JP4752366B2 - Multi-frequency eddy current mold powder melt thickness measurement method - Google Patents
Multi-frequency eddy current mold powder melt thickness measurement method Download PDFInfo
- Publication number
- JP4752366B2 JP4752366B2 JP2005206536A JP2005206536A JP4752366B2 JP 4752366 B2 JP4752366 B2 JP 4752366B2 JP 2005206536 A JP2005206536 A JP 2005206536A JP 2005206536 A JP2005206536 A JP 2005206536A JP 4752366 B2 JP4752366 B2 JP 4752366B2
- Authority
- JP
- Japan
- Prior art keywords
- mold powder
- eddy current
- thickness
- mold
- absolute value
- 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 - Fee Related
Links
- 239000000843 powder Substances 0.000 title claims description 135
- 238000000691 measurement method Methods 0.000 title claims description 8
- 238000012937 correction Methods 0.000 claims description 31
- 238000005259 measurement Methods 0.000 claims description 29
- 238000000034 method Methods 0.000 claims description 25
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 16
- 229910052802 copper Inorganic materials 0.000 claims description 16
- 239000010949 copper Substances 0.000 claims description 16
- 238000009749 continuous casting Methods 0.000 claims description 12
- 239000000155 melt Substances 0.000 claims description 12
- 238000004364 calculation method Methods 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 6
- 238000013480 data collection Methods 0.000 claims description 5
- 229910000831 Steel Inorganic materials 0.000 description 60
- 239000010959 steel Substances 0.000 description 60
- 238000001514 detection method Methods 0.000 description 14
- 239000000463 material Substances 0.000 description 10
- 238000010586 diagram Methods 0.000 description 7
- 230000005284 excitation Effects 0.000 description 7
- 238000005266 casting Methods 0.000 description 5
- 239000004020 conductor Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000314 lubricant Substances 0.000 description 5
- 238000002844 melting Methods 0.000 description 5
- 230000008018 melting Effects 0.000 description 5
- 239000002585 base Substances 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 238000004088 simulation Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 230000002745 absorbent Effects 0.000 description 2
- 239000002250 absorbent Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- 230000003078 antioxidant effect Effects 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000012212 insulator Substances 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910004261 CaF 2 Inorganic materials 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 239000005909 Kieselgur Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- -1 cryolite Chemical class 0.000 description 1
- 229910001610 cryolite Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- VASIZKWUTCETSD-UHFFFAOYSA-N manganese(II) oxide Inorganic materials [Mn]=O VASIZKWUTCETSD-UHFFFAOYSA-N 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Landscapes
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
- Continuous Casting (AREA)
Description
本発明は、連続鋳造において潤滑剤などとして用いられているモールドパウダーの溶融層厚みを計測するための多周波渦流式モールドパウダー溶融厚み計測方法に関するものである。 The present invention relates to a multi-frequency eddy current mold powder melt thickness measuring method for measuring a melt layer thickness of a mold powder used as a lubricant or the like in continuous casting.
鋼の連続鋳造では、溶鋼を水冷構造の鋳型に注入して冷却し、鋳型との接触面に凝固シェルを生成させながら、この凝固シェルを鋳型下方に連続的に引き抜き、鋳片を製造している。この連続鋳造においては、銅を母材とし、その表面にクロムまたはニッケル若しくはこれら金属の合金が必要に応じてメッキされた鋳型銅板表面と、生成される凝固シェルとの摩擦抵抗を減じるために、潤滑剤としてモールドパウダーが使用されている。 In continuous casting of steel, molten steel is poured into a water-cooled mold and cooled, and a solidified shell is formed on the contact surface with the mold. Yes. In this continuous casting, in order to reduce the frictional resistance between the surface of the mold copper plate with copper as the base material and chromium or nickel or an alloy of these metals plated as necessary, and the solidified shell to be produced, Mold powder is used as a lubricant.
モールドパウダーは、ＣａＯ、ＳｉＯ2 、Ａｌ2 Ｏ3 、ＭｇＯ、ＭｎＯなどの酸化物を基材とし、これら基材に、基材の物性を調整するためのＮａ2Ｏ、Ｋ2 Ｏ、ＣａＦ2 、ＭｇＦ2 、Ｌｉ2 ＣＯ3、氷晶石などのアルカリ金属又はアルカリ土類金属の酸化物や弗化物または炭酸化物と、基材の主成分であるＣａＯ、ＳｉＯ2 の成分調整材である炭酸カルシウムや珪藻土と、溶融速度調整材であるカーボンブラック、人造黒鉛などの炭素物質と、が添加されて構成されており、鋳型内の溶鋼上に添加されたモールドパウダーは溶融して鋳型と凝固シェルとの間隙に流入し、潤滑剤としての機能を発揮する。尚、モールドパウダーは、その他に酸化防止剤、保温剤、溶鋼から浮上してくるアルミナなどの酸化物の吸収剤としての機能も有している。 The mold powder uses an oxide such as CaO, SiO 2 , Al 2 O 3 , MgO, or MnO as a base material, and Na 2 O, K 2 O, CaF 2 for adjusting the physical properties of the base material to these base materials. , MgF 2 , Li 2 CO 3 , oxides or fluorides or carbonates of alkali metals or alkaline earth metals such as cryolite, and carbon dioxide as a component adjusting material for CaO and SiO 2 as the main components of the substrate Calcium and diatomaceous earth, and carbon materials such as carbon black and artificial graphite, which are melting rate modifiers, are added to the mold, and the mold powder added on the molten steel in the mold is melted to form the mold and the solidified shell. It flows into the gap between the two and exerts the function as a lubricant. The mold powder also has a function as an antioxidant, a heat retaining agent, and an absorbent for oxides such as alumina floating from molten steel.
鋳型内に添加されたモールドパウダーは、溶鋼の熱によって加熱され、溶鋼と接触する側が溶融する。モールドパウダーの潤滑剤としての機能或いは酸化物吸収剤としての機能などは、モールドパウダーの溶融層の厚みに依存することから、鋳造中にモールドパウダーの溶融層厚みを計測し、その厚みを調整することは連続鋳造操業の安定化につながる。そのため、正確に且つ迅速にモールドパウダーの溶融層厚みを計測する手段が切望されていた。 The mold powder added to the mold is heated by the heat of the molten steel, and the side in contact with the molten steel is melted. Since the function of the mold powder as a lubricant or the function of an oxide absorber depends on the thickness of the molten layer of the mold powder, the thickness of the molten layer of the mold powder is measured during casting and the thickness is adjusted. This leads to stabilization of continuous casting operations. Therefore, a means for accurately and quickly measuring the melt layer thickness of the mold powder has been desired.
