JPS6347545B2 - - Google Patents
Info
- Publication number
- JPS6347545B2 JPS6347545B2 JP57031883A JP3188382A JPS6347545B2 JP S6347545 B2 JPS6347545 B2 JP S6347545B2 JP 57031883 A JP57031883 A JP 57031883A JP 3188382 A JP3188382 A JP 3188382A JP S6347545 B2 JPS6347545 B2 JP S6347545B2
- Authority
- JP
- Japan
- Prior art keywords
- breakout
- temperature
- mold
- thermocouple
- shell
- 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
- 230000008859 change Effects 0.000 claims description 31
- 238000000034 method Methods 0.000 claims description 25
- 238000009749 continuous casting Methods 0.000 claims description 8
- 230000008569 process Effects 0.000 description 15
- 238000005266 casting Methods 0.000 description 10
- 238000001514 detection method Methods 0.000 description 7
- 230000007704 transition Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229910000831 Steel Inorganic materials 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000010959 steel Substances 0.000 description 4
- 230000005856 abnormality Effects 0.000 description 3
- 238000009529 body temperature measurement Methods 0.000 description 3
- 230000005499 meniscus Effects 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/16—Controlling or regulating processes or operations
- B22D11/20—Controlling or regulating processes or operations for removing cast stock
- B22D11/207—Controlling or regulating processes or operations for removing cast stock responsive to thickness of solidified shell
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
Description
【発明の詳細な説明】
本発明は拘束性ブレイクアウト予知方法に係
り、詳しくは、連続鋳造鋳型内に熱電対を埋め込
んでその温度変化を検出し、その変化の推移と温
度変化の検出順序パターンをチエツクすることに
より、拘束性ブレイクアウトを予知し、未然に防
止する方法に係る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for predicting a restraining breakout, and more particularly, a thermocouple is embedded in a continuous casting mold to detect temperature changes, and the transition of the change and the detection order pattern of the temperature change are disclosed. This relates to a method for predicting and preventing a restrictive breakout by checking.
近年、連続鋳造設備は高速化、高品質化を指向
しており、モールドメツキ、浸漬ノズル形状その
他鋳造条件は大巾に変化している。それに伴い操
業事故は多様化し、各種、改善開発にも拘らず減
少していない。操業事故の中でも最も問題となる
のは、ブレイクアウトである。従来のブレイクア
ウトは多くの場合、温度異常、鋳造速度急変、パ
ウダー不適、マシン不整等の操業条件に異常が認
められる場合に発生している。これらのブレイク
アウトは、技術の発展とともに減少している。し
かし、近年のブレイクアウトは、従来のブレイク
アウトと相違して操業条件に表面的な異常は認め
られないにも拘らず、突然発生するものであり、
その対策に苦慮している。この種のブレイクアウ
トで特徴的なことは、いずれもシエルがモールド
に固着し、シエルがひきちぎられてブレイクアウ
トに至ることであつて、従来のブレイクアウトと
区別する意味で拘束性ブレイクアウトと考えられ
る。 In recent years, continuous casting equipment has been oriented toward higher speed and higher quality, and mold plating, immersion nozzle shape, and other casting conditions have changed drastically. As a result, operational accidents have become more diverse and have not decreased despite various improvements and developments. Breakouts are the most problematic type of operational accident. Conventional breakouts often occur when abnormal operating conditions are recognized, such as temperature abnormalities, sudden changes in casting speed, inappropriate powder, or machine irregularities. These breakouts are decreasing as technology develops. However, unlike traditional breakouts, breakouts in recent years occur suddenly, even though there is no apparent abnormality in operating conditions.
I'm having trouble finding a way to deal with it. A characteristic feature of this type of breakout is that the shell sticks to the mold, and the shell is torn off, leading to a breakout. This is called a restrictive breakout to distinguish it from a conventional breakout. Conceivable.
この拘束性ブレイクアウトの原因としてパウダ
ーの流入不良が考えられるが、これ以外に多くの
要因に左右され、パウダーの開発過程においても
拘束性ブレイクアウトを防止することが望まれて
いる。 Although the cause of this restrictive breakout is thought to be poor inflow of powder, it is influenced by many other factors, and it is desired to prevent restrictive breakout during the powder development process as well.
本発明は、上記欠点の解決を目的とし、具体的
には上記の拘束性ブレイクアウト発生を事前に防
止できるブレイクアウト予知方法を提案する。 The present invention aims to solve the above-mentioned drawbacks, and specifically proposes a breakout prediction method that can prevent the occurrence of the above-mentioned restrictive breakout in advance.
