JPH0726140B2 - Converter steelmaking - Google Patents
Converter steelmakingInfo
- Publication number
- JPH0726140B2 JPH0726140B2 JP14312489A JP14312489A JPH0726140B2 JP H0726140 B2 JPH0726140 B2 JP H0726140B2 JP 14312489 A JP14312489 A JP 14312489A JP 14312489 A JP14312489 A JP 14312489A JP H0726140 B2 JPH0726140 B2 JP H0726140B2
- Authority
- JP
- Japan
- Prior art keywords
- blowing
- slag
- temperature
- blown
- measured
- 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 - Fee Related
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、上吹ランスから酸素を、底吹ノズルから撹拌
ガスを導入して吹錬を行なう転炉製鋼法に関する。Description: TECHNICAL FIELD The present invention relates to a converter steelmaking method in which oxygen is introduced from a top blowing lance and stirring gas is introduced from a bottom blowing nozzle to perform blowing.
転炉製鋼法、特に、P,S,Si量の低い予備処理銑を用いた
転炉精錬においては、鋼の清浄度や強度を左右するＰ
量、Mn量等の吹止値をより高い精度で制御して、所定特
性の鋼を安定して製造することが求められている。吹止
成分値を制御するためには、転炉内で吹錬に関与する材
料中の成分の総量すなわちトータルインプットを評価す
る必要がある。ここで、吹錬に関与する転炉内材料とし
ては、新らたに装入される主原料（溶銑、スクラップ、
型銑）と副原料（造滓材、冷却材、合金鉄）の他に、転
炉内に残留する前チャージスラグを考慮する必要があ
る。In the converter steelmaking method, especially in the converter smelting using pre-treated pig iron with a low P, S, Si content, the P
It is required to control the blow-off values such as Mn amount and Mn amount with higher accuracy to stably manufacture steel with predetermined characteristics. In order to control the blow-off component value, it is necessary to evaluate the total amount of components in the material involved in blowing in the converter, that is, the total input. Here, as the materials in the converter involved in the blowing, the main raw materials (hot metal, scrap,
It is necessary to consider the pre-charge slag remaining in the converter in addition to the mold pig iron and auxiliary raw materials (slagging material, coolant, ferroalloy).
特に、転炉内のスラグ量が減少した予備処理溶銑の転炉
吹錬では、前チャージスラグの影響が大きいが、従来
は、全チャージ残留スラグからのインプット分は定量化
が困難なため一定の値を設定していた。In particular, in the case of the pre-treatment hot metal converter blowing with reduced slag amount in the converter, the influence of the pre-charge slag is large, but in the past, it was difficult to quantify the input from the total residual charge slag The value was set.
たとえば、特にP,Mnの吹止値制御精度の向上を目的とし
た特開昭61−159520の方法では、吹錬開始前にスラグ中
蓄積酸素量Osの目標変化曲線を求めておき、転炉からの
排ガス情報を用いて実績Osを逐次算出し、これが目標変
化曲線に追従するように吹錬条件を制御する。この方法
は、スラグボリウムが大きい転炉操業では吹止〔Ｐ〕、
〔Mn〕制御への影響を低減させる効果があるが、前チャ
ージの残留スラグの寄与分は考慮されておらず、また転
炉の炉内情報として開接情報である排ガス情報を用いる
ため精度上限界がある。For example, in the method of Japanese Patent Application Laid-Open No. 61-159520, which is particularly aimed at improving the blow-off value control accuracy of P and Mn, a target change curve of the accumulated oxygen amount Os in the slag is obtained before the start of blowing, and the converter The actual Os is sequentially calculated by using the exhaust gas information from and the blowing conditions are controlled so that the actual Os follows the target change curve. This method is suitable for blowout stop [P] in converter operation with large slag volume.
Although it has the effect of reducing the influence on [Mn] control, the contribution of the residual slag of the previous charge is not taken into consideration, and since the exhaust gas information, which is the contact information, is used as the in-core information of the converter, the accuracy is improved. There is a limit.
また、マンガン鉱石を投入して溶鋼のマンガン濃度を調
整すると共に酸化カルシウム含有フラックスを投入して
スラグ塩基度を高める方法（特開昭61−204307）や、底
吹ノズルからの窒素吹込量と溶湯の窒素ピックアップ量
との関係を予め求めておき、窒素吹込時間の設定によっ
て終点窒素濃度を制御する方法（特開昭61−243111）が
知られているが、これらの方法でも前チャージ残留スラ
グの寄与分は考慮されていない。In addition, a method of adding manganese ore to adjust the manganese concentration of molten steel and adding a flux containing calcium oxide to increase the slag basicity (JP-A-61-204307), the amount of nitrogen blown from the bottom blowing nozzle and the molten metal There is known a method of controlling the end point nitrogen concentration by setting the nitrogen blowing time by previously determining the relationship with the nitrogen pickup amount of the above (Japanese Patent Laid-Open No. 61-243111). The contribution is not considered.