従来、モールドパウダーの溶融層厚みを計測する手段としては、金属製の検知棒を鋳型内の溶鋼湯面に浸漬させた後に引き上げ、検知棒に固化付着したモールドパウダー層の厚みから溶融厚みを推定する方法が主として行われていたが、測定者による測定誤差が生じたり、溶鋼中に浸漬させることから品質上の問題が発生したりする場合もあった。 Conventionally, as a means of measuring the melt layer thickness of the mold powder, the metal detection rod is immersed in the molten steel surface in the mold and then pulled up, and the melt thickness is estimated from the thickness of the mold powder layer solidified and adhered to the detection rod. However, there are cases in which measurement errors by the measurer occur and quality problems occur due to immersion in the molten steel.
これらの問題を解決するために、本発明者等は、これまでに特許文献１に示す、複数の周波数を用い、各周波数における位相と絶対値の双方を用いてモールドパウダーの溶融厚みを計測する多周波渦流式モールドパウダー溶融厚み計測器を提案した。この計測器を用いることで、極めて容易に且つ連続してモールドパウダーの溶融厚みを計測することが可能となった。また、高精度に計測を行うため、特許文献２に示す、校正方法も提案している。
しかしながら、上述の特許文献１および特許文献２の技術を利用する際に、条件によっては精度が悪くなる場合があった。例えば、パウダーの種類、溶鋼面温度によって溶融厚計測誤差が大きくなったり、製造する鋳造片の厚み（すなわち長辺銅板間隔）が狭くなると溶鋼レベル計測精度が悪くなる、オシレーション（鋳型の上下振動）の振動パターンによってはデータがばらつくなどである。 However, when using the techniques of Patent Document 1 and Patent Document 2 described above, accuracy may be deteriorated depending on conditions. For example, when the molten thickness measurement error increases depending on the powder type and molten steel surface temperature, or when the thickness of the cast piece to be manufactured (that is, the distance between the long side copper plates) becomes narrow, the molten steel level measurement accuracy deteriorates. ) Varies depending on the vibration pattern.
上記のうち、銅板間隔の影響は、その影響が溶鋼レベルの反応ベクトルと同方向であるため、溶融モールドパウダーが無い状況で、溶鋼面模擬材を使用し、銅板の影響を調査することが出来、補正式も構築が可能である。また、オシレーションの影響も信号の加算平均時間を振動パターン１周期と同期させることで除去可能である。 Of the above, the effect of the copper plate spacing is in the same direction as the reaction vector at the molten steel level, so in the absence of molten mold powder, the effect of the copper plate can be investigated using the molten steel surface simulation material. A correction formula can also be constructed. Further, the influence of oscillation can be removed by synchronizing the signal addition average time with one period of the vibration pattern.
しかしモールドパウダーの種類、溶鋼面温度が変わった場合の問題は、その誤差の大きさが種類、温度ごとに変わり、単純ではない。その原因は溶融モールドパウダー層内の導電率の分布であるが、溶融モールドパウダーの導電率はその温度に応じて変化し、かつ溶融層内の温度分布は溶鋼面温度によって変わるためである。 However, the problem when the type of mold powder and the molten steel surface temperature change is not simple because the magnitude of the error changes with the type and temperature. This is because the electrical conductivity distribution in the molten mold powder layer changes depending on the temperature of the molten mold powder, and the temperature distribution in the molten layer changes depending on the molten steel surface temperature.
本発明は上記事情に鑑みてなされたもので、その目的とするところは、連続鋳造において鋳型内に添加されたモールドパウダーの溶融厚みを多周波渦流式モールドパウダー溶融厚み計測方法で計測するに当たり、モールドパウダーの種類と溶鋼面温度の影響による誤差を補正して、モールドパウダー種類、溶鋼面温度によらず高精度に計測を行う多周波渦流式モールドパウダー溶融厚み計測方法を提供することを目的とする。 The present invention has been made in view of the above circumstances, the purpose of which is to measure the melt thickness of the mold powder added in the mold in the continuous casting by a multi-frequency eddy current mold powder melt thickness measurement method, The purpose is to provide a multi-frequency eddy current mold powder melt thickness measurement method that corrects errors due to the effects of mold powder type and molten steel surface temperature, and performs measurement with high accuracy regardless of mold powder type and molten steel surface temperature. To do.