すなわち、本発明は連続鋳造設備の鋳造壁面に
複数の熱電対を埋設し、これら熱電対中の一つの
熱電対の検出温度が検出平均温度より、一旦上昇
してから下降したことを検出し、この一つの熱電
対に隣接した他の少なくとも一つの熱電対で、続
いて上記検出温度の温度変化パターンが検出され
たときを、ブレイクアウト発生として予知するこ
とを特徴とする。 That is, the present invention embeds a plurality of thermocouples in the casting wall surface of continuous casting equipment, and detects when the detected temperature of one of these thermocouples rises once and then falls from the detected average temperature, The present invention is characterized in that the occurrence of a breakout is predicted when the temperature change pattern of the detected temperature is subsequently detected in at least one other thermocouple adjacent to this one thermocouple.
以下、本発明について詳しく説明する。 The present invention will be explained in detail below.
まず、連続鋳造において、その鋳型におけるブ
レイクアウトの発生状況をみると、拘束性ブレイ
クアウトではシエルが鋳型内で破断残存している
ことがわかる。このため、本発明者等はこの現象
から拘束性ブレイクアウトの発生過程を調べたと
ころ次の通りであることがわかつた。 First, when looking at the occurrence of breakouts in the mold during continuous casting, it is found that in the case of restraint breakouts, the shell is broken and remains in the mold. For this reason, the present inventors investigated the process of occurrence of restrictive breakout based on this phenomenon and found the following.
すなわち、第１図ａ，ｂ，ｃ，ｄ，ｅならびに
ｆは拘束性ブレイクアウト発生過程の説明図であ
つて、第１にシエル１の一部が何らかの原因で鋳
型２の壁面に固着される（第１図ａ参照）。 That is, FIGS. 1a, b, c, d, e, and f are explanatory diagrams of the process of generating a restrictive breakout. First, a part of the shell 1 is stuck to the wall surface of the mold 2 for some reason. (See Figure 1a).
第２に、鋳込み引抜きによりシエル１の弱い部
分１ａ、つまり固着部１ａの直下でシエル１がひ
きちぎられる（第１図ｂ参照）。 Secondly, the shell 1 is torn off at the weak part 1a of the shell 1, that is, directly below the fixed part 1a (see FIG. 1b).
第３に、ちぎられた部分１ａに溶鋼が矢印の通
りに侵入し、鋳型２と接触凝固する（第１図ｃ参
照）。 Third, molten steel enters the torn portion 1a in the direction of the arrow and solidifies in contact with the mold 2 (see FIG. 1c).
第４に、鋳込み引抜きによりシエル１の弱い部
分１ａ、つまり凝固部分がひきちぎられる（第１
図ｄ参照）。 Fourth, the weak part 1a of the shell 1, that is, the solidified part, is torn off by casting and drawing (the first
(see figure d).
従つて、以上の通りの第１〜第４の各過程を繰
り返すことにより凝固シエルのひきちぎられる位
置は、順次に鋳型の下方へ移動し、これに伴い固
着シエルは凝固厚が厚くなつて、第１図ｅの通り
に面積的に成長する。 Therefore, by repeating each of the first to fourth processes as described above, the position where the solidified shell is torn off sequentially moves below the mold, and as a result, the solidified thickness of the solidified shell becomes thicker. The area grows as shown in Figure 1e.
また、凝固シエルのひきちぎられる位置が第１
図ｆの通りにモールド直下近傍に到つた場合にブ
レイクアウトとなる。 Also, the position where the coagulated shell is torn is the first
As shown in Fig. f, when it reaches the vicinity directly under the mold, a breakout occurs.
また、以上の通り鋳型２の上下方向にシエルの
破断部１ａの位置は、下方へ移動するが、これと
同時にシエルの破断部の位置は鋳型の横方向へも
伝播波及し、これが重なつて上記の如くブレイク
アウトのときにシエルが鋳型内に残存する。そこ
で、上記知見事実にもとづいて、第１図ａ〜ｆの
Ａ部分の温度を測定し、この温度推移と第１図ａ
〜ｆの各過程との相関性を求めたところ、この温
度推移によつて各過程が適格に把握でき、ブレイ
クアウトが予知できることがわかつた。 Further, as described above, the position of the broken part 1a of the shell moves downward in the vertical direction of the mold 2, but at the same time, the position of the broken part of the shell also propagates and spreads in the lateral direction of the mold, and this overlaps. As mentioned above, the shell remains in the mold upon breakout. Therefore, based on the above knowledge and facts, we measured the temperature of part A in Figure 1 a to f, and compared this temperature transition and Figure 1 a.
