JPH0235622B2 - RENZOKUCHUZONIOKERUBUREEKUAUTOYOCHIHOHO - Google Patents
RENZOKUCHUZONIOKERUBUREEKUAUTOYOCHIHOHOInfo
- Publication number
- JPH0235622B2 JPH0235622B2 JP17524884A JP17524884A JPH0235622B2 JP H0235622 B2 JPH0235622 B2 JP H0235622B2 JP 17524884 A JP17524884 A JP 17524884A JP 17524884 A JP17524884 A JP 17524884A JP H0235622 B2 JPH0235622 B2 JP H0235622B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- breakout
- oil pressure
- difference
- slab
- 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
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
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
Description
〔発明の技術分野〕
この発明は、鋼の連続鋳造において、ブレーク
アウトの発生を未然に検知することができる、連
続鋳造におけるブレークアウト予知方法に関する
ものである。
〔従来技術とその問題点〕
連続鋳造の操業において、生産性の向上のため
に、鋳造速度の高速化が要求されている。しかる
に、高速で連続鋳造を行なうと、鋳型直下の未凝
固鋳片にブレークアウトが生じやすくなるため、
このブレークアウトの発生が鋳造速度の高速化の
大きな技術的障害となつている。
ブレークアウトには、一般に、鋳型内のシエル
の成長遅れに起因するものと、未凝固鋳片と鋳型
間の摩擦力が未凝固鋳片の高温強度以上となるこ
とに起因するものとがある。
連続鋳造では、周知の如く、鋳型内の溶鋼の湯
面上に鋳型パウダーが添加されている。このパウ
ダーは、溶融して鋳型と未凝固鋳片間に均一に流
入し、これによつて未凝固鋳片の下方への引抜き
が容易となるような潤滑作用を果たしているもの
である。
しかしながら、溶融したパウダーの鋳型と未凝
固鋳片間への流入が不均一となつたり、その流入
量が減少した場合には、鋳型と未凝固鋳片間の摩
擦力が上昇するので、その摩擦力が未凝固鋳片の
高温強度以上となることによるブレークアウトが
発生する。
そこで、この種のブレークアウトの防止のため
に、種々の対策がとられているが、未だ充分な効
果が得られていないのが現状である。
〔発明の目的〕
この発明は、上述の現状に鑑み、鋳型から引抜
かれる未凝固鋳片のブレークアウトを予知して、
ブレークアウトの発生を未然に防ぐことを可能と
する、連続鋳造におけるブレークアウト予知方法
を提供することを目的とする。
〔発明の概要〕
この発明の連続鋳造におけるブレークアウト予
知方法は、鋳型を振動させるための油圧シリンダ
ーの、押し側と押し戻し側との間の油圧の差を連
続的に測定し、一方、前記油圧の差の未凝固鋳片
にブレークアウトの生ずることのない定常値を予
め設定し、前記測定された油圧の差が前記定常値
の120〜130％を超えたときを、前記鋳型から引抜
かれる未凝固鋳片にブレークアウトが生ずる危険
状態のときとして、前記鋳型から引抜かれる未凝
固鋳片のブレークアウトの発生を予知することに
特徴を有する。
〔発明の構成〕
本発明者等は、上述した未凝固鋳片と鋳型間の
摩擦力が、未凝固鋳片の高温強度以上となつて発
生するブレークアウトを防止すべく、鋭意研究を
重ねた。その結果、油圧力によつて振動される鋳
型では、鋳型に振動を与えるための油圧シリンダ
ーの押し側と押し戻し側との間の油圧の差が、鋳
型と未凝固鋳片間の摩擦力が上昇すると、鋳型の
振幅および振動数を一定に保とうとするために、
大きくなること、従つて、この油圧の差を測定す
れば、その油圧の差の変化から、鋳型と未凝固鋳
片間の潤滑状態が判り、ブレークアウトの発生を
予知することができることを見い出した。この発
明は、上記知見によりなされたものである。
次に、この発明を図面に基づいて説明する。
第１図は、この発明の一実施態様を示す説明図
である。第１図において、１は水冷鋳型２の水
箱、３は鋳型２の鋳型フレーム、４は鋳型２を支
持するための鋳型支持フレーム、５は鋳型２を振
動するためのオシレーシヨンフレームである。オ
シレーシヨンフレーム５の一端には、第２図に示
すように、往復動油圧シリンダー６が取付けら
れ、この油圧シリンダー６の押し側６ａと押し戻
し側６ｂに接続された作動油が通る配管７ａ，７
ｂには、押し側６ａ、押し戻し側６ｂの油圧を測
定するための油圧計８ａ，８ｂが設けられてい
る。振動する鋳型２内に注入された溶鋼９は、鋳
型２内で凝固シエル１０を生成して未凝固鋳片１
１となり、鋳片支持ロール１２に支持されなが
ら、鋳型２から引抜かれる。
この発明においては、油圧シリンダー６の押し
側６ａと押し戻し側６ｂとの間の油圧の差の変化
を監視し、これによつて鋳型２と凝固シエル１０
との間の潤滑状態を知り、未凝固鋳片１１のブレ
ークアウトを予知するものである。
すなわち、鋳型２と鋳型２内の凝固シエル１０
との間の潤滑状態が良好で、未凝固鋳片１１が鋳
型２から正常に引抜かれている場合には、油圧計
８ａで測定される押し側６ａの油圧と、８ｂで測
定される押し戻し側６ｂの油圧との差△Ｐは、ほ
とんど変化しない。一方、鋳型２と凝固シエル１
０との間の潤滑状態が悪化して、鋳型２と未凝固
鋳片１１との間の摩擦力が上昇すると、前記油圧
の差△Ｐは増大する。この油圧の差△Ｐの定常値
△P0に対する変動量△（△Ｐ）＝△Ｐ−△P0は、
鋳型２と未凝固鋳片１１との間の摩擦力の大小に
よつて決まるから、この変動量△（△Ｐ）から鋳
型２と凝固シエル１０との間の潤滑状態を知るこ
とができ、未凝固鋳片１１のブレークアウトを未
然に検出することができる。
摩擦力が未凝固鋳片１１にブレークアウトの危
険を生ずるときの、油圧シリンダー６の前記油圧
の差△Ｐは、連続鋳造機の機種および鋳造条件に
よつても異なるが、実操業上の経験によれば、定
常値△P0の120〜130％に選択すれば良いことが
確認されている。従つて、油圧の差△Ｐの上限と
して、定常値△P0の120〜130％の圧力を設定し
ておけば、未凝固鋳片１１がブレークアウトを生
ずる危険状態だけを、選択的に取り出すことがで
きる。
上記により、油圧シリンダー６の押し側と押し
戻し側との間の油圧の差の変化から、未凝固鋳片
１１のブレークアウトの発生が予知されたときに
は、この予知からブレークアウトの発生までに、
１〜２分間程度の時間的余裕があるので、この間
に、鋳型２内への溶鋼９の注入停止、注入速度の
低下、パウダーの変更などの処置を採れば、ブレ
ークアウトの発生を未然に防止することができ
る。
〔発明の実施例〕
次に、この発明を実施例により説明する。
第１表に示す成分組成の厚さ250mm、幅1750mm
の厚板用40キロ級スラブを、10.5ｍＲの湾曲型連
続鋳造機により鋳造し、その間の油圧シリンダー
の、押し側と押し戻し側との間の油圧の差圧△Ｐ
を連続的に測定した。
[Technical Field of the Invention] The present invention relates to a breakout prediction method in continuous casting that can detect the occurrence of a breakout in advance in continuous casting of steel. [Prior art and its problems] In continuous casting operations, higher casting speeds are required in order to improve productivity. However, when continuous casting is performed at high speed, breakout tends to occur in the unsolidified slab directly under the mold.