［１］少なくとも２種以上の周波数における位相情報と絶対値情報とを用いて、連続鋳造鋳型内の溶融金属上に添加されたモールドパウダーの溶融層の厚みを計測する多周波渦流式モールドパウダー溶融厚み計測方法であって、
前記位相情報と絶対値情報とを得るための計測データ収集工程と、
該計測データ収集工程にて収集した前記位相情報と前記絶対値情報の各データを
銅板間隔に対して補正する第一の補正工程と、
前記第一の補正工程で補正された前記位相情報と前記絶対値情報の各データを
前記モールドパウダーの溶融層内の渦電流密度分布に基づいて補正する第二の補正工程と、
該第二の補正工程にて補正した前記位相情報と前記絶対値情報の各データに基づいて、モールドパウダーの溶融層の厚みを演算する演算工程と、
を有することを特徴とする多周波渦流式モールドパウダー溶融厚み計測方法。
[1] Multi-frequency eddy current mold powder melting that measures the thickness of the molten layer of the mold powder added on the molten metal in the continuous casting mold using phase information and absolute value information at at least two frequencies. A thickness measurement method,
A measurement data collection step for obtaining the phase information and absolute value information;
Each data of the phase information and the absolute value information collected in the measurement data collecting step
A first correction step for correcting the copper plate spacing ;
Each data of the phase information and the absolute value information corrected in the first correction step
A second correction step for correcting based on the eddy current density distribution in the molten layer of the mold powder;
A calculation step of calculating the thickness of the molten layer of the mold powder based on each data of the phase information and the absolute value information corrected in the second correction step,
A multi-frequency eddy current mold powder melt thickness measuring method characterized by comprising:
［２］少なくとも２種以上の周波数における位相情報と絶対値情報とを用いて、連続鋳造鋳型内の溶融金属上に添加されたモールドパウダーの溶融層の厚みを計測する多周波渦流式モールドパウダー溶融厚み計測方法であって、
前記位相情報と絶対値情報とを得るための計測データ収集工程と、
該計測データ収集工程にて収集した前記位相情報と前記絶対値情報の各データを
前記モールドパウダーの溶融層内の渦電流密度分布に基づいて補正する第一の補正工程と、
前記第一の補正工程で補正された前記位相情報と前記絶対値情報の各データを
銅板間隔に対して補正する第二の補正工程と、
該第二の補正工程にて補正した前記位相情報と前記絶対値情報の各データに基づいて、モールドパウダーの溶融層の厚みを演算する演算工程と、
を有することを特徴とする多周波渦流式モールドパウダー溶融厚み計測方法。
[2] Multi-frequency vortex mold powder melting that measures the thickness of the molten layer of the mold powder added on the molten metal in the continuous casting mold using phase information and absolute value information at at least two frequencies. A thickness measurement method,
A measurement data collection step for obtaining the phase information and absolute value information;
Each data of the phase information and the absolute value information collected in the measurement data collecting step
A first correction step for correcting based on the eddy current density distribution in the molten layer of the mold powder ;
Each data of the phase information and the absolute value information corrected in the first correction step
A second correction step for correcting the copper plate interval;
A calculation step of calculating the thickness of the molten layer of the mold powder based on each data of the phase information and the absolute value information corrected in the second correction step,
A multi-frequency eddy current mold powder melt thickness measuring method characterized by comprising:
［２］前記［１］または［２］に記載の多周波渦流式モールドパウダー溶融厚み計測方法において、
前記渦電流密度分布を、
モールドパウダー種類に対応して該モールドパウダーの導電率温度依存データと溶融層層内の厚み方向温度分布から求めることを特徴とする多周波渦流式モールドパウダー溶融厚み計測方法。
[2] In the multi-frequency eddy current mold powder melt thickness measuring method according to [1] or [2] ,
The eddy current density distribution is
A multi-frequency eddy current mold powder melt thickness measuring method characterized in that it is obtained from the conductivity temperature dependence data of the mold powder and the thickness direction temperature distribution in the melt layer corresponding to the mold powder type .
本発明では、多周波渦流式モールドパウダー溶融厚み計測においてモールドパウダーの種類と溶鋼面温度の影響による誤差の補正を、パウダーの導電率と溶鋼面温度の関係から得られる溶融層内の渦電流密度分布に基づいて行うようにしたので、モールドパウダー種類、溶鋼面温度によらず高精度にモールドパウダー溶融厚み計測を行うことができる。 In the present invention, in the multi-frequency eddy current type mold powder melt thickness measurement, the error due to the influence of the mold powder type and the molten steel surface temperature is corrected, and the eddy current density in the molten layer obtained from the relationship between the electrical conductivity of the powder and the molten steel surface temperature. Since it performed based on distribution, mold powder melt thickness measurement can be performed with high precision irrespective of mold powder kind and molten steel surface temperature.
本発明を、スラブ連続鋳造機で溶鋼を鋳造する場合に適用した例を用いて、以下具体的に説明する。 The present invention will be described in detail below using an example applied when casting molten steel with a slab continuous casting machine.
鋼の連続鋳造では、溶鋼を水冷構造の鋳型に注入して冷却し、鋳型との接触面に凝固シェルを生成させながら、この凝固シェルを鋳型下方に連続的に引き抜き、連続鋳造鋳片を製造している。鋳型内には、凝固シェルと鋳型との潤滑剤、溶鋼の酸化防止剤、溶鋼の保温剤、及び溶鋼から浮上してくるアルミナなどの酸化物の吸収剤として、モールドパウダーが添加される。添加されたモールドパウダーは、溶鋼を覆い、溶鋼から熱を受け、溶鋼と接触する側は溶融して溶融層を形成する。溶融したモールドパウダーは凝固シェルと鋳型との間隙を流下して消費されるので、この消費量に応じて新たにモールドパウダーが鋳型内に添加される。 In continuous casting of steel, molten steel is poured into a water-cooled mold and cooled, and a solidified shell is formed on the contact surface with the mold. is doing. Mold powder is added into the mold as a lubricant between the solidified shell and the mold, an antioxidant for the molten steel, a heat insulating agent for the molten steel, and an absorbent for oxides such as alumina floating from the molten steel. The added mold powder covers the molten steel, receives heat from the molten steel, and melts the side in contact with the molten steel to form a molten layer. Since the melted mold powder flows down the gap between the solidified shell and the mold, the mold powder is newly added into the mold in accordance with the consumption amount.
モールドパウダーの溶融層の厚みは、流下して消費される量と新たに溶融される量とで決定されるが、鋳造条件が変化するとモールドパウダーの消費量が変化し、それに応じてモールドパウダーの溶融層厚みも変動する。この溶融層厚みが薄くなると、未溶融のモールドパウダーが溶鋼に巻き込まれるなどして鋳片の品質欠陥の原因になるのみならず、鋳型と凝固シェルとの潤滑が不足し、ブレークアウトを発生する恐れもある。そのため、モールドパウダーの溶融層の厚みを計測し、管理することが極めて重要となる。モールドパウダーは、その鋳造条件によりパウダーの種類を変えることがあり、そのパウダーの種類は化学組成も異なり、溶融物性（粘性、導電率、融点等）もそれぞれ異なる。 The thickness of the molten layer of the mold powder is determined by the amount consumed by flowing down and the amount melted newly, but when the casting conditions change, the amount of mold powder consumed changes accordingly. The melt layer thickness also varies. If the thickness of the molten layer is reduced, unmelted mold powder is caught in the molten steel, causing not only the quality defect of the slab, but also the lack of lubrication between the mold and the solidified shell, causing breakout. There is also a fear. Therefore, it is extremely important to measure and manage the thickness of the molten layer of the mold powder. Mold powder may change the type of powder depending on the casting conditions. The type of powder is different in chemical composition, and the melt physical properties (viscosity, electrical conductivity, melting point, etc.) are also different.
