JPH0548860B2 - - Google Patents
Info
- Publication number
- JPH0548860B2 JPH0548860B2 JP60291455A JP29145585A JPH0548860B2 JP H0548860 B2 JPH0548860 B2 JP H0548860B2 JP 60291455 A JP60291455 A JP 60291455A JP 29145585 A JP29145585 A JP 29145585A JP H0548860 B2 JPH0548860 B2 JP H0548860B2
- Authority
- JP
- Japan
- Prior art keywords
- slab
- ultrasonic
- transverse
- wave
- molten metal
- 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 - Lifetime
Links
- 239000002184 metal Substances 0.000 claims description 39
- 229910052751 metal Inorganic materials 0.000 claims description 39
- 238000000034 method Methods 0.000 claims description 28
- 238000007711 solidification Methods 0.000 claims description 17
- 230000008023 solidification Effects 0.000 claims description 17
- 238000002604 ultrasonography Methods 0.000 claims description 15
- 230000005540 biological transmission Effects 0.000 description 8
- 238000001514 detection method Methods 0.000 description 8
- 238000009749 continuous casting Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 230000003993 interaction Effects 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 239000000284 extract Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 238000005058 metal casting Methods 0.000 description 1
- 230000000644 propagated effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Continuous Casting (AREA)
Description
本発明は、鋳片の凝固状態検出方法に係り、特
に、連続鋳造鋳片の凝固状態を検出する際に用い
るのに好適な、電磁的な方法で鋳片に透入させた
横波超音波が、鋳片内部の残存溶融金属を透過し
ないことを利用して、鋳片の凝固状態を検出する
ようにした鋳片の凝固状態検出方法の改良に関す
る。
The present invention relates to a method for detecting the solidification state of a slab, and in particular, a transverse ultrasonic wave transmitted through a slab using an electromagnetic method, which is suitable for use in detecting the solidification state of a continuously cast slab. The present invention relates to an improvement in a method for detecting the solidification state of a slab, in which the solidification state of the slab is detected by utilizing the fact that the remaining molten metal inside the slab is not penetrated.
溶融金属の連続鋳造は、一般に、第８図に示す
ように、タンデツシユ１０から、所定の断面形状
を有する鋳型１２へ溶融金属１４を注入し、鋳型
１２の下方より、これを凝固金属１８と残存溶融
金属１９からなる鋳片１６として連続的に引出す
ことにより行われている。
前記鋳片１６は、鋳型１２より引出された直後
は、その内部に未凝固の残存溶融金属１９の厚い
層を有しているが、その後の冷却により、この残
存溶融金属１９は、外側より徐々に凝固して凝固
金属１８となり、やがては全体が凝固する。
このような溶融金属の連続鋳造に際して、連続
鋳造機の所定位置で鋳片１６の内部に残存溶融金
属１９が存在するか否かの鋳片凝固状態を常に監
視することは、内部の溶融金属が凝固層を破つて
外部へ漏出するブレイクアウト事故の防止や、鋳
片１６の引抜き速度と鋳片１６の冷却の関係を最
適にすることによつて、鋳片１６の品質や生産性
を向上させる上で極めて重要である。
前記のような鋳片１６の内部に残存溶融金属１
９が存在するか否かを検出する方法としては、従
来から横波超音波の透過性を観察する方法が知ら
れている。この方法は、横波が液体中を伝播しな
いことを利用するものである、即ち、鋳片におい
て横波超音波が通過する部分は、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、そ
の内部に残存溶融金属が存在すると判定できる。
又、この方法と、近年、超音波の高温あるいは
面の粗い物体への送受信方法として、その有効性
が広く知られるようになつた、電磁的な超音波の
送受信方法を組合せたものとして、特開昭52−
130422で開示された鋳片における完全凝固位置検
出方法がある。
この方法は、鋳片に横波超音波を電磁的な方法
で透入させ、この横波超音波の鋳片厚さ方向での
透過性から、鋳片における完全凝固位置を検出す
るものである。
Continuous casting of molten metal is generally carried out by injecting molten metal 14 from a tundish 10 into a mold 12 having a predetermined cross-sectional shape, as shown in FIG. This is done by continuously drawing out the molten metal 19 as a slab 16. Immediately after being pulled out from the mold 12, the slab 16 has a thick layer of unsolidified residual molten metal 19 inside it, but as it is cooled thereafter, this residual molten metal 19 is gradually removed from the outside. It solidifies into solidified metal 18, and eventually the whole solidifies. During such continuous casting of molten metal, it is important to constantly monitor the solidification state of the slab to determine whether there is residual molten metal 19 inside the slab 16 at a predetermined position of the continuous casting machine. The quality and productivity of the slab 16 are improved by preventing breakout accidents that occur when the solidified layer is broken and leaking to the outside, and by optimizing the relationship between the drawing speed of the slab 16 and the cooling of the slab 16. This is extremely important. There is residual molten metal 1 inside the slab 16 as described above.
