JPH04105756A - Method for controlling drift of molten steel in continuous casting mold - Google Patents
Method for controlling drift of molten steel in continuous casting moldInfo
- Publication number
- JPH04105756A JPH04105756A JP21909690A JP21909690A JPH04105756A JP H04105756 A JPH04105756 A JP H04105756A JP 21909690 A JP21909690 A JP 21909690A JP 21909690 A JP21909690 A JP 21909690A JP H04105756 A JPH04105756 A JP H04105756A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- mold
- drift
- continuous casting
- flow
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 58
- 239000010959 steel Substances 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 title claims abstract description 22
- 238000009749 continuous casting Methods 0.000 title claims abstract description 15
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims abstract description 42
- 229910052786 argon Inorganic materials 0.000 claims abstract description 21
- 230000004907 flux Effects 0.000 claims abstract description 12
- 238000007664 blowing Methods 0.000 claims abstract description 5
- 239000007789 gas Substances 0.000 claims description 42
- 230000000452 restraining effect Effects 0.000 abstract 1
- 239000011261 inert gas Substances 0.000 description 19
- 238000007654 immersion Methods 0.000 description 18
- 239000011449 brick Substances 0.000 description 7
- 238000005266 casting Methods 0.000 description 6
- 238000009529 body temperature measurement Methods 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 102220632799 Immunoglobulin heavy variable 1-69_R11A_mutation Human genes 0.000 description 1
- 102100025490 Slit homolog 1 protein Human genes 0.000 description 1
- 101710123186 Slit homolog 1 protein Proteins 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Continuous Casting (AREA)
Abstract
Description
【発明の詳細な説明】
〈産業上の利用分野〉
本発明は、連続鋳造鋳型内における溶鋼の偏流制御方法
に関する。DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for controlling the drift of molten steel in a continuous casting mold.
〈従来の技術〉
一般に、連続鋳造における溶鋼中の非金属介在物は、溶
鋼の注入流によって鋳片内部にまで持ち込まれる。その
大部分は湯面上に浮上するが、残る一部は鋳片内にその
まま捕捉され、丸鋳片品質の劣化を招く。この捕捉され
る非金属介在物の量は。<Prior Art> Generally, non-metallic inclusions in molten steel in continuous casting are carried into the inside of a slab by the injection flow of molten steel. Most of it floats to the surface, but the remaining part is trapped inside the slab, causing deterioration in the quality of the slab. The amount of non-metallic inclusions captured is:
鋳込み時の鋳片内溶鋼流によって大きく変化することが
知られており、浸漬ノズルから吐出される溶鋼流速が速
く、かつ溶鋼流が鋳型内深くにまで達すれば達する程、
増加する傾向にある。It is known that the flow rate of molten steel in the slab during casting changes greatly, and the faster the flow rate of molten steel discharged from the immersion nozzle and the deeper the molten steel flow reaches inside the mold, the more
There is a tendency to increase.
したがって、連続鋳造においては、浸漬ノズルから吐出
される溶鋼流が鋳型内深くまで達しないように、浸漬ノ
ズルは側方に吐出孔を有する形状とされ、しかも、鋳型
内温鋼表面に浮遊する表面被覆用フラックスを巻き込ま
ぬように、吐出孔は若干下向きとされて使用されている
。Therefore, in continuous casting, the immersion nozzle is shaped with a discharge hole on the side so that the molten steel flow discharged from the immersion nozzle does not reach deep into the mold, and the surface of the molten steel that floats on the surface of the heated steel inside the mold. The discharge hole is oriented slightly downward to avoid entraining the coating flux.
第１２図はその説明図である。スラブ連鋳機においては
、鋳型１の中央に浸漬ノズル２が配置され、その吐出孔
３ａ、３ｂは鋳型１の両短辺側に向けられ、吐出孔３ａ
、３ｂから吐出される溶鋼流は、鋳型１内を矢示４．５
のように流動する。すなわち、吐出孔３からの溶鋼流は
、鋳型１内に滞留される溶鋼６の中を流れる間にその速
度を減少し、鋳型１の各短辺側面への衝突によって反転
流となり、この反転流は、一方は場面側に向かう上昇流
４Ａ、５Ａ、他方は下方に向かう下降流４Ｂ、５Ｂとな
り、この間に大きく減速される結果、上昇流４Ａ、５Ａ
は場面上のフラックス７を渦中に巻き込むことなく、ま
た下降流４Ｂ、５Ｂは鋳片内深くにまで達しないように
して、鋳片品質を高める鋳造が実施されている。FIG. 12 is an explanatory diagram thereof. In the continuous slab casting machine, a submerged nozzle 2 is arranged in the center of a mold 1, and its discharge holes 3a and 3b are directed toward both short sides of the mold 1, and the discharge holes 3a and 3b are directed toward both short sides of the mold 1.
The molten steel flow discharged from , 3b moves inside the mold 1 as indicated by the arrow 4.5.
Flowing like. That is, the molten steel flow from the discharge hole 3 reduces its speed while flowing through the molten steel 6 retained in the mold 1, and becomes a reverse flow by colliding with each short side of the mold 1, and this reverse flow , one is an upward flow 4A, 5A heading towards the scene side, and the other is a downward flow 4B, 5B heading downward, and as a result of being greatly decelerated during this time, the upward flow 4A, 5A
Casting is carried out to improve the quality of the slab by preventing the flux 7 on the surface from being drawn into the vortex, and by preventing the downward flows 4B and 5B from reaching deep into the slab.