しかし、特にP,Mnについては、前チャージ残留スラグか
らのインプット分がかなり大きいため、単に一定の値を
設定したのではトータルインプットの評価精度が低いと
いう問題があった。However, especially for P and Mn, the input from the pre-charge residual slag is quite large, so there is a problem that the evaluation accuracy of the total input is low if a fixed value is set.
本発明は、従来困難とされていた残留スラグからのイン
プット分の定量化を行なうことによって、吹止成分値の
制御精度を高める転炉製鋼法を提供することを目的とす
る。It is an object of the present invention to provide a converter steelmaking method that enhances the accuracy of controlling the blow-off component value by quantifying the amount of input from the residual slag, which has been conventionally considered difficult.
上記の目的は、本発明にしたがえば、上吹ランスから酸
素を、下吹ノズルから撹拌ガスを吹き込んで吹錬を行う
転炉製鋼法において、 吹錬の開始前に、吹錬を施す溶銑の組成および温度、お
よび転炉内に残留する前チャージスラグの組成を実測
し、これら実測値を用いて全吹錬期間の酸素、撹拌ガ
ス、および副原料の導入パターンをあらかじめ初期設定
し、 上記初期設定パターンでの吹錬中に、溶融金属組成の安
定期間内のその金属組成および温度を実測し、その温度
におけるＰおよびMnの金属／スラグ分配式から、スラグ
中のＰおよびMn濃度を計算し、この計算値と溶銑のＰお
よびMn濃度の実測値と副原料から求めた発生スラグ量の
値を用いてＰおよびMnの物資収支に基づき転炉内の前チ
ャージ残留スラグ量を推定し、 これら実測値を用いてＰおよびMnのトータルインプット
量を求め、更に該トータルインプット量と吹止時のＰお
よびMnの金属／スラグ分配式から溶融金属の吹止組成お
よび吹止温度を推定し、これら推定値と対応する目標吹
止値との差に応じて酸素、撹拌ガス、および副原料の導
入パターンを修正し、 上記修正パターンでの吹錬中、吹錬終了の１〜５分前
に、溶融金属の炭素濃度および温度を実測し、これら実
測値を用いて溶融金属の吹止炭素濃度および吹止温度を
推定し、これら推定値と対応する目標吹止値との差に応
じて酸素、撹拌ガス、および副原料の導入パターンを再
修正することによって終点制御することを特徴とする転
炉製鋼法によって達成される。According to the present invention, the above-mentioned object is, in the converter steelmaking method in which oxygen is blown from the upper blowing lance and a stirring gas is blown from the lower blowing nozzle to blow the molten iron, before the start of the blowing The composition and temperature of, and the composition of the pre-charge slag remaining in the converter are actually measured, and the measured values are used to initialize the introduction patterns of oxygen, stirring gas, and auxiliary materials in advance for the entire blowing period, During blowing with the default pattern, the metal composition and temperature within the stable period of the molten metal composition were measured, and the P and Mn concentrations in the slag were calculated from the P / Mn metal / slag distribution equation at that temperature. Then, using this calculated value, the measured values of the P and Mn concentrations of the hot metal and the value of the generated slag amount obtained from the auxiliary material, the amount of pre-charge residual slag in the converter is estimated based on the material balance of P and Mn, Using these measured values Obtain the total input amount of P and Mn, and further estimate the blowout composition and blowout temperature of the molten metal from the total input amount and the P / Mn metal / slag distribution equation at the time of blowout, and correspond to these estimated values. The introduction pattern of oxygen, stirring gas, and auxiliary materials is modified according to the difference from the target blow-off value, and during the blowing with the above-mentioned modified pattern, the carbon concentration of the molten metal is 1-5 minutes before the end of blowing. And the temperature are measured, and the blown carbon concentration and blown temperature of the molten metal are estimated using these measured values, and oxygen, stirring gas, and auxiliary gas are added according to the difference between these estimated values and the corresponding target blown value. This is achieved by a converter steelmaking method characterized by end point control by re-correcting the feed pattern of raw materials.
本発明の方法においては、吹錬前に導入パターンを初期
設定する際に、従来行なわれていた溶銑成分・温度の実
測に加えて、前チャージ残留スラグ成分も実測し、更に
上記初期設定パターンでの吹錬中に溶融金属成分を実測
し、導入パターンを修正する。修正パターンでの吹錬中
に、従来のように溶融金属の炭素濃度および温度を実測
し、導入パターンを再修正し、吹止に至る。In the method of the present invention, when initializing the introduction pattern before blowing, in addition to the actual measurement of the hot metal component / temperature that has been conventionally performed, the pre-charge residual slag component is also measured, and further in the above-mentioned initial setting pattern. The molten metal composition is measured during the blowing of and the introduction pattern is corrected. During the blowing with the correction pattern, the carbon concentration and temperature of the molten metal are measured as in the conventional case, the introduction pattern is corrected again, and the blowing is stopped.