When the correlation with each process of ~f was determined, it was found that each process can be properly understood from this temperature transition, and breakout can be predicted.
すなわち、第２図は上記過程でブレイクアウト
が発生する際の第１図ａ〜ｆのＡ部分の一つの熱
電対での温度変化の推移を示すグラフである。第
２図において、第１図ａ〜ｄでの各過程でシエル
の破断部が推移している間は、温度はほぼ一定の
温度、つまり、検出平均温度で推移する。この破
断部が下方に移動し、第１図ｅのところに至ると
高温度となり、その後は、鋳型壁面に凝固残存し
たシエル部位は成長すると共に、鋳型と鋳片間の
伝熱特性の変化（パウダー固化エアギヤツプ生成
による）によつて大きな温度降下が第２図の如く
生じる。また、拘束性ブレイクアウトの発生に
は、鋳型温度にピーク値が存在することから、鋳
型の温度分布を測定するとブレイクアウト直前に
温度分布の異常が認められ、温度のピーク値が発
生し、そのピーク値を測定すれば予知できること
も考えられる。しかし、実際にはこのピーク値は
測定位置や鋼種によつて相違するが、その温度差
は15〜20℃程度であり、この程度の温度差では、
測定時の湯面変動等の場合と区別することが困難
であり、ピーク値の測定のみによつてブレイクア
ウトを予知することは困難である。 That is, FIG. 2 is a graph showing the transition of temperature change in one thermocouple in portion A of FIG. 1 a to f when a breakout occurs in the above process. In FIG. 2, while the broken portion of the shell changes in each process shown in FIGS. 1A to 1D, the temperature changes at a substantially constant temperature, that is, the detected average temperature. When this fractured part moves downward and reaches the point e in Figure 1, the temperature becomes high, and after that, the shell part solidified and remaining on the mold wall grows, and the heat transfer characteristics between the mold and the slab change ( Due to powder solidification air gap formation), a large temperature drop occurs as shown in FIG. In addition, when a restrictive breakout occurs, there is a peak value in the mold temperature, so when the temperature distribution of the mold is measured, an abnormality in the temperature distribution is observed just before the breakout, and a peak temperature value occurs. It is conceivable that prediction can be made by measuring the peak value. However, in reality, this peak value differs depending on the measurement location and steel type, but the temperature difference is about 15 to 20 degrees Celsius, and with a temperature difference of this degree,
It is difficult to distinguish this from cases such as fluctuations in the hot water level during measurement, and it is difficult to predict breakout only by measuring the peak value.
この点から本発明者等は、ブレイクアウト発生
過程における鋳型温度の降下パターンに着目重視
して研究したところ、この温度降下パターンを検
出することによつて、まず、シエル破断部の鋳型
測温点通過を判定し、つぎにこの温度変化パター
ンが隣接する測温点に波及して少なくとも連続し
て２個以上の熱電対で、このような温度変化パタ
ーンを検出するとブレイクアウトを予知できるこ
とがわかつた。 From this point of view, the present inventors conducted research focusing on the drop pattern of mold temperature during the breakout generation process, and by detecting this temperature drop pattern, we first determined It was found that a breakout can be predicted by determining the passage of a temperature change pattern and then detecting such a temperature change pattern with at least two or more consecutive thermocouples as this temperature change pattern spreads to adjacent temperature measurement points. .
換言すると、鋳型壁面に熱電対を埋設して温度
変化を検出する際に、そのピークの値のみを検出
するのでなく、測定温度がピーク値を経て急激に
温度降下を生じたとき、つまり、この温度降下パ
ターンを連続して２つ以上の隣接する熱電対で検
出してブレイクアウトを予知する。 In other words, when detecting temperature changes by embedding thermocouples in the mold wall, we do not only detect the peak value, but also detect when the measured temperature suddenly drops after reaching the peak value. A breakout is predicted by sequentially detecting a temperature drop pattern with two or more adjacent thermocouples.
