後、通常の方法で次工程の第1図と同様
な構造の7批複合吹錬炉に装入し、ここで造樺剤を使用
せずに榎合吹銭を行った。
送酸速度は11,000Nで/時「蝿梓用Arの吹込速
度は刈れ/分である。なお羽□の材質は内管がCu、外
管がステンレス鋼と第亀図の場合と同じであるが、内管
内径は7.75脇?「内外管間隙は0.8他と形状は梢
々小さい。このスラグレス複合吹銭によって第2表D欄
(スラグレス吹鎌後)に示した如く、〔C〕が0.07
%し 自由[0] indicates 50 Yanagi, which has no risk of generating bubbles during continuous casting. Next, in a continuous slab casting machine with a thickness of 25 mm, the space between the tap steel and the tundish was sealed with Ar, and a long nozzle was used for the L-thread steel mezzle, and a dipping nozzle was used for the tundish nozzle, and the drawing speed was 1.2 m/s. Although it was cast in minutes, there were no air bubbles or pinholes, and a key piece with good surface quality was manufactured.Next, we will discuss the case of manufacturing a pilet with i16 skin L. 77 tons of molten iron having the component concentration and temperature listed in Table A column (before treatment) was desulfurized using the KR method with the addition of soda ash in a molten iron pot.The concentrations of each component after desulfurization were
The results were as shown in column B of Table (after desulfurization treatment). After removing the slag produced in the desulfurization treatment, the hot metal was charged into a 7-meter converter, quicklime (or soda ash) was added, and ordinary oxygen blowing was performed. As a result, as described in column C of Table 2 (after converter blowing), [P] reached the required component concentration. Also, [C] is 0.
The value remained slightly higher than 0.09% and 0.05%. Next, the molten steel obtained by this normal converter blowing sickle is received in a ladle, cut into slag, and then charged in the next process into a 7-piece composite blowing furnace with a structure similar to that shown in Figure 1. However, here, we carried out Enoki-bukisen without using a birch agent.The oxygen supply rate was 11,000N/hour. The inner tube is made of Cu and the outer tube is made of stainless steel, which is the same as in the case shown in Fig. 1, but the inner diameter of the inner tube is 7.75mm. As shown in column D of Table 2 (after slug-less blowing sickle), [C] is 0.07 due to composite blowing coins.
% freedom
〔0〕が341脚となり、これは第2図に示
したようにPc。=1気圧のときの平衡状態に近い。次
に酸素吹鏡後、2個の羽口の各内管から合計磯淋ノ分の
割合でArを5分間溶鋼中に吹込み縄梓精錬を行った。
その結果「第2表E欄(蝿洋精錬後)に示した如く、自
由[0] becomes 341 legs, which is Pc as shown in Figure 2. = Close to the equilibrium state when the pressure is 1 atm. Next, after oxygen blowing, Ar was blown into the molten steel for 5 minutes from each inner pipe of the two tuyeres at a total rate of Isohin to perform rope refining. As a result, as shown in column E of Table 2 (after fly refining), free
〔0〕は156脚に迄低下した。ビレットを製造する
場合は脱酸調整を一部連続鋳造機の鋳型内で行うので〜
タンディッシュ段階においては溶鋼中の自由[0] decreased to 156 legs. When producing billets, part of the deoxidation adjustment is done in the mold of the continuous casting machine.
At the tundish stage, there is no freedom in the molten steel.