吹止成分値を制御するためのトータルインプットは式
（１）のように表わすことができる。式（１）はＰを被
制御成分とした場合についてのトータルインプット（To
tal P）として表わしたが、もちろんMn等の他成分につ
いても同様に表わすことができる。ここでは、式（１）
に沿ってＰを例として説明する。The total input for controlling the blow-off component value can be expressed by equation (1). Equation (1) is the total input (To
tal P), but of course other components such as Mn can be similarly expressed. Here, the formula (1)
Will be described by taking P as an example.
Total P＝〔Ｐ〕HM×WHM＋〔Ｐ〕SCR×WSCR ＋〔Ｐ〕CP×WCP＋〔Ｐ〕Ｆ×WF＋（Ｐ）Ｒ×SVR ＋（Ｐ）HM×SVHM …（１） である。このうち、従来は下線を付した項を実測し、他
の項は過去の吹錬実績データから適当な値を設定してい
た。Total P = [P] HM × W HM + [P] SCR × W SCR + [P] CP × W CP + [P] F × W F + (P) R × SV R + (P) HM × SV HM … (1) Is. Of these, conventionally, the underlined terms are actually measured, and the other terms are set to appropriate values from past blowing performance data.
本発明では、従来の実測項に加えて、上記実線枠で示し
た前チャージ残留スラグのＰ濃度（Ｐ）Ｒをも実測す
る。更に、上記破線枠で示した前チャージ残留スラグ量
SVを次に説明する方法で算出する。これら実測値（Ｐ）
Ｒと計算値SVRとから、Ｐのトータルインプットに大き
い影響を及ぼす前チャージ残留スラグの寄与分（Ｐ）Ｒ
×SVRを精度良く算出し、これによりＰのトータルイン
プットの評価精度を向上させ、吹止Ｐ値の制御精度を向
上させる。In the present invention, in addition to the conventional measurement item, the P concentration (P) R of the pre-charge residual slag shown by the solid line frame is also measured. Furthermore, the amount of residual slag before charge indicated by the broken line frame above
SV is calculated by the method described below. These measured values (P)
From R and calculated values SV R, the contribution of the large influence before the charge remaining slag total inputs P (P) R
× The SV R accurately calculated, thereby to improve the evaluation accuracy of P total input, to improve the control accuracy of吹止P values.
前チャージ残留スラグ量SVRは以下の方法で算出する。Before charging the residual amount of slag SV R is calculated by the following method.
式（２）で表わすように、吹錬開始前のTotal P（左
辺）と吹錬中のTotal P（右辺）との間にマスバランス
関係が成立する。As represented by equation (2), a mass balance relationship is established between Total P (left side) before starting blowing and Total P (right side) during blowing.
ここで、（Ｐ）R:前チャージ残留スラグのＰ濃度
（％）、SVR:前チャージ残留スラグ量（kg/ton）、ΣP:
溶銑・スクラップ・型銑・副原料・溶銑混入スラグ中の
Ｐの総量（kg/ton）（すなわち、式（１）右辺の前チャ
ージ残留スラグ項以外の項の和）、〔Ｐ〕1:吹錬中の溶
融金属のＰ濃度（％）、（Ｐ）1:吹錬中のスラグのＰ濃
度（％）、SV1:当チャージ発生スラグ量（kg/ton）、SV
HM:溶銑混入スラグ量（kg/ton） である。式（２）は溶融金属1ton（＝1000kg）当りにつ
いて表示した。添字の「１」は吹錬中のある特定時点
「１」における値であることを示す。 Here, (P) R : P concentration (%) of residual pre-charge residual slag, SV R : Pre-charge residual slag amount (kg / ton), ΣP:
Total amount of P (kg / ton) in the hot metal, scrap, hot metal, auxiliary material, hot metal mixed slag (that is, the sum of the terms other than the previous charge residual slag term on the right side of formula (1)), [P] 1 : blow P concentration (%) of molten metal during smelting, (P) 1 : P concentration of slag during blowing (%), SV 1 : Slag amount (kg / ton) of this charge generation, SV
HM : It is the amount of hot metal mixed slag (kg / ton). Formula (2) is shown for 1 ton (= 1000 kg) of molten metal. The subscript “1” indicates the value at a specific time “1” during blowing.
本発明においては、式（２）の各項のうち、前チャージ
残留スラグのＰ濃度（Ｐ）Ｒは前述のように吹錬開始前
に実測し、吹錬中の溶融金属のＰ濃度〔Ｐ〕１も実測す
る。In the present invention, in each term of the formula (2), the P concentration (P) R of the pre-charge residual slag is measured before the start of the blowing as described above, and the P concentration of the molten metal during the blowing [P ] 1 is also measured.