The occurrence of this breakout is a major technical obstacle to increasing the casting speed. Generally, breakouts are caused by delayed growth of the shell within the mold, and breakouts are caused by the frictional force between the unsolidified slab and the mold exceeding the high-temperature strength of the unsolidified slab. In continuous casting, as is well known, mold powder is added to the surface of molten steel in a mold. This powder melts and flows uniformly between the mold and the unsolidified slab, thereby providing a lubricating effect that facilitates the downward drawing of the unsolidified slab. However, if the flow of molten powder between the mold and the unsolidified slab becomes uneven or the amount of the inflow decreases, the frictional force between the mold and the unsolidified slab increases. Breakout occurs when the force exceeds the high temperature strength of the unsolidified slab. Therefore, various measures have been taken to prevent this type of breakout, but the current situation is that sufficient effects have not yet been obtained. [Object of the Invention] In view of the above-mentioned current situation, the present invention has been made to predict the breakout of unsolidified slabs pulled out from the mold,
It is an object of the present invention to provide a method for predicting breakout in continuous casting, which makes it possible to prevent the occurrence of breakout. [Summary of the Invention] The breakout prediction method in continuous casting of the present invention continuously measures the difference in oil pressure between the push side and the push back side of a hydraulic cylinder for vibrating a mold, and A steady value that does not cause a breakout in the unsolidified slab is set in advance for the difference in oil pressure, and when the difference in the measured oil pressure exceeds 120 to 130% of the steady value, the unsolidified slab is drawn from the mold. The present invention is characterized in that it predicts the occurrence of breakout in the unsolidified slab to be pulled out from the mold as a dangerous state in which breakout will occur in the solidified slab. [Structure of the Invention] The present inventors have conducted extensive research in order to prevent the breakout that occurs when the frictional force between the unsolidified slab and the mold exceeds the high temperature strength of the unsolidified slab. . As a result, in a mold that is vibrated by hydraulic pressure, the difference in hydraulic pressure between the pushing side and the pushing back side of the hydraulic cylinder that gives vibration to the mold increases the frictional force between the mold and the unsolidified slab. Then, in order to try to keep the amplitude and frequency of the mold constant,
Therefore, by measuring this difference in oil pressure, we found that the lubrication state between the mold and the unsolidified slab can be determined from the change in the difference in oil pressure, and it is possible to predict the occurrence of breakout. . This invention was made based on the above findings. Next, the present invention will be explained based on the drawings. FIG. 1 is an explanatory diagram showing one embodiment of the present invention. In FIG. 1, 1 is a water box for a water-cooled mold 2, 3 is a mold frame for the mold 2, 4 is a mold support frame for supporting the mold 2, and 5 is an oscillation frame for vibrating the mold 2. A reciprocating hydraulic cylinder 6 is attached to one end of the oscillation frame 5, as shown in FIG. 7