〔0〕を
100〜18政磯こ調整しておくのであるが、この実施
例では網梓精錬によって溶鋼中の自由[0] is adjusted by 100 to 18 Masaiso, but in this example, the freeness in the molten steel is
〔0〕が156脚
とこの範囲に在るので、タンディッシュ段階迄はA〆添
加は行わずにHCFe−Mh投入によりMn成分の調整
のみを行った。
このようにして溶製された溶鋼を116地・−]のビレ
ット連続鋳造機にて鋳造する際に〜溶鋼lt当り200
夕の割合でAそ線を鋳型内溶鋼に供給した。
引抜速度は2.2のノ分でありもやはり溶鋼の再酸化を
防止するためにArにより「取鋼〜夕ンディッシュ間及
びタンディッシユ〜鋳型間のシールを行った6その結果
気泡の発生「従ってまたピンホールの発生は皆無であり
、表面性状の良好な銭片が製造できた。鋳型内溶鋼の各
成分濃度を第2表F欄(鋳型内熔鋼)に示したが、Si
脱酸は全く行っていないので、〔Si〕が0.010%
と低いことば当然であるが、T。〔Aそ〕も0.010
%と従来のA〆キルド鋼の0。030%以上に比して極
めて低くトリムド鋼相当鋼種として十分な値を示してい
る。
更に自由Since [0] was 156 legs and within this range, the Mn component was only adjusted by adding HCFe-Mh without adding A to the tundish stage. When the molten steel produced in this way is cast in a continuous billet casting machine with a capacity of 116 mm, ~ 200 lbs.
The A warp wire was supplied to the molten steel in the mold at a rate of 500 ml. Even though the drawing speed was 2.2 times, in order to prevent re-oxidation of the molten steel, sealing was performed between the drawing steel and the tundish and between the tundish and the mold.6 As a result, air bubbles were generated. In addition, there were no pinholes, and coins with good surface quality were manufactured.The concentrations of each component in the molten steel in the mold are shown in column F of Table 2 (molten steel in the mold).
Since no deoxidation was performed, [Si] was 0.010%.
Of course this is a low word, but T. [A so] is also 0.010
%, which is extremely low compared to 0.030% or more of conventional A-killed steel, and is a sufficient value as a steel equivalent to trimmed steel. Even more freedom
〔0〕も4数風と極めて低いので気泡の発生は
当然に起らなかった。上述の2つの実施例は〜いずれも
成品中のC量が0.03〜0.10%程度の低炭素リム
ド鋼相当品についてのものであるが、成品中のC量がO
JI〜0.25%程度の中「高炭素リムド鋼相当品につ
いても本発明が適用可能であることは言うまでもない。
けだし〔C〕が高い程酸素吹鎌終点自由[0] was also extremely low at just 4 winds, so naturally no bubbles were generated. The above two examples are both about products equivalent to low carbon rimmed steel with a C content of about 0.03 to 0.10%;
It goes without saying that the present invention is also applicable to products equivalent to high carbon rimmed steel with a JI of about 0.25%.
〔0〕は低くも
その後の脱酸処理が軽度であるからである。以上詳述し
た如く、本発明に係るスラグレス複合吹錬、瀦幹精錬を
中心とした一連の製鋼法は「Si脱酸を全く行わずにA
そ脱酸も極く軽度にとどめた溶鋼を連続鋳造可能ならし
め、ピンホール等の欠陥を有しないリムド鋼相当の鍵片
を高歩留り〜且つ高能率で得ることを可能としたもので
ありもまた真空処理を行わないので「設備が大掛りなも
のとはならす、また真空処理法にて脱酸を行う場合に比
して全工程所要時間が短かいため、溶鋼温度の低下が小
さく「操業上極めて有利である。このように本発明に係
る製鋼法は、従来の製鋼過程を大幅に変動させることな
く従来不可能とされていた低〔AZ〕、〔Si〕鋼L即
ちリムド鋼相当品の連続鋳造化を可能としたものであり
、まさにこの種技術に画期的な貢献をなすものといえる
。[0] is low, but the subsequent deoxidizing treatment is mild. As explained in detail above, a series of steel manufacturing methods centered on slagless composite blowing and slag refining according to the present invention are capable of producing A
It is possible to continuously cast molten steel with minimal deoxidation, and to obtain key pieces equivalent to rimmed steel without defects such as pinholes at a high yield and with high efficiency. In addition, since vacuum treatment is not performed, the equipment does not need to be large-scale, and the time required for the entire process is shorter than when deoxidizing using the vacuum treatment method, so the drop in molten steel temperature is small and operation is possible. As described above, the steel manufacturing method according to the present invention can produce low [AZ], [Si] steel L, that is, a product equivalent to rimmed steel, which was previously considered impossible, without significantly changing the conventional steel manufacturing process. This made continuous casting possible, and it can be said to be a revolutionary contribution to this type of technology.