吹錬中のスラグのＰ濃度（Ｐ）１は、金属／メタル間の
Ｐ分配比LPから式（３）によって算出する。The P concentration (P) 1 of the slag during blowing is calculated from the metal / metal P distribution ratio L P by the formula (3).
すなわち、Ｐ分配比LPは、吹錬中のある測定時点「１」
における溶融金属の炭素濃度〔Ｃ〕１、温度T1等の関数
ｆとして、過去の吹錬実績データからマスバランス関係
によって得られる。この計算値LPと前記の実測値〔Ｐ〕
１から式（３）によって（Ｐ）１が算出される。 That, P distribution ratio L P is measured at some point during blowing "1"
As a function f of the carbon concentration [C] 1 of the molten metal, the temperature T 1 and the like in FIG. This calculated value L P and the above-mentioned measured value [P]
1 by the equation (3) (P) 1 is calculated from.
当チャージ発生スラグ量SV1は、副原料の装入量実績値
から式（４）によって算出する。This charge-generated slag amount SV 1 is calculated by the formula (4) from the actual value of the charging amount of the auxiliary raw material.
ここで、WF:副原料装入量（kg/ton）、ΣMn:装入原料中
の総Mn量（kg/ton）、〔Mn〕1:吹錬中の溶融金属のMn濃
度（％）、α：他の成分から発生するスラグ量（主とし
てSiO2）（kg/ton） である。これらのうち、WF,〔Mn〕１は実測値を用い
る。 Where W F : auxiliary raw material charging amount (kg / ton), ΣMn: total Mn amount in charging raw material (kg / ton), [Mn] 1 : Mn concentration (%) of molten metal during blowing , Α: Amount of slag (mainly SiO 2 ) (kg / ton) generated from other components. Of these, actually measured values are used for W F , [Mn] 1 .
また、式（４）中のΣMnおよびαはそれぞれ下記式
（５）および（６）によって算出する。Further, ΣMn and α in the equation (4) are calculated by the following equations (5) and (6), respectively.
ここで、加算される各項の意味は、 第１項＝溶銑からのインプット分、第２項＝スクラップ
からのインプット分、第３項＝型銑からのインプット
分、第４項＝Mn鉱石からのインプット分 であり、 〔Mn〕HM:溶銑Mn濃度（％） 〔Mn〕SCR:スクラップMn濃度（％） 〔Mn〕CP:型銑Mn濃度（％） WHM:溶銑量 WSCR:スクラップ量 WCP:型銑量 〔Mn〕Mn-Ore:Mn鉱石のMn濃度（％） WMn-Ore:Mn鉱石量 である。 Here, the meaning of each term to be added is: 1st term = input from hot metal, 2nd term = input from scrap, 3rd term = input from type pig, 4th term = from Mn ore [Mn] HM : Hot metal Mn concentration (%) [Mn] SCR : Scrap Mn concentration (%) [Mn] CP : Hot metal Mn concentration (%) W HM : Hot metal amount W SCR : Scrap amount W CP : type pig iron [Mn] M n -O re: Mn Mn concentration of ore (%) W M n -O re: Mn ore amount.
各加算項は、第１項〜第４項は式（５）と同じ意味であ
り、第５項は鉄鉱石からのインプット分であり、 〔Si〕HM:溶銑Si濃度（％） 〔Si〕SCR:スクラップSi濃度（％） 〔Si〕CP:型銑Si濃度（％） 〔Si〕Mn-Ore:Mn鉱石中Si濃度（％） 〔Si〕Fe-Ore:鉄鉱石Si濃度（％） である。 Each addition term has the same meaning as the first to fourth terms in the formula (5), and the fifth term is the input component from the iron ore. [Si] HM : Hot metal Si concentration (%) [Si] SCR: scrap Si concentration (%) [Si] CP: pig iron Si concentration (%) [Si] M n -O re: Mn ore Si concentration (%) [Si] F e -O re: iron ore Si concentration (%).
溶銑混入スラグ量SVHMは前記のように過去の吹錬実績デ
ータから適当に設定する。The amount of hot metal mixed slag SV HM is appropriately set from the past blowing performance data as described above.
上記のようにして、式（３）および（４）でそれぞれ計
算した（Ｐ）１およびSV1と、前記の実測値（Ｐ）R,
〔Ｐ〕１を式（２）に代入することにより前チャージ残
留スラグ量SVRを算出することができる。As described above, (P) 1 and SV 1 calculated by the equations (3) and (4), respectively, and the actual measured value (P) R ,
The [P] 1 can be calculated before the charge remaining amount of slag SV R by substituting the equation (2).
以上のようにして算出したSVRを式（２）の左辺に代入
することにより、Total Pを精度良く算出できる。The SV R calculated as described above by substituting the left side of the equation (2), the Total P can be accurately calculated.