鋳型内の溶鋼及びモールドパウダーの状態を示す概略図を、図１に示す。図１に示すように、溶鋼２の上に添加されたモールドパウダー４は、溶鋼２の熱によって溶融し、溶鋼２と接触する側の溶融層５と、その上の未溶融の粉末層６との２層になっている。図中、符号１は鋳型銅板、符号３は溶鋼２が冷却されて生成した凝固シェルである。尚、凝固シェル３と鋳型銅板１との間隙をモールドパウダー４が流下しているが、図１では込み入って区別がつきにくいので、流下するモールドパウダー４は省略している。 A schematic diagram showing the state of molten steel and mold powder in the mold is shown in FIG. As shown in FIG. 1, the mold powder 4 added on the molten steel 2 is melted by the heat of the molten steel 2, the molten layer 5 on the side in contact with the molten steel 2, and the unmelted powder layer 6 thereon It has two layers. In the figure, reference numeral 1 denotes a mold copper plate, and reference numeral 3 denotes a solidified shell formed by cooling the molten steel 2. Although the mold powder 4 flows down the gap between the solidified shell 3 and the mold copper plate 1, the mold powder 4 that flows down is omitted because it is complicated and difficult to distinguish in FIG. 1.
ここで、本発明において補正の対象とする多周波渦流式モールドパウダー溶融厚み計測装置（以下、「多周波渦流式厚み計測器」とも記す）について説明する。 Here, a multi-frequency eddy current mold powder melt thickness measuring device (hereinafter also referred to as “multi-frequency eddy current thickness measuring device”) to be corrected in the present invention will be described.
溶鋼２、溶融層５、粉末層６の導電率を表１に示す。溶融層５の導電率は溶融させたモールドパウダーで計測し、粉末層６の導電率は、粉末状態のモールドパウダーで計測した値である。表１に示すように、溶鋼２の導電率は非常に大きく、それに対して溶融層５の導電率は小さい。一方、粉末層６の導電率は極めて小さくほぼ絶縁体に近い。本発明で補正の対象とする多周波渦流式厚み計測器は、計測器から溶鋼２の表面即ち溶鋼湯面位置２ａまでの距離と、モールドパウダー４の溶融層５の厚みと、を計測するための装置である。 Table 1 shows the electrical conductivity of the molten steel 2, the molten layer 5, and the powder layer 6. The electrical conductivity of the molten layer 5 is measured with a molten mold powder, and the electrical conductivity of the powder layer 6 is a value measured with a powdered mold powder. As shown in Table 1, the conductivity of the molten steel 2 is very large, whereas the conductivity of the molten layer 5 is small. On the other hand, the electrical conductivity of the powder layer 6 is extremely small and almost close to an insulator. The multi-frequency eddy current thickness measuring instrument to be corrected in the present invention measures the distance from the measuring instrument to the surface of the molten steel 2, that is, the molten steel surface position 2a, and the thickness of the molten layer 5 of the mold powder 4. It is a device.
渦流法は、図２にその計測方法の原理を示すように、励磁コイルの信号と検出コイルの信号とを検波して、検出コイルのインピーダンス変化を計測する方法であるが、検出コイルのインピーダンスは、設計仕様の他に、検出コイルの周辺状況、例えば検出コイルに対する導電体の距離、導電体の導電率の変化などによっても変化する。ここで、インピーダンスは複素数であり、絶対値（電圧）と位相情報の２つの情報がある。即ち、１つの周波数について２つのデータが得られることになる。これらの絶対値及び位相情報の概念を図３に示す。図３において、実線の波は励磁コイルへの入力、破線の波は検出コイルの出力であり、絶対値とは、検出コイルの出力の最大値と最小値との差であり、位相情報とは、励磁コイルに入力した信号に対する位相差である。 As shown in FIG. 2, the eddy current method is a method of detecting the excitation coil signal and the detection coil signal and measuring the impedance change of the detection coil. In addition to the design specification, it varies depending on the surrounding conditions of the detection coil, for example, the distance of the conductor relative to the detection coil, the change in the conductivity of the conductor, and the like. Here, the impedance is a complex number, and there are two pieces of information: absolute value (voltage) and phase information. That is, two data are obtained for one frequency. The concept of these absolute values and phase information is shown in FIG. In FIG. 3, the solid wave is the input to the excitation coil, the broken wave is the output of the detection coil, the absolute value is the difference between the maximum and minimum values of the output of the detection coil, and the phase information The phase difference with respect to the signal input to the excitation coil.
鋳型内の溶鋼湯面位置２ａを計測するための渦流式湯面計測器などのように測定対象が１つならば、１つの周波数で絶対値のみを測定することで計測が可能であるが、モールドパウダー４の溶融層５の厚みを精度良く計測するためには、溶鋼湯面位置２ａ及びモールドパウダー４の粉末層６の影響を加味する必要があり、計測の対象として３種類の対象を計測する必要がある。そのためには、少なくとも３種類の周波数を用いるか、２種類の周波数でそれぞれの絶対値と位相情報とを利用するなどして、とにかく３種類以上のデータが必要である。本発明の補正対象である多周波渦流式厚み計測器では、この点を解決しており、複数の周波数における絶対値と位相情報とを利用して計測・解析し、モールドパウダー４の溶融層５の厚みを計測するようにしている。 If there is only one object to be measured, such as a vortex flow level measuring instrument for measuring the molten steel surface level 2a in the mold, measurement is possible by measuring only the absolute value at one frequency. In order to accurately measure the thickness of the molten layer 5 of the mold powder 4, it is necessary to consider the influence of the molten steel surface position 2a and the powder layer 6 of the mold powder 4, and three types of objects are measured. There is a need to. For that purpose, at least three types of data are required, either using at least three types of frequencies or using the absolute values and phase information of the two types of frequencies. The multi-frequency eddy current type thickness measuring instrument which is a correction target of the present invention solves this point, and performs measurement / analysis using absolute values and phase information at a plurality of frequencies to obtain a molten layer 5 of the mold powder 4. The thickness is measured.
では、本発明について以下に詳細説明を行う。図４は、本発明の実施の形態の１例を示す図であって、モールドパウダーの溶融層厚み計測方法とその補正方法のフローの概略図である。図５は、多周波渦流式厚み計測器の全体概略図である。 Now, the present invention will be described in detail below. FIG. 4 is a diagram showing an example of an embodiment of the present invention, and is a schematic diagram of a flow of a mold powder molten layer thickness measurement method and a correction method thereof. FIG. 5 is an overall schematic diagram of a multi-frequency eddy current thickness measuring instrument.