As a method of detecting whether or not 9 exists, a method of observing transverse ultrasonic transmissivity is conventionally known. This method takes advantage of the fact that transverse waves do not propagate in liquid. In other words, the parts of the cast slab through which transverse ultrasound waves pass are completely solidified, and the parts where transverse ultrasound waves do not pass through are completely solidified. , it can be determined that there is residual molten metal inside. In addition, we have developed a special method that combines this method with an electromagnetic method for transmitting and receiving ultrasonic waves, which has recently become widely known for its effectiveness as a method for transmitting and receiving ultrasonic waves to objects with high temperatures or rough surfaces. 1977-
There is a method for detecting the completely solidified position in a slab disclosed in No. 130422. In this method, transverse ultrasonic waves are transmitted through the slab using an electromagnetic method, and the completely solidified position in the slab is detected from the permeability of the transverse ultrasonic waves in the thickness direction of the slab.
しかしながら、この特開昭52−130422で開示さ
れた方法には、次のような問題点があつた。即
ち、電磁的な超音波の送受信方法において、鋳片
における超音波の励振強度（送信の場合）、ある
いは超音波振動の受信効率（受信の場合）は、送
信子あるいは受信子の鋳片との距離（以下リフト
オフと称する）に大きく依存しており、リフトオ
フの変動の影響が、受信子における超音波の受信
強度にそのままあらわれてしまう。従つて、例え
ば、受信子に横波超音波の透過信号が得られない
場合でも、これが、鋳片の内部に残存溶融金属が
あるためか、あるいは、リフトオフの変動の影響
であるのか判断できず、鋳片の内部に残存溶融金
属があるとは断定できないことになる。又、送信
子、受信子、磁場発生装置、電気パルス発生器、
増幅器等からなる電磁的な超音波の送受信装置の
一部に故障又は破損が起こつた場合には、横波超
音波の透過信号の強度が弱まるか、あるいは、横
波超音波の透過信号が消失するといつた事態が発
生するが、これも、鋳片の内部に残存溶融金属が
あるための横波超音波の透過信号の低下あるいは
消失と全く区別がつかない。従つて、特開昭52−
130422に開示されている方法では、横波超音波の
透過信号が低下あるいは消失したからといつて、
鋳片の内部に残存溶融金属が存在するとは断定で
きないという問題点を有していた。
However, the method disclosed in JP-A-52-130422 has the following problems. In other words, in the electromagnetic method of transmitting and receiving ultrasonic waves, the excitation intensity of the ultrasonic waves in the slab (in the case of transmission) or the reception efficiency of the ultrasonic vibrations (in the case of reception) depends on the relationship between the transmitter or the receiver with the slab. It greatly depends on the distance (hereinafter referred to as lift-off), and the influence of lift-off fluctuations directly appears on the reception intensity of the ultrasonic wave at the receiver. Therefore, for example, even if a transverse ultrasound transmission signal is not obtained at the receiver, it cannot be determined whether this is due to residual molten metal inside the slab or the effect of lift-off fluctuations. This means that it cannot be determined that there is residual molten metal inside the slab. Also, transmitters, receivers, magnetic field generators, electric pulse generators,
If a part of the electromagnetic ultrasonic transmitting/receiving device consisting of an amplifier etc. malfunctions or is damaged, the intensity of the transverse ultrasonic transmission signal will weaken or the transverse ultrasonic transmission signal will disappear. However, this situation is completely indistinguishable from the reduction or disappearance of the transverse ultrasonic transmission signal due to residual molten metal inside the slab. Therefore, Japanese Unexamined Patent Application Publication No. 1973-
In the method disclosed in No. 130422, even if the transmission signal of transverse ultrasound waves has decreased or disappeared,
There was a problem in that it could not be determined that there was residual molten metal inside the slab.