しかし、第１２回の関係は、両畦出孔３ａ、３ｂからの
溶鋼流が均等である場合に生しるものであり、浸漬ノズ
ル２に取付けられているスライディングノズル（図示せ
ず）の絞り開度や鋳込速度などにより、浸漬ノズル２を
下降する溶鋼流動にゆらぎが生じた場合、あるいは、浸
漬ノズル２の内壁にアルミナ等の非金属介在物が付着し
た場合、左右の吐出孔３ａ、３ｂの均等関係は崩れ、い
ずれか一方からの溶鋼流動が強くなり、いわゆる偏流が
生しることとなる。However, the twelfth relationship occurs when the molten steel flows from both ridge holes 3a and 3b are uniform, and the molten steel flow from both the ridge nozzles 3a and 3b is equal. If fluctuations occur in the flow of molten steel descending through the immersion nozzle 2 due to the opening degree or casting speed, or if non-metallic inclusions such as alumina adhere to the inner wall of the immersion nozzle 2, the left and right discharge holes 3a, The equality relationship 3b collapses, and the flow of molten steel from either side becomes stronger, resulting in so-called drifting.
そのような偏流が発生すると、鋳型内温ｆｉｌ流のうち
、強い流動を生した側は、上昇流あるいは下降流が強く
なる結果、フラックス巻き込みあるいは鋳片内部深くま
で下降流が達することに起因した内部欠陥を生し、品質
劣化の原因となる。When such a drift occurs, the side of the mold internal temperature film flow that has a strong flow will have a strong upward or downward flow, resulting in flux entrainment or a downward flow reaching deep inside the slab. This may cause internal defects and cause quality deterioration.
従来、上記した溶鋼の偏流を検出する手段としては、例
えば特開昭６２−２５２６５０号公報に開示されている
ように、左右の鋳型短辺の壁面に複数の熱電対を上下方
向に所定の間隔で埋設し、その温度情報から左右の湯面
レベル差を検出し、そのレベル差を電磁撹拌装置（ＥＭ
Ｓ）により解消する方法や、特開昭６２−２５２６４９
号公報に開示されているように、浸漬ノズル内に吹き込
むガス量を左右独立に制御することによって、左右レベ
ル差を解消する方法などが提案されている。Conventionally, as a means for detecting the above-mentioned drifting of molten steel, as disclosed in Japanese Patent Application Laid-Open No. 62-252650, a plurality of thermocouples are placed on the walls of the short sides of the left and right molds at predetermined intervals in the vertical direction. The temperature information is used to detect the difference in the level of the left and right water levels, and the difference in level is measured using an electromagnetic stirring device (EM).
S) and Japanese Patent Application Laid-Open No. 62-252649.
As disclosed in the above publication, a method has been proposed in which the left and right level differences are eliminated by independently controlling the amount of gas blown into the immersion nozzle.
〈発明が解決しようとするｇＪＩ！ｓ＞しかしながら、
特開昭６２−２５２６５０号公報の電磁攪拌装置（ＥＭ
Ｓ）を利用する方法では、偏流の程度とそれを解消する
ための攪拌力の関係が明記されておらず、もし、一定の
攪拌力が使用されているのであれば、溶鋼流動の時間的
変化（グイナミクス）を考慮したものにはなっておらず
、制御精度に問題がある。また、上述の公報において利
用されている偏流検知方法に関してであるが、本願発明
者らも同様の鋳型銅板測温実験を行い、特型内左右の溶
鋼レベル差を最もよく表現できる、銅板測温データに基
づく指標を探った結果、本出願人が先に出願した特願昭
６２−９３０５４号に示された方法よりも、鋳型長辺幅
方向温度分布に基づく方が、溶鋼レベル差の推定精度が
高いことがわかった。<gJI that invention tries to solve! s＞However,
The electromagnetic stirring device (EM
In the method using S), the relationship between the degree of drift and the stirring force used to eliminate it is not specified, and if a constant stirring force is used, the temporal change in molten steel flow would be (Guynamics) is not taken into account, and there are problems with control accuracy. Regarding the drift detection method used in the above-mentioned publication, the present inventors also conducted a similar mold copper plate temperature measurement experiment, and found that the copper plate temperature measurement method that can best express the difference in the level of molten steel on the left and right sides of the special mold. As a result of searching for indicators based on data, it was found that the method based on the temperature distribution in the long side width direction of the mold is more accurate in estimating the difference in molten steel level than the method shown in Japanese Patent Application No. 62-93054, which the present applicant previously filed. was found to be high.
本発明は、上記のような従来技術が有する課題を解決す
べくしてなされたものであって、連続鋳造鋳型内におい
て高精度で溶鋼の偏流を検知し、偏流の程度に応じて、
浸漬ノズル上部位置のアルゴンガス流量を両短片側で個
別流量制御することにより、溶鋼偏流を抑える方法を提
供することを目的とするものである。The present invention was made in order to solve the problems of the prior art as described above, and it detects drifting of molten steel with high accuracy in a continuous casting mold, and detects drifting of molten steel in accordance with the degree of drifting.