本発明の方法を用いて吹止〔Ｐ〕値、吹止〔Mn〕値を制
御する場合の例を第１図のフローチャートを参照して説
明する。An example of controlling the blow-off [P] value and the blow-off [Mn] value using the method of the present invention will be described with reference to the flowchart of FIG.
転炉製鋼法において、吹錬開始前に酸素、撹拌ガス、副
原料の導入パターンを初期設定するためのスタティック
計算A1を行なう。この計算には、従来のように吹錬を施
す溶銑の成分・温度の実測値A2と目標吹止成分・温度の
設定値A4に加えて、前チャージ残留スラグ成分の実測値
A3（従来は設定値）をも用いる。得られた導入パターン
の指示A5に従って吹錬を開始する（Ｂ）。In the converter steelmaking method, static calculation A1 is performed before the start of blowing to initialize the introduction patterns of oxygen, stirring gas, and auxiliary materials. In this calculation, in addition to the measured value A2 of the component / temperature of the hot metal to be blown and the set value A4 of the target blowing stop component / temperature as in the past, the measured value of the pre-charge residual slag component was added.
A3 (previously set value) is also used. Blowing is started according to the instruction A5 of the obtained introduction pattern (B).
初期設定パターンでの吹錬中に、サブランスを用いて溶
融金属の成分および温度を実測し（C2）、この実測値を
用いてダイナミック計算−１（C1）を行なう。この計算
では、これら実測値から既に説明した方法で前チャージ
残留スラグの寄与分を精度良く算入したＰおよびMnのト
ータルインプットを求める。このP,Mnトータルインプッ
トと吹止時のP,Mnの金属／スラグ分配式から吹止P,Mn値
を精度良く推定する。この推定値と目標吹止値A4との差
に応じて、前記初期設定した酸素、撹拌ガス、副原料の
導入パターンを修正する。During the blowing with the initial setting pattern, the component and temperature of the molten metal are actually measured using the sublance (C2), and the dynamic calculation-1 (C1) is performed using the measured value. In this calculation, the total input of P and Mn in which the contribution of the pre-charge residual slag is accurately included is calculated from these measured values by the method already described. The P and Mn total input and the P / Mn metal / slag distribution formula at the time of blow stop can be used to accurately estimate the blow stop P and Mn values. According to the difference between this estimated value and the target blow-off value A4, the initially set introduction patterns of oxygen, stirring gas, and auxiliary material are corrected.
次に、上記修正パターンでの吹錬中、従来どおり吹錬終
了予定時点の１〜５分前にサブランスで溶融金属の炭素
濃度および温度を実測する（D2）。この実測値を用いて
ダイナミック計算−２（D1）を行ない溶融金属の吹止
〔Ｃ〕、吹止温度を推定し、これら推定値と目標吹止値
A4との差に応じて前記の導入パターンを再修正する。Next, during the blowing with the above-mentioned modified pattern, the carbon concentration and the temperature of the molten metal are actually measured by the sublance 1 to 5 minutes before the scheduled end of the blowing as usual (D2). Dynamic calculation-2 (D1) is performed using these measured values to estimate the blowout stop [C] and blowout temperature of the molten metal, and these estimated values and target blowout values
The introduction pattern is recorrected according to the difference from A4.
以後吹止Ｅまで、この再修正パターンで吹錬する。After that, blow until the blow stop E with this re-correction pattern.
吹止後、従来どおりサブランスを用いて、溶鋼の所要全
成分と温度を測定した（Ｆ）後出鋼（図示せず）する。After the blowing is stopped, all the required components and temperature of the molten steel are measured using a sublance as in the conventional case (F) Post-drawing steel (not shown).
初期設定パターンでの吹錬中に行なう溶融金属成分濃
度、温度の測定は、成分濃度の安定期間内に行なう。第
２図（ａ）および（ｂ）に、予備処理銑の従来吹錬過程
における溶融金属の（ａ）Ｐ濃度〔Ｐ〕および（ｂ）Mn
濃度〔Mn〕の推移を、溶融金属のＣ濃度〔Ｃ〕（すなわ
ち脱炭反応の進行）に対してそれぞれ示す。Ｃ濃度
〔Ｃ〕は、図の右端の溶銑〔Ｃ〕値から、吹錬による脱
炭の進行に従って、図の左端の吹止〔Ｃ〕値まで低下す
る。全吹錬期間の30〜90％経過領域に、〔Ｐ〕，〔Mn〕
が実質的に変化しない濃度安定期間が存在する。本発明
においては、この濃度の安定期間内に上記測定を行な
う。The measurement of the concentration and temperature of the molten metal component, which is performed during the blowing with the initial setting pattern, is performed within the stable period of the component concentration. 2 (a) and 2 (b), (a) P concentration [P] and (b) Mn of molten metal in the conventional blowing process of the pretreated pig iron.