本発明は、前記従来の問題点を解消するべくな
されたもので、リフトオフの変動や超音波の送受
信手段の故障あるいは損傷に拘わらず、安定確実
に鋳片の内部に残存溶融金属が存在するか否かの
鋳片の凝固状態を検出することができる鋳片の凝
固状態検出方法を提供することを目的とする。
The present invention was made to solve the above-mentioned conventional problems, and it is possible to stably and reliably ensure that residual molten metal exists inside the slab regardless of lift-off fluctuations or failures or damage to the ultrasonic transmitting/receiving means. It is an object of the present invention to provide a method for detecting the solidification state of a slab, which can detect the solidification state of a slab.
本発明は、電磁的な方法で鋳片に透入させた横
波超音波が、鋳片内部の残存溶融金属を透過しな
いことを利用して、鋳片の凝固状態を検出するよ
うにした鋳片の凝固状態検出方法において、縦波
超音波及び横波超音波を、電磁的な方法で同時に
鋳片に透入させ、鋳片を透過した縦波超音波及び
横波超音波を、電磁的な方法で受信し、横波超音
波の透過波の振幅と縦波超音波の透過波の振幅と
の比を求め、該振幅比に基づいて、鋳片内部の残
存溶融金属の存在を判定するようにして、前記目
的を達成したものである。
The present invention is a slab in which the solidification state of a slab is detected by utilizing the fact that transverse ultrasonic waves transmitted through the slab using an electromagnetic method do not pass through residual molten metal inside the slab. In this solidification state detection method, longitudinal and transverse ultrasonic waves are simultaneously transmitted through the slab using an electromagnetic method, and the longitudinal and transverse ultrasonic waves that have passed through the slab are detected using an electromagnetic method. receive the transverse ultrasonic wave, determine the ratio of the amplitude of the transmitted wave of the transverse ultrasonic wave to the amplitude of the transmitted wave of the longitudinal ultrasonic wave, and determine the presence of residual molten metal inside the slab based on the amplitude ratio, The above objective has been achieved.
第１図は、本発明の基本構成を示したものであ
る。
冷却によつて残存溶融金属１９の外壁は凝固金
属１８を形成しており、鋳片１６の片側に電磁的
な超音波の送信子２０、他方の側に電磁的な超音
波の受信子２２を配置している。前記超音波送信
子２０により超音波を鋳片１６に透入させるた
め、磁界発生用電源２４より調音波送信子２０へ
電流が供給されており、また、送信信号発生器２
６より、超音波送信子２０の送信コイル（図示省
略）に電気信号が供給されている。
又、超音波受信子２２により鋳片１６を透過し
た超音波信号を受信するため、磁界発生用電源２
８により超音波受信子２０へ磁界発生用電流が供
給されており、超音波受信子２２で受信され、電
気信号に変換された超音波信号は、増幅器３０に
より増幅されて、例えばオシロスコープ３２に表
示される。
ここにおいて、第２図に示すように、超音波が
透過する部分に残存溶融金属１９が存在しなけれ
ば、縦波、横波共に鋳片１６を透過し、オシロス
コープ３２には、第３図に示すような超音波信号
波形が得られる。一方、第４図のように、超音波
が透過する部分に残存溶融金属１９が存在すれ
ば、横波は液体中を伝播できないため、縦波のみ
が鋳片１６を透過し、第５図に示すような超音波
信号波形が得られる。
従つて、超音波受信子２０によつて受信された
超音波信号波形において、縦波の透過波の振幅
Alと横波の透過波の振幅Atの比At／Alをとり、
この比が例えば一定の閾値を下回る場合に、鋳片
１６の内部に残存溶融金属１９が存在すると判定
すれば、鋳片１６の凝固状態の検出が可能であ
る。
先にも述べたように、電磁的な超音波の送受信
方法においては、超音波送信子２０により鋳片１
６に透入される超音波の強度及び超音波受信子２
２による超音波受信効率は、各々超音波送信子２
０及び超音波受信子２２の鋳片１６に対するリフ
トオフに大きく依存するが、以上のような本発明
の方法によれば、例えば同一の送信子によつて、
縦波超音波及び横波超音波を同時に鋳片１６に透
入させ、例えば同一の超音波受信子２２によつ
て、縦波超音波及び横波超音波を受信するため、
受信信号における縦波、横波の振幅には、リフト
オフの変動の効果が同じだけ現われる。従つて、
リフトオフの変動の効果は、縦波の透過波の振幅
Alと横波の透過波の振幅Atとの比At／Alには全
く現われない。又、鋳片１６中の残存溶融金属１
９の有無に拘わらず、縦波の透過性はほぼ一定で
あることから、振幅比At／Alによつて、鋳片１
６における横波の透過性を正しく評価できる。更
に、縦波の透過波の振幅が一定の閥値を下回る場
合には、リフトオフ過大あるいは機器の故障とい
う判定を即座に下すことができる。
以上述べたように、本発明によれば、特開昭52
−130422の有する問題点は、一挙に解決される。