The purpose of this invention is to provide a method for suppressing drifting of molten steel by individually controlling the flow rate of argon gas at the upper part of the immersion nozzle on both short sides.
〈課題を解決するための手段〉
上記目的を達成するための本発明は、連続鋳造鋳型内の
長辺幅方向の温度分布を検出して、該温度分布または熱
流束分布の鋳型の中央部に対する右半分のパターンと左
半分のパターンを比較することにより、溶鋼偏流の発生
の有無を検知し、その発生方向および程度に応して、浸
漬ノズルの吐出孔上部位置のアルゴンガス吹込み流量を
両短辺側で個別流量制御することにより、鋳型的溶鋼偏
流を制御することを特徴とする連続鋳造鋳型内における
溶鋼の偏流！！ＪＩ１１方法である。<Means for Solving the Problems> To achieve the above object, the present invention detects the temperature distribution in the long side width direction within the continuous casting mold, and determines the temperature distribution or heat flux distribution with respect to the central part of the mold. By comparing the pattern on the right half and the pattern on the left half, it is possible to detect whether or not a molten steel drift occurs, and depending on the direction and degree of occurrence, the argon gas injection flow rate at the upper position of the discharge hole of the immersion nozzle can be adjusted to both directions. Straight flow of molten steel in a continuous casting mold characterized by controlling mold-like drift of molten steel by individually controlling the flow rate on the short side! ! This is the JI11 method.
また、本発明は、連続鋳造鋳型内の長辺幅方向の温度分
布を検出して、該温度分布または熱流束分布の鋳型の中
央部に対する右半分のパターンと左半分のパターンを比
較することにより、溶鋼偏流の発生の有無を検知し、そ
の発生方向および程度に応じて、タンプイソツユ上ノズ
ル位置および／またはスライディングノズル位置のアル
ゴンガス吹込み量を両短辺側で個別制御することにより
、鋳型的溶鋼偏流を制御することを特徴とする連続鋳造
鋳型内における溶鋼の偏流制御方法である。Further, the present invention detects the temperature distribution in the long side width direction within the continuous casting mold, and compares the pattern of the right half and the left half of the temperature distribution or heat flux distribution with respect to the center of the mold. , by detecting the occurrence of drifting of molten steel and individually controlling the amount of argon gas blown into the upper nozzle position and/or sliding nozzle position on both short sides according to the direction and degree of occurrence. This is a method for controlling the drift of molten steel in a continuous casting mold, which is characterized by controlling the drift of molten steel.
〈作 用〉
本発明によれば、連続鋳造鋳型内の長辺壁面の幅方向の
温度分布または熱流束分布を検出し、該温度分布または
熱流束分布の鋳型の中央部に対する右半分のパターンと
左半分のパターンとを比較することにより、溶鋼偏流の
発生の有無および偏流の程度が推定でき、その程度に応
じ浸漬ノズル上部位置のアルゴンガス流量を両短辺で個
別に流量制御することにより、あるいはタンデイツシュ
上ノズル位置および／またはスライディングノズル位置
のアルゴンガス吹込み量を両短辺側で個別制御すること
により溶鋼偏流を制御することができる。<Operation> According to the present invention, the temperature distribution or heat flux distribution in the width direction of the long side wall surface in the continuous casting mold is detected, and the pattern of the right half of the temperature distribution or heat flux distribution with respect to the center of the mold is determined. By comparing the pattern on the left half, it is possible to estimate the presence or absence of drifting of molten steel and the extent of drifting, and by individually controlling the argon gas flow rate at the upper position of the immersion nozzle on both short sides according to the extent, Alternatively, the drift of molten steel can be controlled by individually controlling the amount of argon gas blown into the nozzle position on the tundish and/or the sliding nozzle position on both short sides.
〈実施例〉
以下、本発明の実施例について、図面を参照しながら詳
しく説明する。<Examples> Examples of the present invention will be described in detail below with reference to the drawings.
第１図は、本発明に係わる実施例を示す模式的に示す斜
視図である。図に示すように、鋳型ｌの短辺１ａと長辺
１ｂのうち長辺幅方向に、複数の熱電対１０ａ〜１０ｅ
が埋め込まれ、これら熱電対ｌＯａ〜１０ｅで検出され
た溶鋼温度信号はそれぞれ例えばＡ／Ｄ変換ボードなど
の入力装置１１に入力され、さらにマイクロコンピュー
タなどの演算装置１２で演算処理され、その演算結果に
よる鋳型幅方向の温度分布は例えばＣＲＴなどの表示装
置１３に出力される。FIG. 1 is a schematic perspective view showing an embodiment of the present invention. As shown in the figure, a plurality of thermocouples 10a to 10e are arranged in the width direction of the short side 1a and the long side 1b of the mold l.
are embedded, and the molten steel temperature signals detected by these thermocouples lOa to 10e are each input to an input device 11 such as an A/D conversion board, and further processed by a calculation device 12 such as a microcomputer, and the calculation result is The temperature distribution in the width direction of the mold is output to a display device 13 such as a CRT.