第1図は後合吹鎌炉の模式的縦断面図、第2図はスラグ
レス複合吹鎌及び縄梓精錬の効果を示すグラフである。
亀・…・・羽口、2……転炉。菱‘図
菱2図FIG. 1 is a schematic longitudinal cross-sectional view of a rear-blow sickle furnace, and FIG. 2 is a graph showing the effects of the slag-less composite blow sickle and rope azusa refining. Turtle...tuyere, 2...converter. Diamond Diagram Diamond Diagram 2
Claims (1)
分濃度以下になすべく吹錬し、この吹錬した溶湯を溶湯
容器に出鋼した後、更に浴面下よりガスを導入し得るよ
うにした転炉に装入し、該転炉において酸素吹錬を行わ
ないか、あるいは造滓剤を実質的に添加することなく酸
素吹錬し、酸素吹錬を行う場合は該酸素吹錬中及び/又
は酸素吹錬後に、また酸素吹錬を行わない場合は転炉に
装入後に、鋼浴面下よりガスを導入して撹拌精錬を行い
、撹拌精錬中、撹拌精錬後における転炉から取鍋への出
鋼中、又は出鋼後の少くともいずれか一の期間において
Al添加による脱酸を行い、自由〔O〕が70ppm以
下、T.〔Al〕が0.020%以下、〔Si〕が不可
避的含有量である溶鋼を溶製し、該溶鋼を連続鋳造機に
より鋳造することを特徴とする製鋼法。 2 転炉において少くとも〔P〕を成品に要求される成
分濃度以下になすべく吹錬し、この吹錬した溶湯を溶湯
容器に出鋼した後、更に浴面下よりガスを導入し得るよ
うにした転炉に装入し、該転炉において酸素吹錬を行わ
ないか、あるいは造滓剤を実質的に添加することなく酸
素吹錬し、酸素吹錬を行う場合は該酸素吹錬中及び/又
は酸素吹錬後に、また酸素吹錬を行わない場合は転炉に
装入後に、鋼浴面下よりガスを導入して撹拌精錬を行い
、要すれば撹拌精錬中、撹拌精錬後における転炉から取
鍋への出鋼中、又は出鋼後の少くともいずれか一の期間
においてAl添加による脱酸を行い、自由〔O〕が10
0〜180ppm、〔Si〕が不可避的含有量である溶
鋼を溶製し、該溶鋼を連続鋳造機により鋳造するに際し
、該連続鋳造機を構成する鋳型内の溶鋼中にAlを添加
して脱酸処理を行い、鋳型内溶鋼の自由〔O〕を70p
pm以下、T.〔Al〕を0.020%以下、〔Si〕
を不可避的含有量とならしめることを特徴とする製鋼法
。[Scope of Claims] 1. Blowing is performed in a converter to reduce the concentration of [P] to at least the component concentration required for the finished product, and after the blown molten metal is poured into a molten metal container, it is further heated from below the bath surface. When oxygen blowing is carried out by charging the material into a converter into which gas can be introduced, and oxygen blowing is not performed in the converter, or oxygen blowing is performed without substantially adding a slag-forming agent. During the oxygen blowing and/or after the oxygen blowing, or if oxygen blowing is not performed, after charging into the converter, gas is introduced from below the surface of the steel bath to perform stirring refining. Deoxidation by adding Al is performed during tapping from the converter to the ladle after refining, or at least during one period after tapping, and free [O] is 70 ppm or less, T. A steel manufacturing method characterized by producing molten steel containing 0.020% or less of [Al] and an unavoidable content of [Si], and casting the molten steel using a continuous casting machine. 2 In the converter, blowing is performed to reduce the concentration of [P] to at least the component concentration required for the finished product, and after the blown molten metal is tapped into a molten metal container, gas is further introduced from below the bath surface. The material is charged into a converted converter, and oxygen blowing is not performed in the converter, or oxygen blowing is performed without substantially adding a slag-forming agent, and if oxygen blowing is performed, during the oxygen blowing. And/or after oxygen blowing, or if oxygen blowing is not performed, after charging into the converter, gas is introduced from below the surface of the steel bath to perform stirring refining, and if necessary, during stirring refining and after stirring refining. Deoxidation is performed by adding Al during or at least one period after tapping the steel from the converter to the ladle, and the free [O] is 10.