この連続する２つ以上の隣接する熱電対で、温
度変化パターンを検出してブレイクアウト予知す
るという方法は、ブレイクアウト発生過程におい
ては、必ず凝固シエルの破断面が除々に伝播波及
するという仕組みに着目したものである。なお、
一つの熱電対のみの温度変化パターンでブレイク
アウトを予知すると、エアーギヤツプ及び連鋳操
業時の継ぎたし等に対して生ずることのある所謂
段注ぎ等の発生による影響でも、その発生箇所の
通過によつて温度降下の変化パターンが熱電対に
より検出され、誤まつたブレイクアウト予知とな
り、実操業への影響が大きいことから絶対にさけ
る必要がある。この点、本発明では初期に温度の
降下パターンを検出した熱電対に隣接した熱電対
によつて、続いて同じ温度降下パターンが検出さ
れたことをもつて、ブレイクアウト予知を行なう
ため、上述誤判定なく正しくブレイクアウトが予
知できる。 This method of predicting a breakout by detecting a temperature change pattern using two or more consecutive adjacent thermocouples is based on a mechanism in which the fracture surface of the solidified shell always propagates and spreads gradually during the breakout occurrence process. This is what we focused on. In addition,
If a breakout is predicted based on the temperature change pattern of only one thermocouple, it is possible to predict the breakout by passing through the point where the breakout occurs, even if it is affected by so-called step pouring, which can occur due to air gaps or joints during continuous casting operations. Therefore, the change pattern of temperature drop is detected by the thermocouple, resulting in a false breakout prediction, which must be avoided at all costs as it has a large impact on actual operations. In this regard, in the present invention, breakout prediction is performed based on the subsequent detection of the same temperature drop pattern by a thermocouple adjacent to the thermocouple that initially detected the temperature drop pattern. Breakouts can be predicted accurately without judgment.
すなわち、エアーギヤツプ、段注ぎの発生は部
分的であつて、隣接する二つの熱電対に対して影
響を及ぼすほど大きなものは通常発生せず、従つ
て、隣接する２つの熱電対での検出による判定で
正確に予知され、また、隣接熱電対に影響を及ぼ
す大きなエアーギヤツプ、段注ぎが発生した際
は、鋳型直下でブレイクアウトに至つており、誤
判定とはならない。 In other words, air gaps and step pouring occur only partially, and usually do not occur large enough to affect two adjacent thermocouples. In addition, when a large air gap or step pouring that affects adjacent thermocouples occurs, a breakout occurs directly under the mold, so it is not an erroneous judgment.
この際、熱電対はブレイクアウト発生過程と関
連して熱電対を適正位置に埋め込むのが好まし
い。 At this time, it is preferable to embed the thermocouple at a proper position in relation to the breakout generation process.
まず、第３図は300×400mmサイズで長さ700mm
の鋳型において、鋳型上端から200mmで４つの各
壁面巾方向中央の測定位置に各１本の熱電対を配
設して、ブレイクアウト発生時の各熱電対測定デ
ータを鋳造時間との関係から示したものである
（ただし、B.O発生とは拘束性ブレイクアウトの
発生を示す。）。第３図の左欄には熱電対の配設鋳
型壁面を示し、はじめに３面側で温度の急激な上
昇と下降が起こり、続いて４面側、２面側、１面
側の順で発生していることがわかる。 First, Figure 3 has a size of 300 x 400 mm and a length of 700 mm.
In this mold, one thermocouple was placed at the center of each of the four wall widths at a distance of 200 mm from the top of the mold, and the measurement data of each thermocouple at the time of breakout was shown in relation to the casting time. (However, BO occurrence indicates the occurrence of a restrictive breakout.) The left column of Fig. 3 shows the wall surface of the mold where the thermocouple is installed, and a rapid rise and fall in temperature occurs first on the 3rd side, then on the 4th side, the 2nd side, and the 1st side in that order. I know what you're doing.
換言すると、最初３面側で温度変化が現われ、
続いて隣接する壁面である４面側および２面側で
温度変化が起こり、最後に４面側又は２面側に隣
接する壁面である１面側で温度変化が現われてい
るわけである。このシエル破断面が通過する際に
得られる測定データの各面に現われる時間遅れは
該破断面が巾方向および引抜方向へ伝播波及する
ことを表わしており、この波及状況は第４図ａ，
ｂ，ｃ，ｄならびにｅに示す。 In other words, a temperature change appears on the third side first,
Subsequently, a temperature change occurs on the 4th side and 2nd side, which are the adjacent wall surfaces, and finally a temperature change appears on the 1st side, which is the wall adjacent to the 4th side or the 2nd side. The time delay that appears on each side of the measurement data obtained when this shell fracture surface passes through indicates that the fracture surface propagates in the width direction and the pull-out direction, and this ripple situation is illustrated in Figure 4a,
Shown in b, c, d and e.