The transition of the concentration [Mn] is shown with respect to the C concentration [C] of the molten metal (that is, the progress of the decarburization reaction). The C concentration [C] decreases from the hot metal [C] value at the right end of the figure to the blow stop [C] value at the left end of the figure as the decarburization by blowing proceeds. 30 to 90% of the total blowing period, [P], [Mn]
There is a concentration stable period during which the concentration does not substantially change. In the present invention, the above measurement is performed within the stable period of this concentration.
本発明の方法によって、予備処理銑を転炉にて吹錬し
た。The pre-treated pig iron was blown in a converter according to the method of the present invention.
用いた転炉は、300ton上底吹転炉であった。吹錬の対象
とした予備処理銑は、トーピードカーにてスケール、生
石灰を主成分とする脱リン剤をN2ガスで吹込むことによ
って脱リン、脱硫処理を行なったものである。この予備
処理銑の温度は1230℃〜1300℃であり、組成範囲は、第
１表のとおりであった。The converter used was a 300 ton top and bottom blowing converter. The pre-treated pig iron subjected to the blowing was subjected to dephosphorization and desulfurization treatment by blowing a dephosphorizing agent containing scale and quick lime as a main component with N 2 gas in a torpedo car. The temperature of this pretreated pig iron was 1230 ° C to 1300 ° C, and the composition range was as shown in Table 1.
本発明の方法にしたがって17チャージの吹錬を行なっ
た。 Blowing 17 charges was performed according to the method of the present invention.
各チャージについて吹錬開始前に、それぞれ前チャージ
の残留スラグ組成を実測した。この実測値を用いて、第
１図を参照して説明したようにスタティック計算を実施
し、酸素、撹拌ガス、副原料の導入量を初期設定した。The residual slag composition of each charge was measured before the start of blowing for each charge. Using these measured values, static calculation was performed as described with reference to FIG. 1, and the amounts of oxygen, stirring gas, and auxiliary materials introduced were initialized.
この初期設定パターンに沿って吹錬を行ない、各チャー
ジの全吹錬期間の30〜80％の時期に溶融金属の組成およ
び温度についてサブランス測定（第１図C2）を行った。
この測定による実測値を用いて、第１図C1で説明したよ
うにダイナミック計算を行ない。前チャージスラグ混入
量から吹止時の〔Ｐ〕，〔Mn〕，〔Ｃ〕、および温度を
推定し、追加副原料投入量を算出して、上記初期設定導
入パターンを修正した。Blowing was performed according to this initial setting pattern, and sublance measurement (C2 in FIG. 1) was performed on the composition and temperature of the molten metal at a time of 30 to 80% of the total blowing period of each charge.
Using the actual measurement value obtained by this measurement, dynamic calculation is performed as described in FIG. 1C1. The [P], [Mn], [C], and the temperature at the time of blow stop were estimated from the amount of the precharge slag mixed, the amount of the additional auxiliary material input was calculated, and the initial setting introduction pattern was corrected.
以後、上記修正導入パターンで吹錬を行ない、従来のよ
うに吹錬完了１〜３分前に溶融金属の炭素濃度および温
度についてサブランス測定（第１図D2）を行なった。こ
の実測値を用いてダイナミック計算（第１図D1）を行な
い、吹止〔Ｐ〕および温度を推定し、追加副原料投入量
を算出して上記修正導入パターンを再修正した。Thereafter, blowing was carried out in the above-mentioned modified introduction pattern, and sublance measurement (D2 in FIG. 1) was performed for the carbon concentration and temperature of the molten metal one to three minutes before the completion of blowing as in the conventional case. Using this measured value, dynamic calculation (D1 in FIG. 1) was performed to estimate the blow-off [P] and temperature, calculate the additional auxiliary raw material input amount, and re-correct the above-mentioned modified introduction pattern.
以後、この再修正導入パターンで吹止まで吹錬を行なっ
た。After that, this re-correction introduction pattern was used to blow until the blow was stopped.
吹止後、吹止成分測定のためのサブランス測定（第１図
Ｆ）を行なった。After the blowing was stopped, a sublance measurement (FIG. 1F) for measuring the blowing component was performed.
比較例 比較のため、上記実施例の工程のうち、前チャージスラ
グ組成の測定（第１図A3）および１回目のサブランス測
定（同C2）とこれによるダイナミック計算（同C1）の工
程を行なわず、その他は実施例と同様に行なう従来の方
法で、実施例と同様の温度・組成の予備処理銑の吹錬を
17チャージ行なった。Comparative Example For comparison, of the steps of the above-mentioned example, the steps of the previous charge slag composition measurement (A3 in FIG. 1) and the first sublance measurement (the same C2) and the dynamic calculation (the same C1) were not performed. Other than that, the conventional method is carried out in the same manner as in the example, and the blowing of the pretreated pig iron having the same temperature and composition as the example is performed.