FIG. 1 shows the basic configuration of the present invention. By cooling, the outer wall of the remaining molten metal 19 forms a solidified metal 18, and an electromagnetic ultrasonic transmitter 20 is provided on one side of the slab 16, and an electromagnetic ultrasonic receiver 22 is provided on the other side. It is placed. In order to transmit ultrasonic waves into the slab 16 by the ultrasonic transmitter 20, a current is supplied from the magnetic field generation power source 24 to the harmonic wave transmitter 20, and the transmission signal generator 2
An electric signal is supplied from 6 to a transmitting coil (not shown) of the ultrasonic transmitter 20. In addition, in order to receive the ultrasonic signal transmitted through the slab 16 by the ultrasonic receiver 22, a magnetic field generation power source 2 is used.
A current for generating a magnetic field is supplied to the ultrasonic receiver 20 by 8, and the ultrasonic signal received by the ultrasonic receiver 22 and converted into an electric signal is amplified by an amplifier 30 and displayed on, for example, an oscilloscope 32. be done. Here, as shown in FIG. 2, if there is no residual molten metal 19 in the area through which the ultrasonic wave passes, both the longitudinal wave and the transverse wave will pass through the slab 16, and the oscilloscope 32 will see the wave as shown in FIG. An ultrasonic signal waveform like this can be obtained. On the other hand, as shown in FIG. 4, if residual molten metal 19 exists in the area through which the ultrasonic waves are transmitted, transverse waves cannot propagate in the liquid, and only longitudinal waves will pass through the slab 16, as shown in FIG. An ultrasonic signal waveform like this can be obtained. Therefore, in the ultrasound signal waveform received by the ultrasound receiver 20, the amplitude of the transmitted longitudinal wave
Take the ratio At/Al of the amplitude At of the transmitted wave of Al and the transverse wave,
If this ratio is lower than a certain threshold, for example, and it is determined that residual molten metal 19 exists inside the slab 16, the solidification state of the slab 16 can be detected. As mentioned earlier, in the electromagnetic ultrasonic transmission/reception method, the ultrasonic transmitter 20 sends the slab 1
Intensity of ultrasound transmitted to 6 and ultrasound receiver 2
2, the ultrasonic reception efficiency by ultrasonic transmitter 2 is
0 and the lift-off of the ultrasonic receiver 22 relative to the slab 16, but according to the method of the present invention as described above, for example, by the same transmitter,
In order to simultaneously transmit longitudinal and transverse ultrasonic waves into the slab 16 and receive the longitudinal and transverse ultrasonic waves by, for example, the same ultrasonic receiver 22,
The amplitudes of longitudinal and transverse waves in the received signal are equally affected by lift-off fluctuations. Therefore,
The effect of lift-off variation is the amplitude of the transmitted longitudinal wave.
