JPS6319551A - Detection of sensor position abnormality in molten metal solidified state detector - Google Patents
Detection of sensor position abnormality in molten metal solidified state detectorInfo
- Publication number
- JPS6319551A JPS6319551A JP61165132A JP16513286A JPS6319551A JP S6319551 A JPS6319551 A JP S6319551A JP 61165132 A JP61165132 A JP 61165132A JP 16513286 A JP16513286 A JP 16513286A JP S6319551 A JPS6319551 A JP S6319551A
- Authority
- JP
- Japan
- Prior art keywords
- lift
- molten metal
- transmitted wave
- slab
- transmission time
- 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
- 239000002184 metal Substances 0.000 title claims abstract description 15
- 230000005856 abnormality Effects 0.000 title claims abstract description 14
- 238000001514 detection method Methods 0.000 title claims description 7
- 230000005540 biological transmission Effects 0.000 claims abstract description 23
- 238000007711 solidification Methods 0.000 claims description 21
- 230000008023 solidification Effects 0.000 claims description 21
- 238000000034 method Methods 0.000 claims description 16
- 238000005259 measurement Methods 0.000 abstract 3
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000005266 casting Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000005284 excitation Effects 0.000 description 3
- 238000002604 ultrasonography Methods 0.000 description 3
- 235000006693 Cassia laevigata Nutrition 0.000 description 2
- 241000522641 Senna Species 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- 238000009749 continuous casting Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 229940124513 senna glycoside Drugs 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 241000120020 Tela Species 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000001902 propagating effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Continuous Casting (AREA)
Abstract
Description
本発明は、溶湯金属凝固状態検出器のセンサ位置異常検
出方法に係り、特に、電磁的な方法で鋳片に透入させた
横波超音波が、鋳片内部の未凝固部を透過しないことを
利用して、その凝固の；ｉで５Ｌを検出する溶濶金腐凝
固状態検出器のセンサ位置異常検出方法に閃するもので
ある。The present invention relates to a sensor position abnormality detection method for a molten metal solidification state detector, and in particular, to detect that transverse ultrasonic waves transmitted through a slab by an electromagnetic method do not pass through unsolidified parts inside the slab. The present invention is inspired by a method for detecting an abnormality in the sensor position of a molten metal rot solidification state detector that detects 5L at i of solidification.
一般に、溶融金属の連続鋳造は、第５図に示すように、
タンディツシュ１０を通じて所定の断面形状を持った鋳
型１２内に溶湯１４を注入し、これを下方から鋳片１６
として連続的に引出寸ことによって行われている。鋳型
１２から引出された鋳片１６の内部は、未凝固溶湯を残
し、全体が凝固していく。このような３＋！！ＶＣ鋳造
において、鋳片１６の完全凝固点を正確に検出すること
は、鋳片内部の未凝固部が溶湯１４の圧力によって脹れ
て鋳片面が脹れる、いわゆるバルジング現象を防いだり
、冷ｉＪ］速度等のいわゆる鋳造条ｖトを最適ｔこ維持
するといった生産性、品質を向上させる情報となること
がよく知られている。
従来から、このような鋳片内部の凝固状態を検出する方
法として、超音波の横波の透過性を観察する方法が知ら
れている。この方法は、超音波の（黄波が液相中を伝）