Hydraulic pressure gauges 8a and 8b for measuring the oil pressure on the pushing side 6a and the pushing back side 6b are provided at b. The molten steel 9 injected into the vibrating mold 2 generates a solidified shell 10 within the mold 2 and becomes an unsolidified slab 1.
1, and is pulled out from the mold 2 while being supported by the slab support rolls 12. In this invention, changes in the oil pressure difference between the pushing side 6a and the pushing back side 6b of the hydraulic cylinder 6 are monitored, and thereby the mold 2 and the solidified shell 10 are
It is possible to predict the breakout of the unsolidified slab 11 by knowing the lubrication state between the unsolidified slab 11 and the unsolidified slab 11. That is, the mold 2 and the solidified shell 10 within the mold 2
When the lubrication state between the two is good and the unsolidified slab 11 is normally pulled out from the mold 2, the oil pressure on the push side 6a measured by the oil pressure gauge 8a and the oil pressure on the push back side measured by 8b. The difference ΔP from the oil pressure of 6b hardly changes. On the other hand, mold 2 and solidified shell 1
When the lubrication condition between the mold 2 and the unsolidified slab 11 deteriorates and the frictional force between the mold 2 and the unsolidified slab 11 increases, the oil pressure difference ΔP increases. The amount of variation △ (△P) = △P - △P 0 of this oil pressure difference △P with respect to the steady value △P 0 is:
Since it is determined by the magnitude of the frictional force between the mold 2 and the unsolidified slab 11, the lubrication state between the mold 2 and the solidified shell 10 can be known from this variation Δ(ΔP), and the Breakout of the solidified slab 11 can be detected in advance. The difference ΔP in the oil pressure of the hydraulic cylinder 6 when the frictional force causes a risk of breakout in the unsolidified slab 11 varies depending on the model of the continuous casting machine and the casting conditions, but is based on experience in actual operation. According to , it has been confirmed that it is sufficient to select 120 to 130% of the steady-state value ΔP 0 . Therefore, if a pressure of 120 to 130% of the steady value ΔP 0 is set as the upper limit of the oil pressure difference ΔP, only the dangerous situation where the unsolidified slab 11 breaks out can be selectively taken out. be able to. As described above, when the occurrence of a breakout of the unsolidified slab 11 is predicted from the change in the difference in oil pressure between the pushing side and the pushing back side of the hydraulic cylinder 6, from this prediction to the occurrence of the breakout,
There is a time margin of about 1 to 2 minutes, so if you take measures such as stopping the injection of molten steel 9 into the mold 2, lowering the injection speed, and changing the powder during this time, you can prevent breakouts from occurring. can do. [Examples of the Invention] Next, the present invention will be explained with reference to Examples. Thickness 250mm, width 1750mm with the composition shown in Table 1
A 40 kg class slab for thick plates is cast using a 10.5 mR curved continuous casting machine, and the hydraulic pressure difference △P between the push side and push back side of the hydraulic cylinder between them is
was measured continuously.