It does not appear at all in the ratio At/Al between Al and the amplitude At of the transmitted transverse wave. In addition, the remaining molten metal 1 in the slab 16
Since the longitudinal wave permeability is almost constant regardless of the presence or absence of 9, the amplitude ratio At/Al
Transverse wave permeability in 6 can be correctly evaluated. Furthermore, if the amplitude of the transmitted longitudinal wave is below a certain threshold, it can be immediately determined that lift-off is excessive or the equipment is malfunctioning. As described above, according to the present invention,
-130422's problems are solved all at once.
以下、図面を参照して、本発明に係る鋳片の凝
固状態検出方法が採用された連続鋳造鋳片の凝固
状態検出装置の実施例を詳細に説明する。
本実施例は、第６図に示す如く構成されてお
り、第１図と同様に、電磁的な超音波送信子２０
を鋳片１６の片側に、電磁的な超音波受信子２２
を、鋳片１６の他方の側に配置している。
前記超音波送信子２０及び超音波受信子２２
は、いずれも、１つの送信子又は受信子によつ
て、縦波と横波を同時に送信又は受信可能なもの
であり、第７図に詳細に示す如く構成されてい
る。図において、１０２及び１１２は、磁界発生
用コイルであり、それぞれ前出第１図と同様の磁
界発生用電源２４，２８に接続されている。又、
１０３及び１１３は、磁界発生用の鉄心である。
更に、１０５は送信用コイルで、送信信号発生器
２６に接続されている。ここで、例えば磁界発生
用電源２４より磁界発生用コイル１０２に直流電
流を通電せしめると、破線Ａで表わされるような
磁界が発生する。同時に送信用コイル１０５に送
信信号発生器２６との組合せによつて、例えば
RLC共振の減衰振動によつて発生させたパルス
電流を流すと、誘導電流Ｂが、凝固金属１８の表
面に図のように発生し、この誘導電流Ｂと磁界Ａ
の相互作用により、フレミングの法則に従つて、
凝固金属１８の表面にローレンツ力が発生する。
この時、送信用コイル１０５のうち、ａで示され
る部分からは、凝固金属１８の表面に誘導電流Ｂ
のうち、ａで示される誘導電流が誘導されるが、
この誘導電流Baと磁界Ａの相互作用によつて、
凝固金属表面には、矢印Caに示されるローレン
ツ力が発生する。このローレンツ力は、矢印Ｄの
方向に進行する縦波を発生させる。又、送信用コ
イル１０５のうち、ｂで示される部分からは、凝
固金属１８の表面に、誘導電流Ｂのうち、ｂで示
される誘導電流が誘導されるが、この誘導電流
Bbと磁界Ａの相互作用によつて、凝固金属１８
の表面には、矢印Cbで示されるローレンツ力が
発生する。このローレンツ力は、同じく矢印Ｄの
方向へ進行する横波を発生させる。このようにし
て、一つの超音波送信子２０により、同時に縦波
及び横波を電磁的に鋳片１６に透入させることが
できる。
さて、矢印Ｄの方向に伝播して鋳片１６の反対
側の表面に達した縦波及び横波は、それぞれ矢印
Ea，Ebで示される運動力を持つており、これと
超音波受信子２２による磁界（破線）Ｆとの相互
作用によつて、誘導電流Ga，Gbが生じ、機械的
な振動が電気信号に変換されて、受信コイル１１
５により検出される。このようにして、一つの超
音波受信子２２により、縦波及び横波を電磁的に
受信することができる。
前記超音波受信子２２によつて受信され、電気
信号に変換された超音波信号は、第１図と同様の
増幅器３０に入力される。増幅器３０は、入力さ
れた超音波信号を増幅した後、二つのチヤンネル
から、これをゲート回路３４Ａ，３４Ｂへ出力す
る。ゲート回路３４Ａ，３４Ｂに出力される電気
信号は全く同等である。
ゲート回路３４Ａは、入力された信号から縦波
による信号を抽出し、ピーク値検出回路３６Ａへ
出力する。ピーク値検出回路３６Ａは、入力され
た縦波による信号の振幅Alを検出して、これを
演算処理器３８へ出力する。又、他方のゲート回
路３４Ｂは、入力された信号から横波による信号
を取出して、ピーク値検出回路３６Ｂへ出力す
る。ピーク値検出回路３６Ｂは、入力された横波
による信号の振幅Atを検出して、これを前記演
算処理器３８へ出力する。
演算処理器３８は、入力された振幅Al，Atの
値から、横波の超音波の振幅と縦波の超音波の振
幅の比（At／Al）を計算し、この値と閥値とを
比較して、鋳片１６の中の残存溶融金属１９の有
無を判定する他、縦波の超音波の振幅Alが一定
のレベルよりも低い場合には、ブザー等の警報器
４０へ警報信号を出力する。
なお、前記実施例においては、電磁的に超音波
を送信し、受信するための磁界として、直流電流
による磁界を用いていたが、永久磁石による磁界
又はコイルにパルス状の大電流を流して誘起され