I made 17 charges.
同一組成の溶銑についての吹錬結果の典型的な例を第２
表および第３表に示す。Second typical example of blowing results for hot metal of the same composition
The results are shown in Table 3 and Table 3.
また、実施例および比較例の全チャージの吹止〔Ｐ〕，
吹止〔Mn〕の推定値と実測値の対応を、〔Ｐ〕について
は第３図および第４図に、〔Mn〕については第５図およ
び第６図に示す。各図中に、実測値と推定値の相関性を
σ値で示す。 In addition, blowing stop of all charges in the examples and comparative examples [P],
Correspondence between the estimated value and the measured value of the blow stop [Mn] is shown in FIGS. 3 and 4 for [P] and in FIGS. 5 and 6 for [Mn]. In each figure, the correlation between the actually measured value and the estimated value is shown by σ value.
これらの結果から、本発明の方法は従来法にくらべて、
偏差が約1/2に減少しており、著しく高い精度で吹止成
分を制御できることがわかる。From these results, the method of the present invention is
The deviation is reduced to about 1/2, and it can be seen that the blow-off component can be controlled with extremely high accuracy.
以上説明したように、本発明の転炉製鋼法は、各成分の
トータルインプットにおける前チャージ残留スラグの寄
与分を精度よく求め、これに基ずいて酸素、撹拌ガス、
副原料の導入パターンを吹錬中に修正することができる
ので、従来よりも著しく高い精度で吹止成分値を制御す
ることができる。As described above, the converter steelmaking method of the present invention accurately determines the contribution of the precharge residual slag in the total input of each component, based on this, oxygen, stirring gas,
Since the introduction pattern of the auxiliary raw material can be corrected during the blowing, the blowing stop component value can be controlled with significantly higher accuracy than before.
第１図は、本発明にしたがった転炉製鋼法における操作
手順を示す工程図、 第２図（ａ）および（ｂ）は、吹錬の進行に伴う脱炭の
経過と溶融金属のＰ量およびMn量の推移をそれぞれ示す
グラフ、 第３図は、本発明にしたがった転炉製鋼法による吹止Ｐ
濃度の計算値と実測値の相関を示すグラフ、 第４図は、従来の転炉製鋼法による吹止Ｐ濃度の計算値
と実測値の相関を示すグラフ、 第５図は、本発明にしたがった転炉製鋼法による吹止Mn
濃度の計算値と実測値の相関を示すグラフ、および 第６図は、従来の転炉製鋼法による吹止Mn濃度の計算値
と実測値の相関を示すグラフである。FIG. 1 is a process diagram showing an operating procedure in a converter steelmaking method according to the present invention, and FIGS. 2 (a) and 2 (b) are decarburization progress and P amount of molten metal with progress of blowing. And a graph showing transitions of Mn amount, respectively, and FIG. 3 is a blow stop P by the converter steelmaking method according to the present invention.
FIG. 4 is a graph showing the correlation between the calculated value and the measured value of the concentration, FIG. 4 is a graph showing the correlation between the calculated value and the measured value of the blowout P concentration by the conventional converter steelmaking method, and FIG. 5 is in accordance with the present invention. Blown Mn by the converter steelmaking method
FIG. 6 is a graph showing the correlation between the calculated value and the measured value of the concentration, and FIG. 6 is a graph showing the correlation between the calculated value and the measured value of the blowout Mn concentration by the conventional converter steelmaking method.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中野 晃 千葉県君津市君津１番地 新日本製鐡株式 会社君津製鐡所内 (56)参考文献 特開 昭57−131309（ＪＰ，Ａ) 特開 昭57−131310（ＪＰ，Ａ) 特開 昭63−18015（ＪＰ，Ａ) 特開 昭59−136652（ＪＰ，Ａ) 特公 昭59−1767（ＪＰ，Ｂ２) 特公 昭58−58405（ＪＰ，Ｂ２) 特公 昭62−48723（ＪＰ，Ｂ２) ─────────────────────────────────────────────────── ─── Continuation of front page (72) Akira Nakano 1 Kimitsu, Kimitsu-shi, Chiba Shin-Nippon Steel Manufacturing Co., Ltd. Kimitsu Steel Corporation (56) Reference JP-A-57-131309 (JP, A) JP-A-SHO 57-131310 (JP, A) JP 63-18015 (JP, A) JP 59-136652 (JP, A) JP 59-1767 (JP, B2) JP 58-58405 (JP, B2) Japanese Patent Sho 62-48723 (JP, B2)
Claims (1)
拌ガスを吹き込んで吹錬を行う転炉製鋼法において、 吹錬の開始前に、吹錬を施す溶銑の組成および温度、お
よび転炉内に残留する前チャージスラグの組成を実測
し、これら実測値を用いて全吹錬期間の酸素、撹拌ガ
ス、および副原料の導入パターンをあらかじめ初期設定
し、 上記初期設定パターンでの吹錬中に、溶融金属組成の安
定期間内のその金属組成および温度を実測し、その温度
におけるＰおよびMnの金属／スラグ分配式から、スラグ
中のＰおよびMn濃度を計算し、この計算値と溶銑のＰお
よびMn濃度の実測値と副原料から求めた発生スラグ量の
値を用いてＰおよびMnの物資収支に基づき転炉内の前チ
ャージ残留スラグ量を推定し、 これら実測値を用いてＰおよびMnのトータルインプット
量を求め、更に該トータルインプット量と吹止時のＰお
よびMnの金属／スラグ分配式から溶融金属の吹止組成お
よび吹止温度を推定し、これら推定値と対応する目標吹
止値との差に応じて酸素、撹拌ガス、および副原料の導
入パターンを修正し、 上記修正パターンでの吹錬中、吹錬終了の１〜５分前
に、溶融金属の炭素濃度および温度を実測し、これら実
測値を用いて溶融金属の吹止炭素濃度および吹止温度を
推定し、これら推定値と対応する目標吹止値との差に応
じて酸素、撹拌ガス、および副原料の導入パターンを再