番しないことを利用したものである。即ら、鋳片１こお
いて横波超音波が透過づる部分は内部が完全に凝固して
おり、横波超音波が透過しない部分は未凝固部が存在す
ると判断され乞
更に、上記方法と、高温あるいは粗面物体への超音波送
受信方法とを組合せた、鋳片における完全凝固位置検出
方法として、特開昭５２−１３０４２２が開示されてい
る。これは、電磁的な方法によって鋳片内部に）古人さ
せた横波超音波が透過するか否かによって、鋳片の凝固
状態を検出しようとするものである。
（発明が解決しようとする問題点１
しかしながら、電磁用３波の送受信において、鋳片にお
ける超音波の口Ｊ振強度、受信効率は、送信子あるいは
受信子と鋳片との距離（以下、リフトオフと称する）に
大きく依存している。従って、超音波の透過性の有無で
鋳片内部の凝固状態を検出する場合、リフトオフを適正
な一定値に保つ必要がある。即ら、リフトオフが過大で
あれば、励振強度と受信効率が下がるので、例え鋳片が
凝固していても透過波を見落す可１１ヒ性がある。逆に
、リフトオフが過少であれば、前述のような恐れ（よな
いものの、送受信子が鋳片に接触し、それらが破損する
恐れがある。
このため、電磁超音波を用いた方法においては、リフト
オフの過大、過少に注意する必要があるが、特開昭５２
−１３０４２２ではこの点に関して４瞭されておらず、
実用上支障があった。
本発明は、前記従来の問題点を解消するべくなれたもの
で、リフト・オフの異常を検出することができ、従って
、凝固状態を適確に検出することができる溶濶金腐凝固
状態検出器のセンナ位置異常検出方法を提供することを
目的とする。
【問題点を解決するため手段］
本発明は、電磁的な方法で鋳片に退入させた横波超音波
が、鋳片内部の未凝固部を透過しないことを利用して、
その凝固の状況を検出する溶ン易金腐凝固状態検出器の
センナ位置異常検出方法において、横波超音波の透過波
ピーク高さと透過時間を測定し、適正且つ一定のリフト
オフの下で予め定めておいた透過時間に対応する透過波
ピーク高さとの差異にυづいて、リフトオフの異常を検
出するようにして、前記目的を達成したものである。
［作用］
一般に１．超音波の伝播速度や透過波のピーク高さを支
配する減衰係数等は、その媒体の様々な物理的特性随に
より定まるが、鋳造中の鋳片に対してそ−れらを測定す
ることは困難である。
そこで、本発町者は、横波超音波の透過性を硯４、 Ｊ
る方式の鋳片の１疑固状態検出３において、その透過波
ピーク高さと透過時間に相関のあることを実験により見
いだした。その例を第２図及び第３図に示す。この関係
は、鋳片の種類、鋳造条件により異なるが、第２図は、
低炭素鋼、第３図は（眞低炭素鋼の相関関係を示したも
のであり、鋳片厚みはいずれも２３０！ＩＦｌである。
従って、透過波ピークｊ−さと透過時間の２つの足を、
ｌ１ｌｌ定し、その透過０１間に対応する第２図（低次
Ｍ鋼の場合）若しくは第３図（極低炭素鋼の場合）の透
過波ピーク高さと、測定した透過波ピーク高さとの差異
に基づいて、リフトオフの過大若しくは過少を検出する
ことができる。
第１図に、リフトオフを変化させた場合の透過波ピーク
高さと透過部間の関係の例を示す。対家とした鋳片は低
炭素鋼であり、鋳片厚みは２３０１鐙である。図中の実
線Ａは、適正なリフトオフの場合であり、実線Ｂ、実線
Ｃは、それぞれリフトオフを０．３１ｍ、０．６ｍｉだ
け適正値より更に大きくした場合である。第１図から、
リフトオフ過大による透過波ピーク高さの低下がわかる
。逆に、１Ｉ１１１定した透過波ピーク高さが、第１図
の実線８、実＊Ｃの値のように、適正なリフトオフ時の
値より小さくなれば、リフトオフ過大と直ちに判断てき
、適正な処首を施すことができる。リフトオフ過少の場
合には、これと逆の状態にある。
本発明は、上記のような知見に基づいてなされたもので
、？ｔＥｌａ的な方法で鋳片に退入させた横波超音波が
、鋳片内部の未凝固部を透過しないことを利用して、そ
の凝固の状況を検出する溶湯全屈凝固状態検出器のセン
サ位置異常を検出するに際して、横波超音波の透過波ピ
ーク高さと透過１１間を測定し、適正且つ一定のリフト
オフの下で予め定めておいた透過時間に対応する透過波
ピーク高さとの差異に基づいて、リフトオフの以上を検
出するようにしている。従って、リフトオフを容易に検
出することができ、鋳片の凝固状態を適確に検出するこ
とができる。
【実施例１
以下図面を参照して本発明の実施例を詳細に説明する。
本発明の対象となる鋳片の凝固状態検出器の暴本構成は
第４図に示す如くであり、鋳造中の鋳片１６の片側に電
磁的な超音波の送信子２０、他の側に電磁的な超音波の
受信子２２が配置されている。これらの送受信子２０，
２２が超音波を送受信するために、磁界励起回路２４か
ら電流が供給される。又、送信子２０には送信パルス発
生器２６からパルス電流が供給される。このパルス電流
の発生のタイミングは、タイミングコントロールユニッ
ト２８により制御され、パルス発生信号を゛送信パルス
発生ｚ ２６に送ると同時に信号処理回路３０にも送る
。受信子２２が受信した信号は、信号処理回路３０に入
り、平均化処理等の信号処理を受けた後、透過波のピー
ク値が計算される。
又、タイミングコントロールユニット２８からの信号と
受信信号とから、透過時間が計算されろ。
信号処理回路３０は、前出第１図に示したような関係か
ら、適正りつ一定のリフトオフの下で予め定めておいた
透過時間に対応する透過波ピーク高さと測定した透過波
ピーク高さとの差が、所定の値より６大きいか否かを判
断し、リフトオフの過大若しくは過少を検出する。検出
結果は警報器３２に出力され、操作者に知らされる。
本実施例においては、適正且つ一定のリフトオフの下で
予め定めておいた透過時間に対応する透過波ピーク高さ
と、測定した透過波ピーク高さと □の差が所定の
値よりも大きいか否かからリフトオフの過大又は過少を
検出するようにしていたので、リフ１〜オフの異常を容
易に検出することができる。
なお、リフトオフの異常を判定する方法はこれに゛ 限
定されず、例えば両者の比率からリフトオフの異常を検
出することも可能である。
（発明の効果］
以、ヒ説明した通り、本発明によれば、従来困難であっ
たリフトオフの過大や過少の検出が可能となる。従って
、リフトオフ過大による凝固、未凝固の判定の誤りや、
リフトオフ過少による超音波送受信子の破損を防ぐこと
ができる等の優れた効果を有する。Generally, continuous casting of molten metal is performed as shown in Figure 5.