るパルス状磁界であつてもよい。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a continuous casting slab solidification state detection apparatus employing a slab solidification state detection method according to the present invention will be described in detail with reference to the drawings. This embodiment is constructed as shown in FIG. 6, and similarly to FIG. 1, an electromagnetic ultrasonic transmitter 20
An electromagnetic ultrasonic receiver 22 is placed on one side of the slab 16.
are arranged on the other side of the slab 16. The ultrasonic transmitter 20 and the ultrasonic receiver 22
Both are capable of transmitting or receiving longitudinal waves and transverse waves simultaneously by one transmitter or receiver, and are constructed as shown in detail in FIG. 7. In the figure, reference numerals 102 and 112 are magnetic field generating coils, which are connected to magnetic field generating power supplies 24 and 28, respectively, similar to those shown in FIG. 1 above. or,
103 and 113 are iron cores for generating magnetic fields.
Further, 105 is a transmitting coil, which is connected to the transmitting signal generator 26. Here, for example, when a direct current is applied to the magnetic field generating coil 102 from the magnetic field generating power supply 24, a magnetic field as shown by the broken line A is generated. At the same time, by combining the transmitting coil 105 with the transmitting signal generator 26, for example,
When a pulse current generated by the damped vibration of RLC resonance is passed, an induced current B is generated on the surface of the solidified metal 18 as shown in the figure, and this induced current B and magnetic field A
According to Fleming's law, due to the interaction of
A Lorentz force is generated on the surface of the solidified metal 18.
At this time, an induced current B is generated on the surface of the solidified metal 18 from a portion of the transmitting coil 105 indicated by a.
Of these, the induced current indicated by a is induced,
Due to the interaction between this induced current Ba and the magnetic field A,
Lorentz force, indicated by arrow Ca, is generated on the solidified metal surface. This Lorentz force generates a longitudinal wave traveling in the direction of arrow D. Further, from the portion of the transmitting coil 105 indicated by b, an induced current indicated by b of the induced current B is induced on the surface of the solidified metal 18.