第３図は、偏流が発生していない場合（ａ）と発生し場
合［有］）の鋳型幅方向の温度分布を示したものである
。（ａ）で示す偏流がない場合、鋳型長辺幅方向温度分
布はほぼ左右対称になっているのに対し、０））で示す
偏流が発生した場合、鋳型長辺幅方向の温度分布は左右
非対称となる（右側に偏流が発生した場合、右側よりの
温度が高くなる）現象を示している。FIG. 3 shows the temperature distribution in the width direction of the mold in the case (a) when no drifting occurs and the case (with) when drifting occurs. When there is no drift shown in (a), the temperature distribution in the long side width direction of the mold is almost symmetrical, whereas when the drift shown in 0)) occurs, the temperature distribution in the long side width direction of the mold is left and right. This shows an asymmetrical phenomenon (if a drift occurs on the right side, the temperature on the right side becomes higher).
第４図は、偏流の程度を推定する方法を説明するための
模式図である。すなわち、温度測定により得られた温度
分布に対し、最も低い温度測定値に整数の“１”を与え
、その測定値から高い値になるに従い順次大きくなる整
数値を付与し、鋳型中央から右半分の順位の和と左半分
の順位の和を比較し、その差でもって偏流の発生方向と
偏流の程度を推定するのである。FIG. 4 is a schematic diagram for explaining a method of estimating the degree of drift. In other words, for the temperature distribution obtained by temperature measurement, the lowest temperature measurement value is given an integer "1", and integer values that increase from that measurement value to higher values are given, and the right half from the center of the mold is given an integer value of 1. The sum of the ranks in the left half is compared with the sum of the ranks in the left half, and the difference is used to estimate the direction and degree of drift.
第５図は、この方法で導出した順位和の差（Ｏ印）と、
偏流により発生した鋳型的左右の溶鋼レベル差（×印）
の関係図である。ちなみに、特開昭６２−９３０５４号
公報で提示された方法に基づいて導出した溶鋼レベル差
も同時に比較例として示す。Figure 5 shows the difference between the rank sums derived using this method (marked with O), and
Difference in molten steel level on the left and right sides of the mold caused by drifting (x mark)
It is a relationship diagram. Incidentally, the molten steel level difference derived based on the method presented in JP-A No. 62-93054 is also shown as a comparative example.
同図より、順位和の差と実際の溶鋼レベル差がよく一致
しており、本発明法に基づく偏流の方向および程度の推
定がうまくいっていることを示している。The figure shows that the difference in rank sum and the actual molten steel level difference match well, indicating that estimation of the direction and degree of drift based on the method of the present invention is successful.
偏流の制御は、上述の方法で推定した偏流の方向および
程度に応じて、浸漬ノズル２の上部位置のアルゴンガス
流量を両短辺側で個別流量制御する方法を採用する。す
なわち第２図に示すように鋳型１の中央部に配置された
浸漬ノズル２の内面に垂直方向で左右に２分割した気体
吹込用のポーラス耐火物７を設けると共に、その背後に
ガス滞留空間１４を設け、不活性ガス供給管１５からガ
ス滞留空間１４を介してポーラス耐火物７に供給される
不活性ガス供給量を独立に制御する。To control the drift, a method is adopted in which the argon gas flow rate at the upper position of the submerged nozzle 2 is individually controlled on both short sides depending on the direction and degree of the drift estimated by the method described above. That is, as shown in FIG. 2, a porous refractory 7 for blowing gas is provided on the inner surface of the immersion nozzle 2 placed in the center of the mold 1, which is vertically divided into left and right halves, and a gas retention space 14 is provided behind it. are provided to independently control the amount of inert gas supplied from the inert gas supply pipe 15 to the porous refractory 7 via the gas retention space 14.
つまり、浸漬ノズル２の左右の吐出孔３ａ、３ｂの経時
変化により、浸漬ノズル２の左右の吐出流４と５の強さ
が不均一になった場合、吐出流５の弱い方へ多くの気体
を吹込み、逆に吐出流４の強い方へ少ない気体を吹込め
ば、気体の浮力によりガスリフト効果が鋳型ｌ内の左右
で相違し、多量の不活性ガスを吹込んだ側の上昇流５が
少量の不活性ガスを吹込んだ側の上昇流４より相対的に
強くなっている。In other words, if the strengths of the left and right discharge flows 4 and 5 of the submerged nozzle 2 become uneven due to changes over time in the left and right discharge holes 3a and 3b of the submerged nozzle 2, more gas will flow to the weaker discharge flow 5. If a small amount of gas is blown into the stronger side of the discharge flow 4, the gas lift effect will be different on the left and right sides of the mold 1 due to the buoyancy of the gas, resulting in an upward flow 5 on the side where a large amount of inert gas has been blown. is relatively stronger than the upward flow 4 on the side into which a small amount of inert gas is blown.