すなわち、第４図ａ，ｂ，ｃ，ｄならびにｅに
は鋳型壁面の展開図が示され、●印は各熱電対の
測温位置を示すと共に、符号Ｂはシエル破断面を
示す。第４図ａは３面側メニスカス近傍で焼付け
が発生した場合を示し、続いて第４図ｂはシエル
破断面が３面側の測温位置を通過したときに、３
面側温度がピークを示すことを示す。その後、シ
エル破断面が鋳型各壁面に伝播波及し、第４図ｃ
の通り、４面側温度がピークを示し、続いて第４
図ｄの通り２面側、第４図ｅの通り１面側の順で
温度ピークが現われる。このことから熱電対によ
つて検出温度が上昇してからその後、下降すると
いう温度変化パターンが連続して２つ以上の隣接
する熱電対で観測されたとき、ブレイクアウトの
発生を予知すれば、十分な対応操作時間をとるこ
とができ、誤りなくブレイクアウトの発生が予知
できる。つまり、第４図ｂに続くｃまたはｄのと
ころでブレイクアウトを予知すれば良いわけで、
この点から本発明方法では第４図ｃ又はｄでブレ
イクアウト発生を予知する。換言すれば、本発明
方法では鋳型壁面に埋設した複数個に熱電対によ
り、鋳型壁面温度を監視し、検出温度が平均温度
より一担上昇してから下降する温度変化パターン
が連続し、２個以上の隣接する熱電対で検出した
とき、ブレイクアウト発生の予知をするものであ
る。 That is, FIGS. 4a, b, c, d, and e show developed views of the mold wall surface, where ● marks indicate the temperature measurement positions of each thermocouple, and symbol B indicates the shell fracture surface. Figure 4a shows the case where seizure occurs near the meniscus on the third side, and Figure 4b shows the case where the shell fracture surface passes through the temperature measurement position on the third side.
This shows that the surface side temperature shows a peak. After that, the shell fracture surface propagates and spreads to each wall surface of the mold, as shown in Fig. 4c.
As shown, the temperature on the 4th side shows a peak, followed by the 4th side temperature.
Temperature peaks appear on the second side as shown in Figure d and on the first side as shown in Figure 4e. From this, if a temperature change pattern in which the temperature detected by a thermocouple rises and then falls is observed in two or more adjacent thermocouples in succession, the occurrence of a breakout can be predicted. Sufficient response time can be taken, and the occurrence of a breakout can be predicted without error. In other words, all you have to do is predict the breakout at point c or d following figure 4 b.
From this point of view, in the method of the present invention, the occurrence of breakout is predicted at c or d in FIG. In other words, in the method of the present invention, the mold wall temperature is monitored by a plurality of thermocouples embedded in the mold wall, and a temperature change pattern in which the detected temperature rises by one degree above the average temperature and then falls is continuous, and two thermocouples are embedded in the mold wall. When detected by the above-mentioned adjacent thermocouples, it is possible to predict the occurrence of a breakout.
また、上記の各過程から、第５図において鋳片
３のシエル破断面Ｂが鋳型の壁面に沿つて伝播波
及する速度を求めると、その鋳込速度（ν）の約
１／２の降下速度となる。また、第５図に示すよう
にブレイクアウトした鋳片の表面状況からシエル
破断面Ｂの伝播波及角度を調べると、水平レベル
に対しほぼ一定の角度（θ）で成長発達する過適
がみられる。このような現象はブルーム連鋳機の
みならず、スラブ連鋳機でも同様である（なお、
第５図において符号５はブレイクアウト発生点を
示す。）。 In addition, from each of the above processes, the speed at which the shell fracture surface B of the slab 3 propagates along the wall surface of the mold in Fig. 5 is determined, and the falling speed is approximately 1/2 of the casting speed (ν). becomes. In addition, when examining the propagation angle of the shell fracture surface B from the surface condition of the broken-out slab as shown in Figure 5, it is found that the propagation angle of the shell fracture surface B is excessive, growing at a nearly constant angle (θ) with respect to the horizontal level. . This phenomenon occurs not only in bloom continuous casters but also in slab continuous casters (note that
In FIG. 5, reference numeral 5 indicates the breakout occurrence point. ).
そこで以上の通り、シエル破断面の降下速度
（ν）、伝播波及角度（θ）、更に、ブレイクアウ
ト検知からその対応操作までの余裕時間（ｔ）等
から次の通りに熱電対配設位置を定めることがで
きる。 Therefore, as described above, the thermocouple placement position is determined as follows based on the descending speed of the shell fracture surface (ν), the propagation propagation angle (θ), and the margin time (t) from detection of breakout to countermeasure operation. can be determined.
まず、早朝にブレイクアウトを予知し、その対
応操作の時間的余裕を十分に得ようとする場合
は、鋳型上部に熱電対を埋め込むのが好ましい。
しかし、メニスカス近傍では熱電対の検出温度が
場面変動によつて大きく変動し、前述の温度上昇
および下降の変化パターンを検出することがむず
かしく、このため、できる限りこの範囲に熱電対
を埋設するのは好ましくない。そこで、熱電対は
鋳型下部に埋設するのが好ましく、その下限設定
は次の通り行なうことができる。すなわち、第６
図はl1×l2×l0の寸法の鋳型の壁面を展開して示
す展開図を示し、シエル破断面Ｂは第５図で示す
如く、水平レベルと角度θで伝播波及している。
なお、●印は、熱電対埋設部で、鋳型巾方向の熱
電対埋設間隔はｌとして示す。 First, if you want to predict a breakout early in the morning and have enough time to respond to it, it is preferable to embed a thermocouple in the upper part of the mold.
However, near the meniscus, the temperature detected by the thermocouple fluctuates greatly due to scene changes, making it difficult to detect the pattern of temperature rise and fall described above.For this reason, it is best to bury thermocouples in this range as much as possible. is not desirable. Therefore, it is preferable to embed the thermocouple in the lower part of the mold, and its lower limit can be set as follows. That is, the sixth
The figure shows a developed view showing the wall surface of a mold having dimensions l 1 ×l 2 ×l 0 , and the shell fracture surface B propagates and spreads at the horizontal level and at an angle θ, as shown in FIG.
Note that the ● mark is the thermocouple embedding part, and the thermocouple embedding interval in the mold width direction is indicated as l.
第６図から求めると、熱電対埋設位置は鋳型下
端からの距離を(L)とすると、(1)式で示される範囲
にするのがよい。 As determined from FIG. 6, the thermocouple embedding position should be within the range shown by equation (1), where (L) is the distance from the lower end of the mold.
Ｌ＞ｔ×ν／２ ……(1)
ただし、νは鋳込速度、ｔはブレイクアウト予
知後の余裕時間。 L>t×ν/2...(1) where ν is the casting speed and t is the margin time after predicting breakout.
また、熱電対はブレイクアウト検知の上からは
なるべく多く壁面に埋設するのが好ましい。しか
し、実用上は計測面、保守面等からなるべく少な
い個数で検出できるのが好ましい。したがつて、
熱電対埋設個数（Ｎ）は鋳型サイズ（巾、厚、長
さ）およびブレイクアウト予知後の余裕時間によ
つて増減し、熱電対配置高さを上記として次の(2)
式で示す鋳型巾方向の熱電対埋設間隔(l)にすれ
ば、必要最小限の熱電対個数（N^）が得られる。 Further, it is preferable to embed as many thermocouples as possible in the wall surface above the breakout detection. However, in practical terms, it is preferable to detect as few as possible from the viewpoint of measurement, maintenance, etc. Therefore,
The number of embedded thermocouples (N) will increase or decrease depending on the mold size (width, thickness, length) and the margin time after breakout prediction.
The minimum required number of thermocouples (N^) can be obtained by setting the thermocouple embedding interval (l) in the width direction of the mold as shown in the formula.
ｌ２×（Ｌ−ｔ×ν／２）／tanθ2l ……(2)
N^＝２×（l1＋l2）／ｌ ……(3)
ＮN^ ……(4)
ブレイクアウト発生過程では、第６図に示すシ
エル破断面Ｂがメニスカス近傍を基点として鋳型
下端に下降するので、鋳型下端にシエル破断部先
端が到達するまでの間に、前述の温度変化パター
ンが検出される時間に制限があることになり、こ
の隣接熱電対の検出時間間隔（Ｔ）はつぎの４式
で示される。 l2×(L-t×ν/2)/tanθ2l...(2) N^=2×(l 1 +l 2 )/l...(3) NN^...(4) In the breakout generation process, the Since the shell fracture surface B shown in Figure 6 descends to the lower end of the mold from the vicinity of the meniscus, there is a limit to the time during which the above-mentioned temperature change pattern can be detected until the tip of the shell fracture reaches the lower end of the mold. Therefore, the detection time interval (T) of the adjacent thermocouples is expressed by the following four equations.
Ｔltanθ÷ν／２ ……(4)
ただし、ｌは鋳型壁面巾方向の熱電対埋設間隔
距離、θはシエル破断面角度、νは鋳込速度であ
る。 Tltanθ÷ν/2 (4) where l is the distance between the thermocouples buried in the mold wall width direction, θ is the shell fracture surface angle, and ν is the casting speed.