Due to the interaction between Bb and magnetic field A, solidified metal 18
Lorentz force, indicated by arrow Cb, is generated on the surface of . This Lorentz force also generates a transverse wave traveling in the direction of arrow D. In this way, one ultrasonic transmitter 20 can transmit longitudinal waves and transverse waves electromagnetically into the slab 16 at the same time. Now, the longitudinal waves and transverse waves that propagated in the direction of arrow D and reached the surface on the opposite side of the slab 16 are
It has kinetic forces shown as Ea and Eb, and the interaction between this and the magnetic field (broken line) F from the ultrasonic receiver 22 generates induced currents Ga and Gb, and mechanical vibrations are converted into electrical signals. After being converted, the receiving coil 11
Detected by 5. In this way, one ultrasonic receiver 22 can electromagnetically receive longitudinal waves and transverse waves. The ultrasound signal received by the ultrasound receiver 22 and converted into an electrical signal is input to an amplifier 30 similar to that shown in FIG. After amplifying the input ultrasonic signal, the amplifier 30 outputs it to gate circuits 34A and 34B from two channels. The electrical signals output to the gate circuits 34A and 34B are completely equivalent. The gate circuit 34A extracts a longitudinal wave signal from the input signal and outputs it to the peak value detection circuit 36A. The peak value detection circuit 36A detects the amplitude Al of the input longitudinal wave signal and outputs it to the arithmetic processor 38. Further, the other gate circuit 34B extracts a transverse wave signal from the input signal and outputs it to the peak value detection circuit 36B. The peak value detection circuit 36B detects the amplitude At of the input transverse wave signal and outputs it to the arithmetic processor 38. The arithmetic processor 38 calculates the ratio of the amplitude of the transverse ultrasonic wave to the amplitude of the longitudinal ultrasonic wave (At/Al) from the input values of the amplitudes Al and At, and compares this value with the threshold value. In addition to determining the presence or absence of residual molten metal 19 in the slab 16, if the amplitude Al of the longitudinal ultrasonic wave is lower than a certain level, an alarm signal is output to an alarm device 40 such as a buzzer. do. In the above embodiment, a magnetic field generated by a direct current was used as the magnetic field for electromagnetically transmitting and receiving ultrasonic waves. The magnetic field may be a pulsed magnetic field.
以上説明したとおり、本発明によれば、リフト
オフの変動や超音波送信手段の故障あるいは損傷
に拘わらず、鋳片の内部に残存溶融金属が存在す
るか否かを、安定かつ確実に検出することができ
る。従つて、金属の連続鋳造におけるブレイクア
ウト事故の防止や、鋳片の引抜き速度と冷却条件
を最適とするための制御において、極めて有効に
利用できるという優れた効果を有する。
As explained above, according to the present invention, it is possible to stably and reliably detect whether or not residual molten metal exists inside a slab, regardless of lift-off fluctuations or failure or damage to the ultrasonic transmitting means. I can do it. Therefore, it has an excellent effect that it can be used extremely effectively in preventing breakout accidents in continuous metal casting and in controlling to optimize the drawing speed and cooling conditions of slabs.
第１図は、本発明に係る鋳片の凝固状態検出方
法を実施するための装置の基本的な構成を示す断
面図、第２図は、本発明の原理を説明するため
の、鋳片内の残存溶融金属と電磁的な超音波の送
受信手段との相対的な位置関係の例を示す断面
図、第３図は、第２図の状態における超音波の受
信信号波形の例を示す線図、第４図は、鋳片内の
残存溶融金属と超音波送受信手段との相対的な位
置関係の他の例を示す断面図、第５図は、第４図
の状態における超音波の受信信号波形の例を示す
線図、第６図は、本発明が採用された連続鋳造鋳
片の凝固状態検出装置の実施例の構成を示す、一
部ブロツク線図を含む断面図、第７図は、前記実
施例で用いられている超音波送信子及び受信子の
構成及び作用を示す断面図、第８図は、金属鋳片
の連続鋳造機の構成の例を示す断面図である。
１６……鋳片、１８……凝固金属、１９……残
存溶融金属、２０……超音波送信子、２２……超
音波受信子、At……横波超音波の透過波の振幅、
Al……縦波超音波の透過波の振幅。
FIG. 1 is a sectional view showing the basic configuration of an apparatus for carrying out the method for detecting the solidification state of a slab according to the present invention, and FIG. 3 is a cross-sectional view showing an example of the relative positional relationship between the remaining molten metal and the electromagnetic ultrasonic transmitting/receiving means, and FIG. 3 is a line diagram showing an example of the received ultrasonic signal waveform in the state shown in FIG. , FIG. 4 is a cross-sectional view showing another example of the relative positional relationship between the remaining molten metal in the slab and the ultrasonic transmitting/receiving means, and FIG. 5 is an ultrasonic reception signal in the state shown in FIG. 4. FIG. 6 is a diagram showing an example of a waveform, and FIG. 6 is a sectional view including a partial block diagram, showing the configuration of an embodiment of a solidification state detection device for continuously cast slab to which the present invention is adopted. FIG. 8 is a cross-sectional view showing the structure and operation of the ultrasonic transmitter and receiver used in the above embodiment. FIG. 8 is a cross-sectional view showing an example of the structure of a continuous casting machine for metal slabs. 16... Slab, 18... Solidified metal, 19... Residual molten metal, 20... Ultrasonic transmitter, 22... Ultrasonic receiver, At... Amplitude of transmitted wave of transverse ultrasonic wave,
Al...Amplitude of transmitted wave of longitudinal ultrasound.
Claims (1)
が、鋳片内部の残存溶融金属を透過しないことを
利用して、鋳片の凝固状態を検出するようにした
鋳片の凝固状態検出方法において、 縦波超音波及び横波超音波を、電磁的な方法で
同時に鋳片に透入させ、 鋳片を透過した縦波超音波及び横波超音波を、
電磁的な方法で受信し、 横波超音波の透過波の振幅と縦波超音波の透過
波の振幅との比を求め、 該振幅比に基づいて、鋳片内部の残存溶融金属
の存在を判定することを特徴とする鋳片の凝固状
態検出方法。[Claims] 1. The solidification state of the slab is detected by utilizing the fact that transverse ultrasonic waves transmitted through the slab using an electromagnetic method do not pass through the remaining molten metal inside the slab. In the method for detecting the solidification state of a slab, longitudinal ultrasound waves and transverse ultrasound waves are simultaneously transmitted through the slab using an electromagnetic method, and the longitudinal ultrasound waves and transverse ultrasound waves that have passed through the slab are detected.
Receive it by electromagnetic method, find the ratio of the amplitude of the transmitted wave of transverse ultrasonic wave and the amplitude of the transmitted wave of longitudinal ultrasonic wave, and determine the presence of residual molten metal inside the slab based on the amplitude ratio. A method for detecting the solidification state of a cast slab.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60291455A JPS62148850A (en) | 1985-12-24 | 1985-12-24 | Solidification state detecting method for billet |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60291455A JPS62148850A (en) | 1985-12-24 | 1985-12-24 | Solidification state detecting method for billet |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62148850A JPS62148850A (en) | 1987-07-02 |
| JPH0548860B2 true JPH0548860B2 (en) | 1993-07-22 |
Family
ID=17769087
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60291455A Granted JPS62148850A (en) | 1985-12-24 | 1985-12-24 | Solidification state detecting method for billet |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62148850A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020039850A1 (en) * | 2018-08-22 | 2020-02-27 | 国立大学法人東北大学 | Method and device for evaluating bonding interface |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10045250A1 (en) * | 2000-09-13 | 2002-03-21 | Sms Demag Ag | Process for determining the position of the final solidification in a casting strand during continuous casting of steel comprises measuring the strand pulling force and/or holding force of supporting segments |
| WO2002090971A1 (en) | 2001-04-25 | 2002-11-14 | Nkk Corporation | Method of producing continuously cast pieces of steel |
| WO2005051569A1 (en) * | 2003-11-27 | 2005-06-09 | Jfe Steel Corporation | Method for detecting solidification completion position of continuous casting cast piece, detector, and method for producing continuous casting cast piece |
| JP5236385B2 (en) * | 2008-08-04 | 2013-07-17 | 本田技研工業株式会社 | Melting zone interface position detection method and apparatus |
| JP6358035B2 (en) * | 2014-10-14 | 2018-07-18 | 新日鐵住金株式会社 | Measuring device, measuring method, program, and storage medium |
-
1985
- 1985-12-24 JP JP60291455A patent/JPS62148850A/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020039850A1 (en) * | 2018-08-22 | 2020-02-27 | 国立大学法人東北大学 | Method and device for evaluating bonding interface |
| US11898990B2 (en) | 2018-08-22 | 2024-02-13 | Shimane University | Bonding interface evaluation method and bonding interface evaluation device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62148850A (en) | 1987-07-02 |
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