先ず図５を用いて、多周波渦流式厚み計測器の全体概要を説明する。計測に入る前に０（ゼロ）点校正として、所定（例えば１００ｍｍ）の距離に溶鋼模擬材（例えばＳＵＳ３０４、３００ｍｍ角厚み１ｍｍ）を設置し、その信号データを１００ｍｍのデータとして記録する。その後鋳型上へ移動し、鋳型内の溶鋼２に対向して多周波渦流式厚み計測器の多周波渦流センサー１１を設置する。上下移動可能な保持台８を介して架台７に設置されている。溶鋼２は、モールドパウダー４の溶融層５で覆われ、溶融層５は、未溶融の粉末層６で覆われている。 First, an overall outline of a multi-frequency eddy current thickness measuring instrument will be described with reference to FIG. Before starting the measurement, as a zero (zero) point calibration, a molten steel simulated material (eg, SUS304, 300 mm square thickness: 1 mm) is set at a predetermined (eg, 100 mm) distance, and the signal data is recorded as 100 mm data. Thereafter, the multi-frequency eddy current sensor 11 of the multi-frequency eddy current type thickness measuring instrument is installed facing the molten steel 2 in the mold. It is installed on the gantry 7 via a holding table 8 that can move up and down. The molten steel 2 is covered with a molten layer 5 of mold powder 4, and the molten layer 5 is covered with an unmelted powder layer 6.
多周波渦流センサー１１は、空芯或いは絶縁体または非磁性のボビンに巻かれたコイルからなり、励磁コイル１３と検出コイル１４とから構成される。多周波渦流センサー１１は、計測中に冷却できるようにケース１２を外殻とし、外部からケース１２の内部に導入される空気によってエアーパージされる構造である。励磁コイル１３には、発振器１５から出力された基本波形が電源アンプ１６で増幅されて入力される。検出コイル１４にて検出された信号は、差動アンプ１７で増幅された後、ロックインアンプ１８へ入力される。発振器１５から別途基本波形をロックインアンプ１８へ参照波形として入力し、検波出力として絶対値と位相とが得られる。発振器１５からの信号の周波数を変えることにより、多周波での計測が可能な計測器である。 The multi-frequency eddy current sensor 11 includes an air core, an insulator, or a coil wound around a nonmagnetic bobbin, and includes an excitation coil 13 and a detection coil 14. The multi-frequency eddy current sensor 11 has a case 12 as an outer shell so that it can be cooled during measurement, and is purged with air introduced into the case 12 from the outside. The basic waveform output from the oscillator 15 is amplified by the power amplifier 16 and input to the exciting coil 13. The signal detected by the detection coil 14 is amplified by the differential amplifier 17 and then input to the lock-in amplifier 18. A basic waveform is separately input from the oscillator 15 to the lock-in amplifier 18 as a reference waveform, and an absolute value and a phase are obtained as a detection output. This is a measuring instrument capable of measuring at multiple frequencies by changing the frequency of the signal from the oscillator 15.
次に、図４に基づいてモールドパウダーの溶融層厚み計測方法とその補正方法の処理フローを説明していく。Step100では、計測の前に０点校正のための校正データ収集を行う。このステップは、図５での説明のように実際のモールド上に溶鋼模擬材の良導体を所定のリフトオフをおいて行ってもよいし、多周波渦流センサー１１をオフラインに移動して溶鋼模擬材の良導体を用いて行ってもよい。 Next, the processing flow of the mold powder melt layer thickness measuring method and its correction method will be described with reference to FIG. In Step 100, calibration data collection for zero point calibration is performed before measurement. In this step, as shown in FIG. 5, the good conductor of the molten steel simulated material may be placed on the actual mold with a predetermined lift-off, or the multi-frequency eddy current sensor 11 is moved offline to You may carry out using a good conductor.
そして、Step101では、図５を用いて説明した多周波渦流式厚み計測器を用いて、計測データ（絶対値（電圧）と位相差）の収集を行う。 In Step 101, measurement data (absolute value (voltage) and phase difference) is collected using the multi-frequency eddy current thickness measuring instrument described with reference to FIG.
Step102では、計測されたデータに対して、銅板間隔の補正を行う。銅板間隔が変化した影響を、鋳造条件設定時に入力された長辺銅板間隔（例えば２２０ｍｍ）に対して補正式にて補正するものであり、この影響は主に溶鋼レベル変化と同じベクトル方向に出てくる。ここで用いる補正式（間隔の関数など）は、溶融モールドパウダーが無い状況で、溶鋼面模擬材を使用し、溶鋼模擬材の表面までの距離変化を検出するためのベクトル１式分の銅板に対する影響を調査し補正式を求めておき、事前に用意しておく。 In Step 102, the copper plate interval is corrected for the measured data. The effect of changing the copper plate interval is corrected with a correction formula for the long side copper plate interval (for example, 220 mm) input when setting the casting conditions, and this effect mainly appears in the same vector direction as the molten steel level change. Come. The correction formula (function of interval, etc.) used here is for the copper plate for one vector set for detecting the change in distance to the surface of the molten steel simulated material using the molten steel surface simulated material in the absence of molten mold powder. Investigate the impact, find the correction formula, and prepare it in advance.
Step103では、さらに使用するモールドパウダーの種類に応じて、補正を加えるステップであり、後に詳述する。なおここでの説明では、Step102を先に行うようになっているが、パウダー溶融層厚などの演算を行うStep104の開始までに、両ステップが終了していればよく、どちらが先であるかは問題ではない。 In Step 103, correction is further made in accordance with the type of mold powder to be used, which will be described in detail later. In the description here, Step 102 is performed first, but it is sufficient that both steps have been completed before the start of Step 104 for calculating the powder melt layer thickness, etc. is not a problem.
そしてStep104では、補正されたデータは、溶鋼レベル・パウダー溶融厚・粉末層厚の計測及び実測を所定の回数以上行って、多周波渦流センサー１１と実測値との対応付けにより予め導出されている溶鋼レベルおよび層厚のための算出式に代入される。これにより、溶鋼レベル、モールドパウダー粉末層厚、そしてモールドパウダー溶融層厚が算出される。そして、算出された溶鋼レベル、モールドパウダー粉末層厚、およびモールドパウダー溶融層厚は、表示または記憶（Step105）されて一連の計測処理が終了する。なおオシレーションの影響が大きい場合には、ここの演算過程またはそれ以前のステップにて、信号の加算平均時間を振動パターン１周期と同期させることで、オシレーションの影響除去を適宜行うようにするとよい。 In Step 104, the corrected data is derived in advance by associating the multi-frequency eddy current sensor 11 with the actual measurement value by performing measurement and actual measurement of the molten steel level, powder melt thickness, and powder layer thickness more than a predetermined number of times. Substituted into formulas for molten steel level and layer thickness. Thereby, the molten steel level, the mold powder powder layer thickness, and the mold powder molten layer thickness are calculated. Then, the calculated molten steel level, mold powder powder layer thickness, and mold powder melt layer thickness are displayed or stored (Step 105), and a series of measurement processes is completed. When the influence of the oscillation is large, the influence of the oscillation is appropriately removed by synchronizing the signal addition average time with one period of the vibration pattern in the calculation process or the previous step. Good.