Molten metal 14 is poured into a mold 12 having a predetermined cross-sectional shape through a tundish 10, and is poured into a slab 16 from below.
This is done by continuously increasing the drawer size. The inside of the slab 16 pulled out from the mold 12 solidifies, leaving unsolidified molten metal behind. 3+ like this! ! In VC casting, accurately detecting the complete solidification point of the slab 16 prevents the so-called bulging phenomenon, where the unsolidified part inside the slab swells due to the pressure of the molten metal 14 and the slab surface swells, and prevents the so-called bulging phenomenon, which occurs when the slab surface swells due to the pressure of the molten metal 14. It is well known that this information can be used to improve productivity and quality, such as maintaining the so-called casting strips at optimum speeds. Conventionally, as a method of detecting the solidification state inside a slab, a method of observing the transverse wave transmittance of ultrasonic waves has been known. This method uses ultrasonic (yellow waves propagating through the liquid phase)
This is to take advantage of the fact that there are no numbers. In other words, the parts of the slab 1 through which the transverse ultrasonic waves are transmitted are completely solidified, and the parts where the transverse ultrasonic waves are not transmitted are judged to have unsolidified parts. Alternatively, JP-A-52-130422 discloses a method for detecting the position of complete solidification in a cast slab, which combines a method for transmitting and receiving ultrasonic waves to a rough-surfaced object. This method attempts to detect the solidification state of a slab based on whether or not transverse ultrasonic waves generated inside the slab by an electromagnetic method are transmitted. (Problem to be Solved by the Invention 1) However, in the transmission and reception of three electromagnetic waves, the amplitude of the ultrasonic waves in the slab and the reception efficiency are determined by the distance between the transmitter or receiver and the slab (hereinafter referred to as lift-off). Therefore, when detecting the solidification state inside a slab based on the presence or absence of ultrasonic transmission, it is necessary to maintain the lift-off at an appropriate constant value.In other words, if the lift-off is excessive If the lift-off is too low, the excitation intensity and reception efficiency will decrease, so even if the slab is solidified, there is a possibility that the transmitted waves will be overlooked.On the other hand, if the lift-off is too low, the above-mentioned risks (such as Although this is not the case, there is a risk that the transmitter and receiver may come into contact with the slab and damage them.For this reason, in methods using electromagnetic ultrasonic waves, it is necessary to be careful not to lift off too much or too little.