When melting molten steel with an unavoidable Si content of 0 to 180 ppm and casting the molten steel using a continuous casting machine, Al is added to the molten steel in the mold constituting the continuous casting machine to remove Al. Perform acid treatment to reduce the free [O] of molten steel in the mold to 70p
pm or less, T. [Al] 0.020% or less, [Si]
A steel manufacturing method characterized by making the content of
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP613180A JPS6010086B2 (en) | 1980-01-21 | 1980-01-21 | Steel manufacturing method |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP613180A JPS6010086B2 (en) | 1980-01-21 | 1980-01-21 | Steel manufacturing method |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS56102514A JPS56102514A (en) | 1981-08-17 |
JPS6010086B2 true JPS6010086B2 (en) | 1985-03-15 |
Family
ID=11629938
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP613180A Expired JPS6010086B2 (en) | 1980-01-21 | 1980-01-21 | Steel manufacturing method |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6010086B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0519503Y2 (en) * | 1986-08-29 | 1993-05-21 |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5763619A (en) * | 1980-10-06 | 1982-04-17 | Nippon Kokan Kk <Nkk> | Production of continuous cast steel |
JPS5834124A (en) * | 1981-08-25 | 1983-02-28 | Kawasaki Steel Corp | Controlling method for content of nitrogen in killed steel |
CN107012282B (en) * | 2016-01-27 | 2018-11-06 | 鞍钢股份有限公司 | Method for improving purity of high-quality ultra-low carbon steel |
-
1980
- 1980-01-21 JP JP613180A patent/JPS6010086B2/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0519503Y2 (en) * | 1986-08-29 | 1993-05-21 |
Also Published As
Publication number | Publication date |
---|---|
JPS56102514A (en) | 1981-08-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN102071287B (en) | Method for melting high-temperature-resistance and high-pressure-resistance alloy steel | |
CN106148844A (en) | A kind of preparation method of sulfur-bearing ultralow titanium high standard bearing steel | |
US3208117A (en) | Casting method | |
US3459537A (en) | Continuously cast steel slabs and method of making same | |
WO2022143363A1 (en) | Zr-containing welding wire steel hot-rolled wire rod and production process therefor | |
US4210442A (en) | Argon in the basic oxygen process to control slopping | |
US4247326A (en) | Free machining steel with bismuth | |
US9643241B2 (en) | Continuous casting method | |
JPS6010086B2 (en) | Steel manufacturing method | |
US3822735A (en) | Process for casting molten silicon-aluminum killed steel continuously | |
US3392009A (en) | Method of producing low carbon, non-aging, deep drawing steel | |
JP4207820B2 (en) | How to use vacuum degassing equipment | |
US9889499B2 (en) | Continuous casting method | |
EP3633051A1 (en) | Method for manufacturing high manganese steel ingot | |
US3990887A (en) | Cold working steel bar and wire rod produced by continuous casting | |
JPS5952921B2 (en) | Steel manufacturing method | |
JP2729458B2 (en) | Melting method of low nitrogen steel using electric furnace molten steel. | |
JPS5922766B2 (en) | Steel manufacturing method | |
JPS5952922B2 (en) | Steel manufacturing method | |
US3730704A (en) | Method for the production of killed,unalloyed or low-alloy,aluminum containing steel with low carbon content | |
CN113714683B (en) | Production method of steel wire rod for low-carbon high-strength welding wire | |
JPS6345901B2 (en) | ||
CN115821150B (en) | Control method for avoiding bubble defect of welding rod steel H08A | |
JPS6056051A (en) | Production of medium- and low-carbon ferromanganese | |
Bannenberg | Secondary metallurgy and continuous casting practice for clean steel production |