修正することによって終点制御することを特徴とする転
炉製鋼法。1. In a converter steelmaking method in which oxygen is blown from an upper blowing lance and a stirring gas is blown from a lower blowing nozzle to perform blowing, before the start of blowing, the composition and temperature of hot metal to be blown, and The composition of the pre-charge slag remaining in the furnace is measured, and the measured values are used to initialize the introduction patterns of oxygen, stirring gas, and auxiliary raw materials in advance during the entire blowing period. Inside, the metal composition and temperature within the stable period of the molten metal composition were actually measured, and the P and Mn concentrations in the slag were calculated from the P / Mn metal / slag distribution equation at that temperature, and the calculated value and the hot metal Pre-charge residual slag amount in the converter is estimated based on the material balance of P and Mn by using the measured values of P and Mn concentrations of P and Mn and the value of the generated slag amount obtained from the auxiliary raw material. And Mn total Input amount, and estimate the blowout composition and blowout temperature of the molten metal from the total input amount and the metal / slag distribution formula of P and Mn at the time of blowout. The introduction pattern of oxygen, stirring gas, and auxiliary raw material is corrected according to the difference of the above, and the carbon concentration and temperature of the molten metal are measured during the blowing with the above-mentioned corrected pattern and 1 to 5 minutes before the end of the blowing Estimate the blown carbon concentration and blown temperature of the molten metal using these measured values, and determine the introduction pattern of oxygen, stirring gas, and auxiliary materials according to the difference between these estimated values and the corresponding target blown value. A converter steelmaking method characterized in that the end point is controlled by recorrecting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14312489A JPH0726140B2 (en) | 1989-06-07 | 1989-06-07 | Converter steelmaking |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14312489A JPH0726140B2 (en) | 1989-06-07 | 1989-06-07 | Converter steelmaking |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0310012A JPH0310012A (en) | 1991-01-17 |
| JPH0726140B2 true JPH0726140B2 (en) | 1995-03-22 |
Family
ID=15331475
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14312489A Expired - Fee Related JPH0726140B2 (en) | 1989-06-07 | 1989-06-07 | Converter steelmaking |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0726140B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5567222A (en) * | 1994-03-24 | 1996-10-22 | Kawasaki Steel Corporation | Method of controlling slag coating of a steel converter |
| JP6798554B2 (en) * | 2016-07-27 | 2020-12-09 | 日本製鉄株式会社 | Method of manufacturing molten steel |
| CN115715331A (en) * | 2020-07-01 | 2023-02-24 | 杰富意钢铁株式会社 | Converter blowing control method and converter blowing control system |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57131309A (en) * | 1981-02-03 | 1982-08-14 | Sumitomo Metal Ind Ltd | Method for controlling content of manganese of molten steel |
| JPS57131310A (en) * | 1981-02-06 | 1982-08-14 | Sumitomo Metal Ind Ltd | Method for controlling content of phosphorus of molten steel |
| JPS5858405A (en) * | 1981-09-30 | 1983-04-07 | Matsushita Electric Ind Co Ltd | Measuring device for plate body |
| JPS591767A (en) * | 1982-06-25 | 1984-01-07 | クロイ電機株式会社 | Detection of fabric splice |
| JPS6248723A (en) * | 1985-08-27 | 1987-03-03 | Showa Denko Kk | Production of oxidized polymer |
| JPS6318015A (en) * | 1986-07-09 | 1988-01-25 | Nippon Kokan Kk <Nkk> | Method for estimating concentration of manganese in converter blowing |
-
1989
- 1989-06-07 JP JP14312489A patent/JPH0726140B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0310012A (en) | 1991-01-17 |
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