つまり、一つの熱電対で前述の温度変化パター
ンが検出されても、上記時間Ｔ内に隣接する熱電
対で同様の温度変化パターンが検出されなけれ
ば、ブレイクアウト発生とはならないのであつ
て、この点からも誤判定をさけることができる。
又、時間Ｔ内に隣接しない熱電対（例えば、１つ
間をあけて２つ目の熱電対）で温度変化パターン
が検出されても、ブレイクアウト発生とはならな
い。 In other words, even if one thermocouple detects the temperature change pattern described above, unless a similar temperature change pattern is detected in an adjacent thermocouple within the above time T, a breakout will not occur. Misjudgments can also be avoided from the points.
Further, even if a temperature change pattern is detected in non-adjacent thermocouples (for example, a second thermocouple with a gap between them) within time T, a breakout does not occur.
要するに、本発明方法ではこの時間Ｔ内に連続
して２つ以上の隣接する熱電対において、温度変
化パターンが現われるという温度変化検出順序パ
ターンを検出し、これにもとづいてブレイクアウ
トの発生を予知するところに特徴がある。 In short, the method of the present invention detects a temperature change detection order pattern in which a temperature change pattern appears consecutively in two or more adjacent thermocouples within this time T, and based on this, predicts the occurrence of a breakout. The place has its characteristics.
実施例 次に、実施例について説明する。Example Next, examples will be described.
まず、第４図に示す通り、鋳型鋼板の４つの面
にそれぞれ１本ずつの熱電対を取付けた。これら
各熱電対は鋳型上端より200mm下のところで熱電
対先端部は鋳型鋼板内面から10mmのところに位置
させた。この連鋳装置において内断面積が300×
400mmで全長700mmの鋳型に0.86ｍ／分の速度で機
械構造用炭素鋼を鋳込んだ。この場合、タンデイ
ツシユの溶鋼温度はΔT＝36℃でブレイクアウト
が発生するまでの温度推移を求めたところ、第７
図の通りであつた。 First, as shown in FIG. 4, one thermocouple was attached to each of the four sides of a molded steel plate. Each of these thermocouples was positioned 200 mm below the upper end of the mold, and the tip of the thermocouple was positioned 10 mm from the inner surface of the mold steel plate. In this continuous casting equipment, the internal cross-sectional area is 300×
Carbon steel for mechanical structure was cast into a mold with a length of 400 mm and a total length of 700 mm at a speed of 0.86 m/min. In this case, the temperature of the molten steel in the tandate is ΔT = 36°C, and the temperature change until breakout occurs is calculated.
It was as shown in the picture.
第７図において、横軸の鋳込み時間の単位は１
分であり、各熱電対の測温値は一定の状態で推移
しているが、突如15〜20℃の温度上昇が表われ、
続いて100〜130℃の温度降下のパターン変化を生
じた。このパターン変化は例えば、上記の第３図
に示す場合と同様に、まず、３面側に設けた熱電
対により、ピークが検出され順次に、４面側、２
面側、１面側で検出され、１面側検出後若干の時
間差でブレイクアウトが発生した。 In Figure 7, the unit of casting time on the horizontal axis is 1
minutes, and the temperature values of each thermocouple remained constant, but suddenly a temperature rise of 15 to 20 degrees Celsius appeared.
Subsequently, a pattern change of temperature drop of 100-130℃ occurred. For example, this pattern change is similar to the case shown in FIG.
It was detected on the first side and the first side, and a breakout occurred with a slight time lag after the first side was detected.
そこで、この温度変化パターン検出時点のズレ
をまとめると、第８図に示すとおりであり、本発
明方法によれば少なくとも32秒前に確実にブレイ
クアウト予知がなされ、十分な余裕時間をもつて
いることがわかる。 Therefore, the deviation in the timing of detecting this temperature change pattern is summarized as shown in Fig. 8. According to the method of the present invention, a breakout prediction is reliably made at least 32 seconds in advance, and there is sufficient margin time. I understand that.
以上詳しく説明した通り、本発明方法は連続鋳
造鋳型内に温度計を埋め込み、その温度変化を検
出し、２つ以上の温度計で連続して温度変化が現
われる検出順序パターンをチエツクしてブレイク
アウトを予知するものであるから、拘束性ブレイ
クアウトの発生を確実に発生でき、未然に十分る
余裕をもつて防止することができる。 As explained in detail above, the method of the present invention embeds a thermometer in the continuous casting mold, detects the temperature change, and checks the detection order pattern in which temperature changes appear consecutively with two or more thermometers to achieve breakout. Since it is possible to predict the occurrence of a restrictive breakout, it is possible to reliably occur and prevent it with a sufficient margin.
第１図ａ，ｂ，ｃ，ｄ，ｅならびにｆは拘束性
ブレイクアウト発生過程の説明図、第２図は上記
過程でブレイクアウトが発生する際の第１図ａ〜
ｆのＡ部分の一つの熱電対での温度変化の推移を
示すグラフ、第３図はブレイクアウトの発生まで
の鋳型各面の温度変化を示すグラフ、第４図ａ，
ｂ，ｃ，ｄならびにｅはブレイクアウト発生まで
の推移を示す説明図、第５図はブレイクアウト発
生後の鋳型表面状況の説明図、第６図はシエル破
断面が鋳型壁面を伝播波及する状態を展開して示
す説明図、第７図は実際の鋳造時にブレイクアウ
トを予知するときの鋳型各面の温度変化を示すグ
ラフ、第８図は第４図の場合の各鋳型面の温度変
化ピーク発生時の時間的遅れを示すグラフであ
る。
符号、１……シエル、１ａ……シエルの弱い部
分、１ｂ……固着部、２……鋳型、３……鋳片、
４……乱れたオシレーシヨンマーク、５……ブレ
イクアウト発生点。
Figures 1 a, b, c, d, e, and f are explanatory diagrams of the process of generating a restrictive breakout, and Figure 2 is a diagram of Figures 1 a to 1 when breakout occurs in the above process.
A graph showing the transition of temperature change in one thermocouple in part A of f, Figure 3 is a graph showing the temperature change on each side of the mold until breakout occurs, Figure 4 a,
b, c, d, and e are explanatory diagrams showing the transition up to the breakout occurrence; Figure 5 is an explanatory diagram of the mold surface condition after the breakout occurrence; Figure 6 is the state in which the shell fracture surface propagates and spreads on the mold wall surface. Figure 7 is a graph showing the temperature changes on each mold surface when predicting breakout during actual casting, and Figure 8 is the peak temperature change on each mold surface in the case of Figure 4. It is a graph showing a time delay at the time of occurrence. Code, 1... shell, 1a... weak part of shell, 1b... fixed part, 2... mold, 3... slab,
4...Disturbed oscillation mark, 5...Breakout occurrence point.
Claims (1)
設し、これら熱電対中の一つの熱電対の検出温度
が検出平均温度より、一旦上昇してから下降した
ことを検出し、この一つの熱電対に隣接した他の
少なくとも一つの熱電対で、続いて上記検出温度
の温度変化パターンが検出されたときを、ブレイ
クアウト発生として予知することを特徴とする拘
束性ブレイクアウト予知方法。1 Multiple thermocouples are embedded in the mold wall of continuous casting equipment, and when the detected temperature of one of these thermocouples rises once and then falls from the detected average temperature, A method for predicting a constrained breakout, comprising predicting the occurrence of a breakout when a temperature change pattern of the detected temperature is subsequently detected in at least one other thermocouple adjacent to the pair.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3188382A JPS58148064A (en) | 1982-03-01 | 1982-03-01 | Predicting method for restrictive breakout |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3188382A JPS58148064A (en) | 1982-03-01 | 1982-03-01 | Predicting method for restrictive breakout |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58148064A JPS58148064A (en) | 1983-09-03 |
| JPS6347545B2 true JPS6347545B2 (en) | 1988-09-22 |
Family
ID=12343428
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3188382A Granted JPS58148064A (en) | 1982-03-01 | 1982-03-01 | Predicting method for restrictive breakout |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58148064A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011224582A (en) * | 2010-04-15 | 2011-11-10 | Nippon Steel Corp | Method for predicting breakout of continuous casting |
| JP2013052431A (en) * | 2011-09-06 | 2013-03-21 | Jfe Steel Corp | Method for measuring temperature in mold for continuous casting |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6061151A (en) * | 1983-09-14 | 1985-04-08 | Kawasaki Steel Corp | Foreseeing method of breakout |
| JPS60106653A (en) * | 1983-11-14 | 1985-06-12 | Nippon Steel Corp | Continuous casting method of steel |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5695461A (en) * | 1979-12-28 | 1981-08-01 | Nippon Steel Corp | Continuous casting method by mold provided with mold temperature measuring element |
-
1982
- 1982-03-01 JP JP3188382A patent/JPS58148064A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5695461A (en) * | 1979-12-28 | 1981-08-01 | Nippon Steel Corp | Continuous casting method by mold provided with mold temperature measuring element |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011224582A (en) * | 2010-04-15 | 2011-11-10 | Nippon Steel Corp | Method for predicting breakout of continuous casting |
| JP2013052431A (en) * | 2011-09-06 | 2013-03-21 | Jfe Steel Corp | Method for measuring temperature in mold for continuous casting |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58148064A (en) | 1983-09-03 |
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