かくして吐出孔４．５の強さの不均一になる上昇流の強
さの不均一つまり偏流を前述のように鋳型１の長辺幅方
向の温度分布で検知し、この検知した値に基づいてガス
流量制御装置８を介して不活性ガス供給管１１に設けた
流Ｉｖｉ４節弁９を調節し、ガス滞留空間１０からポー
ラス耐火物７を通して上昇流の弱い方へ多量の不活性ガ
スを吹込めば、吐出流４．５の強度の不均一による上昇
流４Ａ、５Ａの不均一が解消され、鋳型ｌ内の偏流がな
くなる。As described above, the uneven strength of the upward flow resulting in the uneven strength of the discharge hole 4.5, that is, the uneven flow, is detected by the temperature distribution in the long side width direction of the mold 1, and based on this detected value. Adjust the flow Ivi four-node valve 9 provided in the inert gas supply pipe 11 via the gas flow rate control device 8, and blow a large amount of inert gas from the gas retention space 10 through the porous refractory 7 to the side where the upward flow is weak. For example, the non-uniformity of the upward flows 4A and 5A due to the non-uniformity of the intensity of the discharge flow 4.5 is eliminated, and the uneven flow within the mold 1 is eliminated.
第１表に長辺幅方向温度分布から導出した、右半面順位
和と左反面順位和の差（ΔＳ）と各ΔＳに対して、ΔＳ
を適正範囲内に制御するために、変化させるべきアルゴ
ンガス流量変化量（ΔＱ）の関係を示す、
第１表
この第１表に基づき、浸漬ノズル２からのアルゴンガス
流量を両短片側で個別流量制御することで、？８鋼偏流
が抑制できる。Table 1 shows the difference (ΔS) between the right half side rank sum and the left half side rank sum derived from the temperature distribution in the long side width direction, and for each ΔS, ΔS
Table 1 shows the relationship between the amount of change in argon gas flow rate (ΔQ) that should be changed in order to control the argon gas flow rate within an appropriate range. By controlling the flow rate? 8 Steel drift can be suppressed.
本発明を実施した場合を第７回を用いて説明する。鋳造
開始して７０分間位は、右半面順位和から左半面順位和
を差し引いた差△Ｓの絶対値が２以下と低位安定してお
り、鋳型的溶鋼流動は左右均等であることがうかがえる
（ΔＳの適正範囲は±４以内）。その後、ΔＳが正方向
に大きく推移しく右側に偏流したことを示唆）、その時
に浸漬ノズル右側へのアルゴンガス２ＲＩＱ（右）を、
通常操業時のアルゴンガス滓量３ Ｎｌ ／ ｍから１
．５Ｎｌ／１に減少させ（この場合ΔＱ＝ １．５ＮＺ
／飾）、逆に反偏流側である左側へのアルゴンガスｔＡ
ｆｆｉＱ（左）峻３Ｎｌ／廟から４ 、５ ＮＺ ／鮨
に増加させたとこ入 △Ｓが適正範囲内に戻った。この
操作により、鋳型的溶鋼流動が均等に戻った秤考えられ
る。A case in which the present invention is implemented will be explained using the seventh session. For about 70 minutes after the start of casting, the absolute value of the difference △S, which is the difference between the sum of ranks on the right half and the sum of ranks on the left half, remains low and stable at 2 or less, indicating that the mold-like flow of molten steel is equal on the left and right sides ( The appropriate range of ΔS is within ±4). After that, ΔS significantly changed in the positive direction, suggesting that the flow was drifting to the right), and at that time, argon gas 2RIQ (right) was sent to the right side of the immersion nozzle.
Argon gas slag amount during normal operation: 3 Nl/m to 1
．． 5Nl/1 (in this case ΔQ= 1.5NZ
/ Decoration), conversely, argon gas tA to the left side, which is the anti-drift side.
ffiQ (left) Increased from Shun 3Nl/Myo to 4,5 NZ/Sushi. △S has returned to the appropriate range. It is thought that this operation returned the mold-like flow of molten steel to an even level.
その後、ΔＳが負方向に大きく推移（右側に偏流したこ
とを示唆）したが、同様に浸漬ノズル左側の流量を減少
させ、浸漬５ノズル左側の流量を増加させることによっ
てΔＳが再度適正範囲内に戻り、鋳型的溶鋼流動が均等
化された。この実験は、ΔＳが大きく変移した場合に、
ΔＳを適正範囲内に戻すためには、浸漬ノズル左右から
吹き込むアルゴンガス流量にどの程度の差をつければよ
いかを把握するために行ったものであり、同様の実験を
実施して結果をまとめたものが第１表である。After that, ΔS significantly changed in the negative direction (suggesting that the flow was drifting to the right), but by similarly decreasing the flow rate on the left side of the immersion nozzle and increasing the flow rate on the left side of the immersion 5 nozzle, ΔS was brought back within the appropriate range. Returning, the mold-like flow of molten steel was equalized. In this experiment, when ΔS changes significantly,
This was done in order to understand how much difference should be made in the flow rate of argon gas blown from the left and right sides of the immersion nozzle in order to return ΔS to within the appropriate range.We conducted similar experiments and summarized the results. Table 1 shows the results.
第１表により、ΔＳを適正範囲内に制御するための、浸
漬ノズルの左右アルゴンガス流量差が決定することがで
きる。From Table 1, it is possible to determine the difference in the flow rate of argon gas between the left and right sides of the submerged nozzle in order to control ΔS within an appropriate range.
次に、本発明を鋳造開始から適用した場合の実験結果を
第８図に示す、第８図から、偏流の発生サイドおよび程
度の指標であるΔＳを常時監視（但し、サンプリング周
期は約１０秒）し、この値と浸漬ノズル左右のアルゴン
ガス流量個別制御を組み合わせることにより、ΔＳが適
正範囲内に収まり、鋳型的溶鋼偏流が抑制されているの
がわかる。Next, Figure 8 shows the experimental results when the present invention is applied from the start of casting. From Figure 8, ΔS, which is an index of the occurrence side and degree of drift, is constantly monitored (however, the sampling period is approximately 10 seconds). ), and it can be seen that by combining this value with individual control of the argon gas flow rates on the left and right sides of the immersion nozzle, ΔS falls within an appropriate range, and mold-like molten steel drift is suppressed.
なお第６図に、偏流制御実施前と実施後の鋳片品質の状
況を示す０本発明法の通用により、鋳片品質は大幅に改
善されていることがわかる。FIG. 6 shows the quality of slabs before and after the implementation of drift control. It can be seen that the quality of slabs has been significantly improved by applying the method of the present invention.
鋳型の長辺幅方向の温度分布により鋳型内の偏流を制御
手段としては前述実施例の他に、偏流の方向およびその
程度に応Ｉユてタンディッシュ上ノズル部および／また
はスライディングノズル部位置”のアルゴンガス流量を
両短辺側で個別流量制御する方法を採用することができ
る。In addition to the above-mentioned embodiments, means for controlling the uneven flow inside the mold by controlling the temperature distribution in the long side width direction of the mold can be used to control the position of the nozzle part on the tundish and/or the sliding nozzle part depending on the direction and degree of the uneven flow. It is possible to adopt a method of individually controlling the argon gas flow rate on both short sides.
第９図においてクンデインシュ１Ｇに設けられたタンデ
イツシュ上ノズル１７の内部には左右一対の半円状分割
スリン）１８ａ、１８ｂ（第１０図参照）が設けてあり
、半円状分割スリン）１８ａ、１８ｂの内側には通気性
のポーラスれんが１９が設けである。In FIG. 9, a pair of left and right semicircular divided sulins) 18a, 18b (see FIG. 10) are provided inside the tundish upper nozzle 17 provided in the kundeinshu 1G. There are permeable porous bricks 19 inside.
またスライディングノズル２０の固定プレート２０ａの
内部にも第１０図に示すものに準して左右一対の半円状
分割スリット２１ａ、２１ｂが設けてあり、半円状分割
スリット２１ａ、２１ｂの内側にも通気性ポーラスれん
が１９が設けである。Also, inside the fixed plate 20a of the sliding nozzle 20, a pair of left and right semicircular dividing slits 21a, 21b are provided according to the one shown in FIG. Air permeable porous bricks 19 are provided.
半円状分割スリン）１８ａ、１８ｂならびに半円状分割
スリン）２１ａ、２１ｂにはそれぞれガス供給管１５が
接続されると共に、ガス供給管Ｉ５には流量調節弁９が
配設されていて個別に制御されるようになっている。A gas supply pipe 15 is connected to each of the semicircular divided sulins) 18a, 18b and the semicircular divided sulins) 21a, 21b, and a flow rate control valve 9 is disposed in the gas supply pipe I5 to individually It's about to be controlled.
ガス流量制？１１装置８は熱電対１０ａ〜１０ｅによる
鋳型１の長辺幅方向温度分布によって各流！調節弁９の
開度が調節され、不活性ガス供給管１５から半円状分割
スリｙトｉ８ａおよび２１ａに供給されるアルゴンガス
等のト活性ガスと、ガス供給管１５から半円状分割スリ
、ト１．８ｂおよび２１ａ＆世給されるアルゴンガス等
の不活性ガスとの各つ”ス流量が独立に１ｉ１節され、
通気性ポーラスれんが１９から吹込まれる左右の不活性
ガス流量が調整される。Gas flow rate system? 11 device 8 uses thermocouples 10a to 10e to determine the temperature distribution in the long side width direction of mold 1. The opening degree of the control valve 9 is adjusted, and active gas such as argon gas is supplied from the inert gas supply pipe 15 to the semicircular divided slits i8a and 21a, and the semicircular divided slits are supplied from the gas supply pipe 15 to the semicircular divided slits i8a and 21a. , 1.8b and 21a & the flow rate of each inert gas such as argon gas to be supplied is independently set 1i1,
The flow rates of the left and right inert gases blown into the air-permeable porous bricks 19 are adjusted.
前記の場合、タンデイ、シュ上ノズル１７に設けた半円
状分割ス１１ソト１８ａ、１８ｂの内側に通気性ポーラ
スれんが１９を設けるものについて説明しまたが、第１
１図に示すように半円状分割スリン）１２ａ、１２ｂに
連通さセて内側に複数のガス吹込用細管２２を配設して
不活性ガスを吹込むようにしてもよい。In the above case, the case where the breathable porous bricks 19 are provided inside the semicircular divided slots 18a and 18b provided on the upper nozzle 17 will be described.
As shown in FIG. 1, a plurality of gas blowing thin tubes 22 may be arranged inside the semicircular divided sulins 12a and 12b to blow inert gas therein.
次に本発明の作用について説明すると、鋳型２の長辺幅
方向にそれぞれ埋設した複数の熱電対１０ａ〜１０ｅに
よって検出された長辺幅方向温度分布により監視され、
流量１！節弁９の開度を調節する。Next, to explain the operation of the present invention, the temperature distribution in the long side width direction detected by a plurality of thermocouples 10a to 10e embedded in the long side width direction of the mold 2 is monitored,
Flow rate 1! Adjust the opening degree of the control valve 9.
かくして、不活性ガス供給管１５から半円状スリット１
８ａおよび２１ａに供給される不活性ガス量とガス供給
管１５から半円状スリッ目８ｂおよび２１ｂに供給され
る不活性ガス量を調整し、通気性ポーラスれんが１３か
ら吹込まれる左右の不活性ガス流量を変化させる。Thus, the semicircular slit 1 is formed from the inert gas supply pipe 15.
The amount of inert gas supplied to 8a and 21a and the amount of inert gas supplied from gas supply pipe 15 to semicircular slits 8b and 21b are adjusted, and the left and right inert gases blown from air permeable porous brick 13 are adjusted. Change gas flow rate.
例えば、浸漬ノズル２の左側の吐出孔３ａがらの流速が
右側の吐出孔３ｂよりも大きい場合、通気性ポーラスれ
んが３の左側から吹込まれる不活性ガス量を増量し、右
側から吹込まれる不活性ガス量を減量すると鋳型１内に
注入される溶１ｉｉ１６の偏流が解消される。For example, if the flow velocity through the discharge hole 3a on the left side of the immersion nozzle 2 is higher than that through the discharge hole 3b on the right side, the amount of inert gas blown from the left side of the breathable porous brick 3 is increased, and the amount of inert gas blown from the right side is increased. By reducing the amount of active gas, the uneven flow of the melt 1ii16 injected into the mold 1 is eliminated.
前述第９図に示すタンデイツシュノズルおよび／または
固定プレートから不活性ガスを吹込むものは、第２図に
示す浸漬ノズルから不活性ガスを吹込むものに比較して
損傷が少なく寿命が長いという利点がある。The device that blows inert gas from the tundish nozzle and/or fixed plate shown in Figure 9 has less damage and has a longer life than the one that blows inert gas from the submerged nozzle shown in Figure 2. There is an advantage.
〈発明の効果〉
以上説明したように本発明によれば浸漬ノズルの吐出孔
を介して鋳型に注入された溶鋼の偏流を容易に防止する
ことうくできる。その結果、鋳型内溶鋼の偏流に起因す
るフラックス巻込み等による鋳片の欠陥を大幅に低減で
きる。<Effects of the Invention> As explained above, according to the present invention, drifting of molten steel injected into a mold through the discharge hole of the immersion nozzle can be easily prevented. As a result, defects in the slab due to flux entrainment caused by drifting of molten steel in the mold can be significantly reduced.
第１図は本発明に係る鋳型長辺幅方向の温度測定手段を
模式的に示す斜視図、第２図は本発明に係る偏流防止手
段を示す断面図、第３図および第４図は鋳型長辺幅方向
の温度分布を示す線グラフ、第５図は実際の鋳型溶鋼レ
ベル差と順位和の差（ΔＳ）との関係を示ず線グラフ、
第６図は鋳片品質指標を本発明例と従来例について比較
する棒グラフ、第７図および第８図は鋳型長辺の幅方向
の右側順位和から左側順位和を差し引いた順位和差ΔＳ
および左右の各ガス流量の各経時変化を示す線グラフ、
第９図は本発明に係る偏流防止の他の手段を示す断面図
、第１０図は第９図のＡ−Ａ矢視を示すタンデイツシュ
上ノズルの断面図、第１１図は本発明に係るタンデイツ
シュ上ノズルの他の例を示す断面図、第１２図は従来の
鋳型へのＲ１１Ａ注入状況を示す断面図である。
１・・・鋳 型、 ２・・・浸漬ノズル、３
・・・吐出孔、
４．５・・・溶鋼流動方向を示す矢印、６・・・溶 鋼
、 ７・・・ポーラス耐火物、８・・・ガス
流量制御装置、９・・・流量調節弁、ＩＯ・・・熱電対
、 １１・・・入力装置、１２・・・演算装置
、 １３・・・表示装置、Ｉ４・・・ガス滞留空
間、 １５・・・不活性ガス供給管、１６・・・タン
デイツシュ、 １７・・・上ノズル、１日・・・スリッ
ト、 １９・・・ポーラスれんが、２０・・・ス
ライディングノズル、
２１・・・スリット、 ２２・・・ガス吹込管。FIG. 1 is a perspective view schematically showing a temperature measuring means in the long side width direction of a mold according to the present invention, FIG. 2 is a sectional view showing a drift prevention means according to the present invention, and FIGS. 3 and 4 are a mold A line graph showing the temperature distribution in the long side width direction, Figure 5 is a line graph showing the relationship between the actual mold molten steel level difference and the rank sum difference (ΔS),
Figure 6 is a bar graph comparing slab quality indicators for the inventive example and the conventional example, and Figures 7 and 8 are the rank sum difference ΔS obtained by subtracting the left rank sum from the right rank sum in the width direction of the long side of the mold.
and a line graph showing changes over time in each gas flow rate on the left and right sides,
FIG. 9 is a cross-sectional view showing another means for preventing drifting according to the present invention, FIG. 10 is a cross-sectional view of the upper nozzle of the tundish dish taken along the line A-A in FIG. 9, and FIG. FIG. 12 is a cross-sectional view showing another example of the upper nozzle, and FIG. 12 is a cross-sectional view showing the state of R11A injection into a conventional mold. 1... Mold, 2... Immersion nozzle, 3
...Discharge hole, 4.5...Arrow indicating the flow direction of molten steel, 6... Molten steel, 7...Porous refractory, 8...Gas flow rate control device, 9...Flow rate adjustment valve , IO... thermocouple, 11... input device, 12... computing device, 13... display device, I4... gas retention space, 15... inert gas supply pipe, 16... - Tanditetsu, 17... Upper nozzle, 1st... Slit, 19... Porous brick, 20... Sliding nozzle, 21... Slit, 22... Gas blowing pipe.
Claims (1)
、該温度分布または熱流束分布の鋳型の中央部に対する
右半分のパターンと左半分のパターンを比較することに
より、溶鋼偏流の発生の有無を検知し、その発生方向お
よび程度に応じて、浸漬ノズルの吐出孔上部位置のアル
ゴンガス吹込み流量を両短辺側で個別流量制御すること
により、鋳型内溶鋼偏流を制御することを特徴とする連
続鋳造鋳型内における溶鋼の偏流制御方法。 ２、連続鋳造鋳型内の長辺幅方向の温度分布を検出して
、該温度分布または熱流束分布の鋳型の中央部に対する
右半分のパターンと左半分のパターンを比較することに
より、溶鋼偏流の発生の有無を検知し、その発生方向お
よび程度に応じて、タンディッシュ上ノズル位置および
／またはスライディングノズル位置のアルゴンガス吹込
み量を両短辺側で個別制御することにより、鋳型内溶鋼
偏流を制御することを特徴とする連続鋳造鋳型内におけ
る溶鋼の偏流制御方法。[Claims] 1. Detecting the temperature distribution in the long side width direction within the continuous casting mold, and comparing the right half pattern and the left half pattern of the temperature distribution or heat flux distribution with respect to the center of the mold. By this, it is possible to detect whether or not a molten steel drift has occurred, and to control the flow rate of argon gas blowing at the upper position of the discharge hole of the submerged nozzle on both short sides individually depending on the direction and degree of occurrence. A method for controlling the drift of molten steel in a continuous casting mold, the method comprising controlling the drift of molten steel. 2. By detecting the temperature distribution in the long side width direction in the continuous casting mold and comparing the pattern of the right half and the left half of the temperature distribution or heat flux distribution with respect to the center of the mold, it is possible to detect the uneven flow of molten steel. By detecting the presence or absence of occurrence and controlling the amount of argon gas blown into the tundish upper nozzle position and/or sliding nozzle position individually on both short sides depending on the direction and degree of occurrence, it is possible to prevent molten steel drift in the mold. A method for controlling the drift of molten steel in a continuous casting mold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2219096A JP2962788B2 (en) | 1990-08-22 | 1990-08-22 | Control method of drift of molten steel in continuous casting mold |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2219096A JP2962788B2 (en) | 1990-08-22 | 1990-08-22 | Control method of drift of molten steel in continuous casting mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04105756A true JPH04105756A (en) | 1992-04-07 |
| JP2962788B2 JP2962788B2 (en) | 1999-10-12 |
Family
ID=16730198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2219096A Expired - Lifetime JP2962788B2 (en) | 1990-08-22 | 1990-08-22 | Control method of drift of molten steel in continuous casting mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2962788B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000051763A1 (en) * | 1999-03-02 | 2000-09-08 | Nkk Corporation | Method and device for estimating/controlling molten steel flowing pattern in continuous casting |
| KR100516028B1 (en) * | 1999-03-02 | 2005-09-26 | 제이에프이 스틸 가부시키가이샤 | Method and device for estimating/controlling molten steel flowing pattern in continuous casting |
| JP2006231375A (en) * | 2005-02-25 | 2006-09-07 | Jfe Steel Kk | Method for continuously casting steel |
-
1990
- 1990-08-22 JP JP2219096A patent/JP2962788B2/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2000051763A1 (en) * | 1999-03-02 | 2000-09-08 | Nkk Corporation | Method and device for estimating/controlling molten steel flowing pattern in continuous casting |
| WO2000051762A1 (en) * | 1999-03-02 | 2000-09-08 | Nkk Corporation | Method and device for predication and control of molten steel flow pattern in continuous casting |
| EP1166921A1 (en) * | 1999-03-02 | 2002-01-02 | Nkk Corporation | Method and device for estimating/controlling molten steel flowing pattern in continuous casting |
| US6712122B2 (en) | 1999-03-02 | 2004-03-30 | Nkk Corporation | Method for estimating and controlling flow pattern of molten steel in continuous casting and apparatus therefor |
| EP1166921A4 (en) * | 1999-03-02 | 2004-08-18 | Jfe Steel Corp | Method and device for estimating/controlling molten steel flowing pattern in continuous casting |
| KR100516028B1 (en) * | 1999-03-02 | 2005-09-26 | 제이에프이 스틸 가부시키가이샤 | Method and device for estimating/controlling molten steel flowing pattern in continuous casting |
| JP2006231375A (en) * | 2005-02-25 | 2006-09-07 | Jfe Steel Kk | Method for continuously casting steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2962788B2 (en) | 1999-10-12 |
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