では、モールドパウダーの種類による補正の具体例を以下に示す。図４のStep103では、事前に溶融モールドパウダーの導電率データなどを用意し、これに基づき補正を行う。図６は、溶融パウダーの導電率温度依存性の例を示す図である。図に示すように、モールドパウダーの導電率は、温度上昇に伴なって値が大きくなる。一方、鋳型内のモールドパウダー溶融層内には、溶鋼との境界面から粉末層に至る間で、図７で示される層内温度分布がある。図７は層内温度を実測した実測値であるが、溶鋼面の温度が与えられれば、パウダーの熱伝導率等から温度分布を推定することができる。 Then, the specific example of correction | amendment by the kind of mold powder is shown below. In Step 103 of FIG. 4, conductivity data of the molten mold powder is prepared in advance, and correction is performed based on this. FIG. 6 is a diagram showing an example of the temperature dependence of the conductivity of the molten powder. As shown in the figure, the conductivity of the mold powder increases as the temperature rises. On the other hand, in the mold powder molten layer in the mold, there is a temperature distribution in the layer shown in FIG. 7 from the boundary surface with the molten steel to the powder layer. FIG. 7 shows actual measurement values obtained by actually measuring the temperature in the layer. If the temperature of the molten steel surface is given, the temperature distribution can be estimated from the thermal conductivity of the powder.
以上のように溶融層内に温度分布（図７）があり、溶融パウダーの導電率温度依存性（図６）があるため、図６・図７に基づけば鋳型内のモールドパウダー溶融層内には導電率の分布が得られ、図８に示すような分布が存在することとなる。深さ方向に導電率が一定ならば、渦電流の原理から、センサに近い場所ほど渦電流密度が大きくなる。また、渦電流密度が大きいほどセンサの出力も大きくなるため、実質的にセンサに最も近い場所を計測することになる。逆に、導電率が深さ方向に分布をもつ場合は、導電率が大きい場所ほど渦電流密度も大きくなるので、実質的にセンサに最も近い場所でなく、導電率の大きい場所の影響を受けたセンサ出力となり、同じ厚さでも結果が異なる。 As described above, there is a temperature distribution in the molten layer (FIG. 7) and the conductivity temperature dependence of the molten powder (FIG. 6). Therefore, based on FIGS. 6 and 7, the mold powder is melted in the mold powder molten layer in the mold. A conductivity distribution is obtained, and a distribution as shown in FIG. 8 exists. If the conductivity is constant in the depth direction, the eddy current density increases as the position is closer to the sensor due to the principle of eddy current. Moreover, since the output of the sensor increases as the eddy current density increases, a location that is substantially closest to the sensor is measured. Conversely, when the conductivity has a distribution in the depth direction, the higher the conductivity, the higher the eddy current density. Therefore, it is affected not by the location closest to the sensor but by the location with the higher conductivity. The sensor output is different, and the results are different even with the same thickness.
しかし図８の如く分布が存在する場合には、必ずしもセンサに最も近い場所が渦電流密度が最大になるとは限らない。そこで、図８に示す導電率分布を有する場合のモールドパウダー溶融層内の渦電流密度の分布を電磁気シミュレーションにて計算した。図９は、渦電流密度を計算するための計算モデル例を示す図である。層０は空気、層１はモールドパウダー溶融層、層２は溶鋼（良導体）をそれぞれ示している。厚さ１７ｍｍの層１の上方１００ｍｍに、φ７０ｍｍの励磁コイルを設置し、図１０のグラフで示す導電率分布を層１に与えた場合の渦電流密度を有限要素法にて計算した。 However, when a distribution exists as shown in FIG. 8, the eddy current density is not necessarily maximized at a location closest to the sensor. Therefore, the distribution of the eddy current density in the molten mold powder layer having the conductivity distribution shown in FIG. 8 was calculated by electromagnetic simulation. FIG. 9 is a diagram illustrating a calculation model example for calculating the eddy current density. Layer 0 represents air, layer 1 represents a mold powder molten layer, and layer 2 represents molten steel (good conductor). An eddy current density was calculated by the finite element method when an excitation coil of φ70 mm was installed 100 mm above the layer 1 having a thickness of 17 mm and the conductivity distribution shown in the graph of FIG.
図１１は、渦電流密度の計算結果の例を示す図であり、コイル中心直下（中心軸）から３０ｍｍ外側での渦電流密度分布を表している。図１１では、１７ｍｍの全厚に対し、渦電流密度は約１０.５ｍｍの位置で最大となり、最大値付近の位置で渦電流分布が平たい分布形状であることが分る。 FIG. 11 is a diagram showing an example of the calculation result of the eddy current density, and represents the eddy current density distribution on the outside of the coil center by 30 mm from directly below (center axis). In FIG. 11, it can be seen that the eddy current density is maximum at a position of about 10.5 mm with respect to the total thickness of 17 mm, and the eddy current distribution is flat at a position near the maximum value.