以上説明したように、この発明によれば、鋳型
を振動させる油圧シリンダーの押し側と押し戻し
側との間の油圧の差圧を測定することによつて、
その差圧の変化から鋳型と凝固シエルとの間の潤
滑状態を知るので、鋳型から引抜かれる未凝固鋳
片のブレークアウトを確実に予知することがで
き、ブレークアウトの発生を未然に防止すること
ができる。従つて、ブレークアウトの発生が障害
となつていた鋳造速度の高速化を可能にするな
ど、工業上優れた効果がもたらされる。
As explained above, according to the present invention, by measuring the differential pressure of the hydraulic pressure between the pushing side and the pushing back side of the hydraulic cylinder that vibrates the mold,
Since the lubrication state between the mold and the solidified shell is known from the change in differential pressure, it is possible to reliably predict the breakout of the unsolidified slab being pulled out of the mold, and to prevent the occurrence of breakout. Can be done. Therefore, excellent industrial effects are brought about, such as making it possible to increase the casting speed, which has been hampered by the occurrence of breakouts.
第１図はこの発明の方法の一実施態様を示す説
明図、第２図は第１図の方法において鋳型を振動
する油圧シリンダーの油圧の差を測定するところ
を示す説明図、第３図はこの発明の方法において
油圧シリンダーの油圧の差を測定したときの測定
値の一例を示すグラフである。図面において、
１……水箱、２……鋳型、３……鋳型フレー
ム、４……鋳型支持フレーム、５……オシレーシ
ヨンフレーム、６……油圧シリンダー、６ａ……
押し側、６ｂ……押し戻し側、７ａ，７ｂ……配
管、８ａ，８ｂ……油圧計、９……溶鋼、１０…
…凝固シエル、１１……未凝固鋳片。
Fig. 1 is an explanatory diagram showing one embodiment of the method of the present invention, Fig. 2 is an explanatory diagram showing the method of Fig. 1 in which the difference in oil pressure of the hydraulic cylinder that vibrates the mold is measured, and Fig. 3 is an explanatory diagram showing the method of Fig. 1. It is a graph which shows an example of the measured value when the difference in the oil pressure of a hydraulic cylinder is measured in the method of this invention. In the drawings, 1... Water box, 2... Mold, 3... Mold frame, 4... Mold support frame, 5... Oscillation frame, 6... Hydraulic cylinder, 6a...
Push side, 6b... Push back side, 7a, 7b... Piping, 8a, 8b... Oil pressure gauge, 9... Molten steel, 10...
...solidified shell, 11...unsolidified slab.
Claims (1)
めの油圧シリンダーの、押し側と戻し側との間の
油圧の差を連続的に測定し、一方、前記油圧の差
の、未凝固鋳片にブレークアウトの生ずることの
ない定常値を予め設定し、前記測定された油圧の
差が前記定常値の120〜130％を超えたときを、前
記鋳型から引抜かれる未凝固鋳片にブレークアウ
トが生ずる危険状態のときとして、前記鋳型から
引抜かれる未凝固鋳片のブレークアウトの発生を
予知することを特徴とする、連続鋳造におけるブ
レークアウト予知方法。1. In continuous casting of steel, the difference in oil pressure between the push side and the return side of a hydraulic cylinder for vibrating the mold is continuously measured, and on the other hand, the difference in oil pressure is applied to the unsolidified slab. A steady value that will not cause breakout is set in advance, and when the difference in the measured oil pressure exceeds 120 to 130% of the steady value, there is a risk of breakout occurring in the unsolidified slab pulled from the mold. 1. A breakout prediction method in continuous casting, comprising predicting the occurrence of a breakout in an unsolidified slab to be pulled from the mold.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17524884A JPH0235622B2 (en) | 1984-08-24 | 1984-08-24 | RENZOKUCHUZONIOKERUBUREEKUAUTOYOCHIHOHO |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17524884A JPH0235622B2 (en) | 1984-08-24 | 1984-08-24 | RENZOKUCHUZONIOKERUBUREEKUAUTOYOCHIHOHO |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6152973A JPS6152973A (en) | 1986-03-15 |
| JPH0235622B2 true JPH0235622B2 (en) | 1990-08-13 |
Family
ID=15992848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17524884A Expired - Lifetime JPH0235622B2 (en) | 1984-08-24 | 1984-08-24 | RENZOKUCHUZONIOKERUBUREEKUAUTOYOCHIHOHO |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0235622B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19614760A1 (en) * | 1996-04-02 | 1997-10-09 | Mannesmann Ag | Process for optimizing the strand surface quality |
| DE19915269A1 (en) * | 1999-04-03 | 2000-10-26 | Sms Demag Ag | Procedure for determining the friction between the continuous shell and the mold during continuous casting |
| WO2014003269A1 (en) * | 2012-06-28 | 2014-01-03 | 현대제철 주식회사 | Breakout prevention method in continuous casting |
| CN108620546B (en) * | 2017-03-24 | 2020-03-06 | 宝山钢铁股份有限公司 | Plug-in device for preventing continuous casting billet tail billet from rising and using method thereof |
-
1984
- 1984-08-24 JP JP17524884A patent/JPH0235622B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6152973A (en) | 1986-03-15 |
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