-130422 is not clear on this point,
There was a practical problem. The present invention has been made to solve the above-mentioned conventional problems, and is capable of detecting lift-off abnormalities and, therefore, detecting the solidification state of molten metal rot, which can accurately detect the solidification state. An object of the present invention is to provide a method for detecting an abnormal position of a senna in a device. [Means for Solving the Problems] The present invention takes advantage of the fact that transverse ultrasonic waves that enter and leave the slab by an electromagnetic method do not pass through the unsolidified portion inside the slab.
In the senna position abnormality detection method of a meltable metal rot solidification state detector that detects the solidification state, the transmitted wave peak height and transmission time of transverse ultrasonic waves are measured, and the peak height and transmission time are determined in advance under an appropriate and constant lift-off. The above object is achieved by detecting lift-off abnormality based on the difference υ between the peak height of the transmitted wave corresponding to the transmitted time. [Effect] Generally 1. The propagation velocity of ultrasonic waves and the attenuation coefficient that governs the peak height of transmitted waves are determined by various physical properties of the medium, but it is difficult to measure them on slabs that are being cast. Have difficulty. Therefore, the present company decided to improve the transparency of transverse ultrasonic waves using inkstone 4, J
It was found through experiments that there is a correlation between the peak height of the transmitted wave and the transmission time in the quasi-solid state detection 3 of slabs using the method described above. Examples are shown in FIGS. 2 and 3. This relationship varies depending on the type of slab and casting conditions, but Fig. 2 shows that
Figure 3 shows the correlation between low carbon steel and low carbon steel.The thickness of each slab is 230!IFl. Therefore, the two legs of the transmitted wave peak j- and the transmission time are ,
The difference between the transmitted wave peak height in Figure 2 (in the case of low-order M steel) or Figure 3 (in the case of ultra-low carbon steel) and the measured transmitted wave peak height corresponding to the transmission 01 Based on this, it is possible to detect whether the lift-off is too high or too low. FIG. 1 shows an example of the relationship between the transmitted wave peak height and the transmitted portion when the lift-off is changed. The slab used as the opposite house is made of low carbon steel, and the thickness of the slab is 2301 stirrup. Solid line A in the figure shows the case of proper lift-off, and solid line B and solid line C show the case where the lift-off is made larger than the proper value by 0.31 m and 0.6 mi, respectively. From Figure 1,
It can be seen that the peak height of the transmitted wave decreases due to excessive lift-off. On the other hand, if the fixed transmitted wave peak height becomes smaller than the value at proper lift-off, as shown in the solid line 8 in Figure 1 and the value of actual *C, it is immediately determined that the lift-off is excessive, and proper treatment is necessary. You can apply the neck. In the case of insufficient lift-off, the situation is opposite to this. The present invention was made based on the above findings. The sensor position of the molten metal full bend solidification state detector that detects the solidification status by utilizing the fact that the transverse ultrasonic waves that enter and leave the slab using the tEla method do not pass through the unsolidified parts inside the slab. When detecting an abnormality, measure the peak height of the transmitted wave of the transverse ultrasound and the transmission 11, and based on the difference between the peak height of the transmitted wave corresponding to a predetermined transmission time under an appropriate and constant lift-off. , trying to detect more of lift-off. Therefore, lift-off can be easily detected, and the solidification state of the slab can be accurately detected. Embodiment 1 An embodiment of the present invention will be described in detail below with reference to the drawings. The basic configuration of the solidification state detector for a slab, which is the object of the present invention, is as shown in FIG. An electromagnetic ultrasound receiver 22 is arranged. These transceivers 20,
In order for 22 to transmit and receive ultrasound, a current is supplied from a magnetic field excitation circuit 24 . Further, a pulse current is supplied to the transmitter 20 from a transmission pulse generator 26. The timing of generation of this pulse current is controlled by the timing control unit 28, and the pulse generation signal is sent to the "transmission pulse generator z" 26 and also to the signal processing circuit 30 at the same time. The signal received by the receiver 22 enters the signal processing circuit 30, and after undergoing signal processing such as averaging processing, the peak value of the transmitted wave is calculated. Also, calculate the transmission time from the signal from the timing control unit 28 and the received signal. Based on the relationship shown in FIG. 1 above, the signal processing circuit 30 calculates the relationship between the transmitted wave peak height corresponding to a predetermined transmission time and the measured transmitted wave peak height under an appropriate and constant lift-off. It is determined whether the difference is 6 greater than a predetermined value, and excessive or insufficient lift-off is detected. The detection result is output to the alarm device 32 and notified to the operator. In this example, the difference between the transmitted wave peak height corresponding to a predetermined transmission time under an appropriate and constant lift-off and the measured transmitted wave peak height is larger than a predetermined value. Since excessive or insufficient lift-off is detected from the above, it is possible to easily detect abnormalities in lift-off from lift 1 to lift-off. Note that the method for determining lift-off abnormality is not limited to this, and it is also possible to detect lift-off abnormality from the ratio of both, for example. (Effects of the Invention) As explained below, according to the present invention, it is possible to detect excessive or insufficient lift-off, which has been difficult in the past.Therefore, it is possible to prevent errors in determining solidification or non-solidification due to excessive lift-off.
This has excellent effects such as being able to prevent damage to the ultrasonic transceiver due to insufficient lift-off.
第１図は、本発明の詳細な説明するための、リフトオフ
を変化させた場合の透過波ピーク高さと透過時間の関係
の例を示す線図、第２図及び第３図は、それぞれ低炭素
鋼、極低炭素鋼の場合における透過波ピーク高さと透過
時間の関係の例を示ず線図、第４図は、本発明が採用さ
れた溶湯金属凝固状態検出器の実施例の全体構成をホブ
、一部所面図を含むブロック線図、第５図は、本発明が
適用される連続鋳造機の概略構成を示す断面図である。
１６・・・鋳片、
２０・・・超音波送信子、
２２・・・超音波受信子、
２４・・・磁界励起回路、
２６・・・送信パルス発生器、
２８・・・タイミングコントロールユニット、３０・・
・信号処理回路、
３２・・・警報器。FIG. 1 is a diagram showing an example of the relationship between the transmitted wave peak height and the transmission time when the lift-off is changed, and FIGS. 2 and 3 are diagrams for explaining the present invention in detail, respectively. A diagram showing an example of the relationship between the transmitted wave peak height and the transmission time in the case of steel, ultra-low carbon steel, and FIG. A block diagram including a hob and a partial plan view, and FIG. 5 is a sectional view showing a schematic configuration of a continuous casting machine to which the present invention is applied. 16... Slab, 20... Ultrasonic transmitter, 22... Ultrasonic receiver, 24... Magnetic field excitation circuit, 26... Transmission pulse generator, 28... Timing control unit, 30...
・Signal processing circuit, 32...alarm device.
Claims (1)
鋳片内部の未凝固部を透過しないことを利用して、その
凝固の状況を検出する溶湯金属凝固状態検出器のセンサ
位置異常検出方法において、横波超音波の透過波ピーク
高さと透過時間を測定し、 適正且つ一定のリフトオフの下で予め定めておいた透過
時間に対応する透過波ピーク高さとの差異に基づいて、
リフトオフの異常を検出することを特徴とする溶湯金属
凝固状態検出器のセンサ位置異常検出方法。(1) Transverse ultrasonic waves transmitted through the slab using an electromagnetic method
In the sensor position abnormality detection method of a molten metal solidification state detector that detects the solidification status by utilizing the fact that it does not penetrate the unsolidified part inside the slab, the peak height and transmission time of the transmitted wave of transverse ultrasonic waves are measured. Based on the difference between the transmitted wave peak height corresponding to the predetermined transmission time under appropriate and constant lift-off,
A sensor position abnormality detection method for a molten metal solidification state detector characterized by detecting a lift-off abnormality.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61165132A JPH0610668B2 (en) | 1986-07-14 | 1986-07-14 | Sensor position abnormality detection method for molten metal solidification state detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61165132A JPH0610668B2 (en) | 1986-07-14 | 1986-07-14 | Sensor position abnormality detection method for molten metal solidification state detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6319551A true JPS6319551A (en) | 1988-01-27 |
| JPH0610668B2 JPH0610668B2 (en) | 1994-02-09 |
Family
ID=15806507
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61165132A Expired - Lifetime JPH0610668B2 (en) | 1986-07-14 | 1986-07-14 | Sensor position abnormality detection method for molten metal solidification state detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0610668B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102500747B (en) * | 2011-11-15 | 2014-04-02 | 田志恒 | Online detection system for solid-phase internal boundaries and solidification end positions of continuous casting blanks and method |
-
1986
- 1986-07-14 JP JP61165132A patent/JPH0610668B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0610668B2 (en) | 1994-02-09 |
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