上述の導電率温度分布を有するパウダー(導電率Ｂ)と異なる導電率温度分布を有するパウダー(導電率Ａ)について、同様の計算を行い、両者を比較したのが、図１２および１３である。なお、ここで比較した２種類のパウダー(導電率Ａと導電率Ｂ)は、両者とも一般的な使用されているパウダーであり、連続鋳造の操業において特別に差の大きなものではない。図１２に示す他の導電率分布（導電率Ｂは図８と同じ）で調べてみると、全厚に対する差がさらに大きくなる。例えば図１２導電率Ａの場合には、図１３の如きグラフになり、導電率Ｂと同じ厚さであっても渦電流密度の絶対値が小さい上に、最大値前後の渦電流分布が尖がっているため、全体の渦電流密度が小さく、センサ出力も小さくなる。もし導電率Ｂに対応する式で解析を行うと、検出信号が小さくなるので層厚が薄いと判断し、１７ｍｍの全厚に対し、例えば約８ｍｍと小さく算出されてしまうといった具合に、誤差がでてしまう。 FIGS. 12 and 13 show the same calculation for the powder having the conductivity temperature distribution (conductivity B) different from the powder having the conductivity temperature distribution described above (conductivity A), and comparing both. Note that the two types of powders (conductivity A and conductivity B) compared here are both commonly used powders, and are not particularly different in continuous casting operations. When the other conductivity distribution shown in FIG. 12 (conductivity B is the same as in FIG. 8) is examined, the difference with respect to the total thickness is further increased. For example, in the case of conductivity A in FIG. 12, a graph as shown in FIG. 13 is obtained. The absolute value of the eddy current density is small and the eddy current distribution around the maximum value is sharp even if the thickness is the same as the conductivity B. Therefore, the overall eddy current density is small and the sensor output is also small. If the analysis corresponding to the conductivity B is performed, the detection signal becomes small, so the layer thickness is judged to be thin, and the error is calculated such that the total thickness of 17 mm is calculated as small as about 8 mm, for example. It will be out.
パウダーの種類が変わり、計測誤差がでるといった場合には、予め渦電流分布をシミュレーションにて推測し、その誤差を補正する必要が出てくる。補正方法は、単純に係数をかける方法（上記の例のように、導電率Ｂのパウダーに変えて、導電率Ａのパウダーを使用する際は、係数として２．１を乗ずる等）もあれば、多次元関数を当てはめる等の補正式を準備する方法もある。
パウダー種毎に導電率と溶融層内温度分布を準備し、それらから渦電流密度を計算すれば、補正係数は得られる。導電率は、るつぼと白金電極にて測定可能であるし、他の物性（熱伝導率、粘性等）から類推することもできる（例えば、溶鉄・溶滓の物性値便覧、鉄鋼基礎共同研究会、溶鋼・溶滓部会編集、日本鉄鋼協会発行、1972年）。温度分布については、熱電対を埋め込んだセラミック棒をゆっくりと浸漬させて厚み方向分布を測定する方法がある。 逆に、いくつかのパウダー種の補正データが有れば、未知のパウダーに対する計測値とモールドパウダー溶融厚実測値から、未知のパウダーの導電率分布を予測することもできる。
When the type of powder changes and a measurement error occurs, it is necessary to estimate the eddy current distribution by simulation in advance and correct the error. There is also a correction method in which a coefficient is simply applied (when the powder of conductivity A is used instead of the powder of conductivity B as in the above example, the coefficient is multiplied by 2.1, etc.) There is also a method of preparing a correction formula such as applying a multidimensional function.
If the conductivity and the temperature distribution in the molten layer are prepared for each powder type, and the eddy current density is calculated from them, the correction coefficient can be obtained. Conductivity can be measured with a crucible and a platinum electrode, and can be inferred from other physical properties (thermal conductivity, viscosity, etc.) Edited by Molten Steel and Hot Metal Subcommittee, published by Japan Iron and Steel Institute, 1972). As for the temperature distribution, there is a method of measuring the thickness direction distribution by slowly immersing a ceramic rod embedded with a thermocouple. On the other hand, if there are correction data for several types of powder, the conductivity distribution of the unknown powder can be predicted from the measured value for the unknown powder and the actual measured value of the mold powder melt thickness.
以上説明したように、本発明によれば、多周波渦流式モールドパウダー溶融厚み計測器の補正を、使用している溶融モールドパウダーの導電率と溶鋼面温度の関係を用いて行うので、モールドパウダーの種類に係らず計測精度が安定、向上する。 As described above, according to the present invention, the correction of the multi-frequency eddy current mold powder melting thickness measuring device is performed using the relationship between the conductivity of the molten mold powder being used and the molten steel surface temperature. Regardless of the type, the measurement accuracy is stable and improved.
尚、多周波渦流センサー１１としては差分方式のセンサーもあるが、多周波渦流式である限り本発明を適用することができる。 The multi-frequency eddy current sensor 11 includes a differential sensor, but the present invention can be applied as long as it is a multi-frequency eddy current sensor.
１ 鋳型銅板
２ 溶鋼
２ａ 溶鋼湯面位置
３ 凝固シェル
４ モールドパウダー
５ 溶融層
６ 粉末層
７ 架台
８ 保持台
９ 支持台
１０ 保持具
１１ 多周波渦流センサー
１２ ケース
１３ 励磁コイル
１４ 検出コイル
１５ 発振器
１６ 電源アンプ
１７ 差動アンプ
１８ ロックインアンプ
DESCRIPTION OF SYMBOLS 1 Mold copper plate 2 Molten steel 2a Molten steel surface position 3 Solidified shell 4 Mold powder 5 Molten layer 6 Powder layer 7 Mounting stand 8 Holding stand 9 Supporting stand 10 Holding tool 11 Multifrequency eddy current sensor 12 Case 13 Excitation coil 14 Detection coil 15 Oscillator 16 Power supply Amplifier 17 Differential amplifier 18 Lock-in amplifier
Claims (3)
前記位相情報と絶対値情報とを得るための計測データ収集工程と、
該計測データ収集工程にて収集した前記位相情報と前記絶対値情報の各データを
銅板間隔に対して補正する第一の補正工程と、
前記第一の補正工程で補正された前記位相情報と前記絶対値情報の各データを
前記モールドパウダーの溶融層内の渦電流密度分布に基づいて補正する第二の補正工程と、
該第二の補正工程にて補正した前記位相情報と前記絶対値情報の各データに基づいて、モールドパウダーの溶融層の厚みを演算する演算工程と、
を有することを特徴とする多周波渦流式モールドパウダー溶融厚み計測方法。 A multi-frequency eddy current mold powder melt thickness measurement method for measuring the thickness of a molten layer of mold powder added on a molten metal in a continuous casting mold using phase information and absolute value information at at least two frequencies. Because
A measurement data collection step for obtaining the phase information and absolute value information;
Each data of the phase information and the absolute value information collected in the measurement data collecting step
A first correction step for correcting the copper plate spacing ;
Each data of the phase information and the absolute value information corrected in the first correction step
A second correction step for correcting based on the eddy current density distribution in the molten layer of the mold powder;
A calculation step of calculating the thickness of the molten layer of the mold powder based on each data of the phase information and the absolute value information corrected in the second correction step,
A multi-frequency eddy current mold powder melt thickness measuring method characterized by comprising:
前記位相情報と絶対値情報とを得るための計測データ収集工程と、
該計測データ収集工程にて収集した前記位相情報と前記絶対値情報の各データを
前記モールドパウダーの溶融層内の渦電流密度分布に基づいて補正する第一の補正工程と、
前記第一の補正工程で補正された前記位相情報と前記絶対値情報の各データを
銅板間隔に対して補正する第二の補正工程と、
該第二の補正工程にて補正した前記位相情報と前記絶対値情報の各データに基づいて、モールドパウダーの溶融層の厚みを演算する演算工程と、
を有することを特徴とする多周波渦流式モールドパウダー溶融厚み計測方法。 A multi-frequency eddy current mold powder melt thickness measurement method for measuring the thickness of a molten layer of mold powder added on a molten metal in a continuous casting mold using phase information and absolute value information at at least two frequencies. Because
A measurement data collection step for obtaining the phase information and absolute value information;
Each data of the phase information and the absolute value information collected in the measurement data collecting step
A first correction step for correcting based on the eddy current density distribution in the molten layer of the mold powder ;
Each data of the phase information and the absolute value information corrected in the first correction step
A second correction step for correcting the copper plate interval;
A calculation step of calculating the thickness of the molten layer of the mold powder based on each data of the phase information and the absolute value information corrected in the second correction step,
A multi-frequency eddy current mold powder melt thickness measuring method characterized by comprising:
前記渦電流密度分布を、
モールドパウダー種類に対応して該モールドパウダーの導電率温度依存データと溶融層層内の厚み方向温度分布から求めることを特徴とする多周波渦流式モールドパウダー溶融厚み計測方法。 In the multi-frequency eddy current mold powder melt thickness measuring method according to claim 1 or 2 ,
The eddy current density distribution is
A multi-frequency eddy current mold powder melt thickness measuring method characterized in that it is obtained from the conductivity temperature dependence data of the mold powder and the thickness direction temperature distribution in the melt layer corresponding to the mold powder type .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005206536A JP4752366B2 (en) | 2005-07-15 | 2005-07-15 | Multi-frequency eddy current mold powder melt thickness measurement method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2005206536A JP4752366B2 (en) | 2005-07-15 | 2005-07-15 | Multi-frequency eddy current mold powder melt thickness measurement method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2007021529A JP2007021529A (en) | 2007-02-01 |
| JP4752366B2 true JP4752366B2 (en) | 2011-08-17 |
Family
ID=37782958
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2005206536A Expired - Fee Related JP4752366B2 (en) | 2005-07-15 | 2005-07-15 | Multi-frequency eddy current mold powder melt thickness measurement method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4752366B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5073698B2 (en) * | 2009-03-09 | 2012-11-14 | 新日本製鐵株式会社 | Method for continuous casting of molten metal |
| JP5782202B1 (en) | 2014-08-01 | 2015-09-24 | 株式会社ニレコ | Eddy current mold level measuring apparatus and mold level measuring method |
| WO2016017028A1 (en) * | 2014-08-01 | 2016-02-04 | 株式会社ニレコ | Eddy current-type mold level measurement device and mold level measurement method |
| CN107167516B (en) * | 2017-05-24 | 2023-09-26 | 昆明理工大学 | Double differential pulse eddy current probe unit, array probe and detection device |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0318462A (en) * | 1989-06-16 | 1991-01-28 | Kawasaki Steel Corp | Method and instrument for measuring molten layer thickness of mold powder on molten steel surface in mold for continuous casting |
| JP3230513B2 (en) * | 1999-03-03 | 2001-11-19 | 日本鋼管株式会社 | Method of estimating molten steel flow velocity in continuous casting mold, quality control method in continuous casting of steel, and continuous casting method of steel |
-
2005
- 2005-07-15 JP JP2005206536A patent/JP4752366B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2007021529A (en) | 2007-02-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4752366B2 (en) | Multi-frequency eddy current mold powder melt thickness measurement method | |
| CN102661966B (en) | Method and device for measuring linear shrinkage rate and thermal stress of metal solidification process | |
| JP4765517B2 (en) | Automatic mold powder feeder for continuous casting | |
| EP3183521A1 (en) | A system and a method for determining temperature of a metal melt in an electric arc furnace | |
| CN109550906A (en) | The measuring device and its measurement method of molten steel flow velocity in a kind of continuous cast mold | |
| JP5690230B2 (en) | Method for measuring molten layer thickness of mold powder for continuous casting | |
| JP2006205227A (en) | Method and apparatus for calibrating multi-frequency vortex type thickness measuring instrument of molten mold powder | |
| CN113084102B (en) | Crystallizer protection slag liquid slag layer thickness testing device and method based on wettability | |
| Heugenhauser et al. | Density and thermal expansion of the nickel-based superalloy INCONEL 625 in the solid and liquid states. | |
| EP1709453B1 (en) | Method to forecast the electrical conductivity of anodes for aluminum production before baking | |
| JP2007098400A (en) | Continuous casting apparatus and method for measuring flowing rate | |
| US3891512A (en) | Determination of oxygen in molten steel | |
| JP3672632B2 (en) | Consumable probe for simultaneous measurement of molten slag temperature and electrical conductivity, and method for simultaneous measurement of molten slag temperature and electrical conductivity | |
| CN111044563A (en) | Method for rapidly testing heat transfer performance of high-temperature inorganic nonmetallic material based on hot wire method | |
| JP2005125402A (en) | Method for continuously casting cast block, and method for judging quality of cast block | |
| CN113172207B (en) | Device for measuring surface flow field of molten steel in crystallizer based on current change | |
| JPH0194201A (en) | Method and apparatus for measuring thickness of molten slag | |
| JPH0833360B2 (en) | Method for determining crystallization temperature of high temperature melt | |
| Terekhin et al. | Eddy current method for steel billet mould level control | |
| KR20190137265A (en) | Solidification simulator | |
| JP5915589B2 (en) | Temperature measurement method for continuous casting mold | |
| JP2019126834A (en) | Apparatus and method for equipment monitoring and program | |
| JP2010099697A (en) | Continuous casting method for molten steel | |
| Krasilnikov et al. | Local heat transfer through mold flux film and optimal narrow face taper adjustment | |
| JP2007289977A (en) | Method and instrument for estimating molten metal temperature in mold for continuous casting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080423 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100728 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20101026 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20101222 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20110426 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20110509 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140603 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4752366 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |