JPH07234211A - Probe for molten metal laser emission spectral analysis and its analyzing method - Google Patents
Probe for molten metal laser emission spectral analysis and its analyzing methodInfo
- Publication number
- JPH07234211A JPH07234211A JP6326531A JP32653194A JPH07234211A JP H07234211 A JPH07234211 A JP H07234211A JP 6326531 A JP6326531 A JP 6326531A JP 32653194 A JP32653194 A JP 32653194A JP H07234211 A JPH07234211 A JP H07234211A
- Authority
- JP
- Japan
- Prior art keywords
- probe
- molten metal
- opening
- analysis
- inert gas
- 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.)
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- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】溶融金属の成分をオンラインで分
析し、即時に分析結果を得て製造管理に役立てる分析技
術に関する。[Industrial application] The present invention relates to an analytical technique for analyzing molten metal components online and immediately obtaining an analytical result to be useful for manufacturing control.
【０００２】[0002]
【従来の技術】鉄鋼製造業では溶鋼や溶融めっき浴等の
成分を溶融したままの状態で分析し、その結果に基づい
て製造条件を制御する技術が強く求められている。この
要求に対して、溶融金属にスパーク放電やプラズマ放射
或いはレーザー照射などにより励起エネルギを投入し、
励起元素の発光を分光し分析する方法が検討されてい
る。2. Description of the Related Art In the steel manufacturing industry, there is a strong demand for a technique for analyzing components of molten steel, hot dip bath and the like in a molten state and controlling production conditions based on the results. In response to this request, the excitation energy is applied to the molten metal by spark discharge, plasma radiation or laser irradiation,
Methods for spectroscopically analyzing the emission of excited elements have been studied.
【０００３】この方法を実用しようとするとき問題にな
るのは、測定対象の位置が絶えず変動することと悪環境
下での採光技術であり、これらに対しての提案もなされ
ている。[0003] When this method is put to practical use, the problem is that the position of the object to be measured constantly fluctuates and the lighting technique in a bad environment, and proposals have been made for these.
【０００４】例えば、位置の変動に対して、特開昭６１
−１４０８４２号公報には、レーザー光の集光レンズの
焦点距離から５％を超えない範囲に溶融金属表面を位置
させ、励起光を凹面鏡で分光器に導いて分光して測光
し、測定値を平均した後平均値からの隔たりが５％以内
の測定値を再平均して分析値を求める技術が開示されて
いる。又、採光技術として、特開昭５７−１１９２４１
号公報には、励起光をレンズで集光し集光された光を光
ファイバを用いて分光分析器まで伝送する装置が記載さ
れている。For example, Japanese Patent Laid-Open No. Sho 61-61 is concerned with a change in position.
JP-A-140842 discloses that a molten metal surface is positioned within a range not exceeding 5% from a focal length of a condenser lens of laser light, and excitation light is guided to a spectroscope by a concave mirror to perform spectroscopic photometry, and a measured value is measured. A technique is disclosed in which after averaging, measured values within a deviation of 5% from the average value are re-averaged to obtain an analytical value. Further, as a daylighting technique, there is Japanese Patent Laid-Open No. 57-119241.
The publication describes an apparatus that collects excitation light with a lens and transmits the collected light to a spectroscopic analyzer using an optical fiber.
【０００５】[0005]
【発明が解決しようとする課題】溶融金属では表面の位
置の変動の他に、分析精度を阻害する原因として、光学
系の汚染がある。これは、プローブ内で蒸発した成分
が、透過窓やレンズ等の光学系に付着し測定光の強度を
変えるためである。In the molten metal, in addition to the fluctuation of the surface position, contamination of the optical system is a cause of impeding the analysis accuracy. This is because the component evaporated in the probe adheres to the optical system such as the transmission window and the lens and changes the intensity of the measurement light.
【０００６】しかしながら、上記の両者ともに汚染に対
する対策は採られておらず、そのために、分析精度が不
足するという問題があった。However, neither of the above measures has taken measures against contamination, and therefore, there has been a problem that analysis accuracy is insufficient.
【０００７】この問題を解決するためにこの発明は行わ
れたもので、溶融金属の表面の位置変動を可及的に小さ
くすると共に避けられぬ変動に対して対策を講じ、更
に、光学系の汚染を防止することによって高精度分析を
行う技術を提供しようとするものである。The present invention was made in order to solve this problem. The position variation of the surface of the molten metal is made as small as possible and measures are taken against the unavoidable variation. It aims to provide a technique for performing high-precision analysis by preventing contamination.
【０００８】[0008]
【課題を解決するための手段】この目的を達成するため
の手段は、溶融金属表面にレーザー光を照射し発生する
励起光を解析して成分量を求めるレーザー発光分光分析
に用いるプローブであって、上面にレーザー光の透過窓
を下面に溶融金属が出入する開口面を設けるとともに上
方に不活性ガスの導入口を備え、且つ、後端が分光分析
器に接続する石英製の光ファイバをその先端が前記開口
面中央に向き開口面中央との間隔を１０mm以上の範囲に
調整可能に配置した溶融金属のレーザー発光分光分析用
プローブ、及び、このプローブの導入口から、下面の開
口面積１cm2 当たり毎分０．１リットル以上の不活性ガ
スを導入し開口面から排気しながら、前記プローブを溶
融金属に挿入してプローブ内に溶融金属を露出させ、前
記不活性ガスの導入及び排気を保ちながら、パルス半値
幅５００nsec以下のパルスレーザー光を集光点のエネル
ギ密度５０ MW/cm2 以上で開口面中央に集光照射して、
発生する励起光を、その先端を開口面から１０mm以上離
した光ファイバで直接採光して分光分析器に伝送し分光
分析を行う溶融金属のレーザー発光分光分析方法であ
る。A means for achieving this object is a probe used for laser emission spectroscopic analysis in which a molten metal surface is irradiated with laser light to analyze the generated excitation light to determine the amount of components. , A quartz optical fiber having a laser beam transmission window on the upper surface, an opening for letting molten metal in and out on the lower surface, and an inert gas inlet on the upper side, and having a rear end connected to a spectroscopic analyzer. A probe for laser emission spectroscopic analysis of molten metal in which the tip is oriented toward the center of the opening surface and the distance from the center of the opening surface is adjustable within a range of 10 mm or more, and an opening area of the lower surface 1 cm 2 from the inlet of this probe While introducing 0.1 liter or more of an inert gas per minute and evacuating from the opening surface, the probe is inserted into the molten metal to expose the molten metal in the probe, and the inert gas is introduced. While maintaining the fine exhaust, and focused and irradiated on the aperture plane center the following pulsed laser beam pulse half width 500nsec converging point in energy density 50 MW / cm 2 or more,
It is a laser emission spectroscopic analysis method for molten metal in which the generated excitation light is directly collected by an optical fiber whose tip is separated by 10 mm or more from the opening surface and transmitted to a spectroscopic analyzer for spectroscopic analysis.
【０００９】[0009]
【作用】プローブは下面に開口面を有するので、溶融金
属に挿入されたプローブ内には、この開口面から溶融金
属が侵入し、溶融金属が露出した表面が覗いている。こ
の表面（以下、分析面と称す）にプローブ上方の透過窓
を透してレーザー光を照射するが、分析面の化学的変化
を防ぐために、導入口から不活性ガスを導入する。導入
された不活性ガスはその圧力で分析面を押し下げ、開口
面から排出される。不活性ガスの導入を連続して行う
と、分析面の位置は常に開口面近傍に維持される。この
ため、レーザー光の集光点を開口面中心に合わせること
によって、分析面と集光点の位置は良く一致し、エネル
ギ密度の変動が防がれる。Since the probe has the opening surface on the lower surface, the molten metal penetrates through the opening surface into the probe inserted into the molten metal, and the exposed surface of the molten metal is seen. This surface (hereinafter referred to as the analysis surface) is irradiated with laser light through a transmission window above the probe, but an inert gas is introduced from the introduction port in order to prevent chemical change on the analysis surface. The introduced inert gas pushes down the analysis surface by the pressure and is discharged from the opening surface. When the inert gas is continuously introduced, the position of the analysis surface is always maintained near the opening surface. Therefore, by aligning the condensing point of the laser light with the center of the aperture plane, the positions of the analyzing surface and the condensing point are in good agreement, and fluctuations in energy density can be prevented.
【００１０】プローブの上面の透過窓は、下面の開口面
に向けて照射するレーザー光を透し、且つプローブ内を
不活性雰囲気に保つために大気を遮断するためのもので
ある。又、先端を開口面中央に向けた石英製のファイバ
は効率よく採光するためのもので、透過窓とともに光学
系を形成し何れも光の透過度が重視される。しかし、こ
れらの光学系は長い間には蒸気で汚染され透過度が変わ
ってくる。The transmission window on the upper surface of the probe is for transmitting the laser light irradiated toward the opening surface on the lower surface, and for blocking the atmosphere in order to keep the inside of the probe in an inert atmosphere. Further, a fiber made of quartz with its tip facing the center of the opening surface is for efficiently collecting light, and an optical system is formed together with a transmission window, and light transmittance is important in both cases. However, these optical systems are contaminated with vapor for a long time, and the transmittance changes.
【００１１】本発明においては、不活性ガスの導入口を
プローブの上方に設けることにより、不活性ガスの流れ
によって汚染を防いでいる。不活性ガスを上方から下方
に流し続けることによって、分析面からの蒸発物を分析
面に押し戻すことになり透過窓や光ファイバの光学系の
汚染が防止される。In the present invention, the introduction of the inert gas is provided above the probe to prevent contamination by the flow of the inert gas. By continuing to flow the inert gas from the upper side to the lower side, the evaporation material from the analysis surface is pushed back to the analysis surface, and the contamination of the transmission window and the optical system of the optical fiber is prevented.
【００１２】また、この発明では、励起光を光ファイバ
で直接採光しレンズや凹面鏡によって集光しないが、こ
れは、レンズや凹面鏡によってプローブ内を上方から下
方へ流れる不活性ガスの流路が乱されるのを避けるため
である。励起光を集光しなくても光ファイバを開口面に
近づけることによって充分な率で励起光を捉えることが
出来る。しかし、近づけ過ぎると分析面からの蒸発物に
よって汚染されるおそれがあるので、１０mm以上は離す
必要がある。この場合、石英製の光ファイバの開口角は
１１°〜１２°であり、少なくとも直径４mmの範囲で開
口面中央部からの光を捉えることができる。レーザー光
のビーム径は数百μｍで、放電発光の場合のように発光
点が直径数mmの範囲にわたって分布するようなことはな
く、通常照射点が上記の範囲を外れることはない。反対
に、光ファイバ先端を開口面から離し過ぎると入光量が
減少するので、これを考慮し分析対象元素の成分量や検
出器の感度及び必要な精度により間隔を定めるとよい。Further, in the present invention, the excitation light is directly collected by the optical fiber and is not condensed by the lens or the concave mirror, but this is because the flow path of the inert gas flowing from the upper side to the lower side in the probe is disturbed by the lens or the concave mirror. This is to avoid being done. Even if the excitation light is not collected, the excitation light can be captured at a sufficient rate by bringing the optical fiber close to the opening surface. However, if they are too close to each other, they may be contaminated by evaporants from the analysis surface, so it is necessary to separate them by 10 mm or more. In this case, the opening angle of the quartz optical fiber is 11 ° to 12 °, and the light from the central portion of the opening surface can be captured within a range of at least 4 mm in diameter. The beam diameter of the laser light is several hundreds of μm, and the light emitting points are not distributed over a range of several mm in diameter as in the case of discharge light emission, and the irradiation points are usually outside the above range. On the contrary, if the tip of the optical fiber is too far away from the opening surface, the amount of incident light will decrease.
【００１３】不活性ガスをプローブ内の圧が一定になる
ように導入しても、プローブ外側の溶融金属の表面位置
は変動するので、この変動が急激な場合プローブ内の不
活性ガス圧の対応に遅れが生じる。このため、僅かでは
あるが分析面の位置変動が残り、厳密にはこれを避ける
ことはできない。Even if the inert gas is introduced so that the pressure inside the probe becomes constant, the surface position of the molten metal outside the probe fluctuates. Is delayed. For this reason, a slight positional change of the analysis surface remains, which cannot be strictly avoided.
【００１４】レーザー光を集光させている溶融金属の表
面の位置が変動すると、この表面は集光点からずれるの
で、入射されるレーザー光の密度が小さくなる。入射光
の密度が変わると、励起光の強度が変わるだけではな
く、励起光強度の元素間の比が変わるので分析精度が低
下する。When the position of the surface of the molten metal on which the laser light is focused fluctuates, this surface deviates from the focusing point, so that the density of the incident laser light decreases. When the density of the incident light changes, not only the intensity of the excitation light changes but also the ratio of the excitation light intensity between the elements changes, so that the analysis accuracy decreases.
【００１５】この比の変わり方を調べると図２のように
なる。図は、ＺｎにＡｌが混在する溶融金属の表面を集
光点としレーザー発振出力を変えて照射した場合の、Ｚ
ｎの励起光（波長３０３．７５nm）とＡｌの励起光（波
長３０９．２７nm）の強度比についてその変化を示した
ものである。縦軸は検量線作成時の強度比を１としたと
きの両者の強度比、横軸は照射点のエネルギ密度であ
る。エネルギ密度が小さいと強度比の変化が大きいが、
エネルギ密度が５０MW/cm2以上では強度比の変化は小さ
くなる。溶銑の場合のＦｅとＳｉの強度比について、又
溶鋼の場合のＦｅとＳ等についても同じで、溶融金属の
場合上記と同じ傾向を示す。但し、エネルギ密度が大き
くなり過ぎると、励起光の強度測定を妨げるバックグラ
ウンド光の強度が励起光を凌駕して大きくなる。このた
め、エネルギ密度の大きさは１０GW以下にとどめるのが
得策である。Examining how this ratio changes is as shown in FIG. The figure shows Z when irradiation is performed by changing the laser oscillation output with the surface of the molten metal in which Al is mixed in Zn as the converging point.
It shows the change in the intensity ratio between the excitation light of n (wavelength 303.75 nm) and the excitation light of Al (wavelength 309.27 nm). The vertical axis represents the intensity ratio of the two when the intensity ratio when creating the calibration curve is 1, and the horizontal axis represents the energy density at the irradiation point. When the energy density is small, the intensity ratio changes greatly,
When the energy density is 50 MW / cm 2 or more, the change in intensity ratio becomes small. The same applies to the strength ratio of Fe and Si in the case of hot metal, and Fe and S in the case of molten steel, and the same tendency as described above is exhibited in the case of molten metal. However, if the energy density becomes too large, the intensity of the background light, which hinders the measurement of the intensity of the excitation light, becomes greater than that of the excitation light. For this reason, it is a good idea to keep the energy density below 10 GW.
【００１６】又、エネルギ密度を高めるのと同様に、パ
ルスレーザー光の半値幅を小さくすると、パルスのエネ
ルギは変わらなくても短時間に尖頭値の大きなエネルギ
を投入することになり、強度比の変化は小さくなる。沸
点の低い元素と高い元素とがあっても、瞬間的にエネル
ギを投入し一気に高温状態にすることによって、その差
の影響を小さくするものと考えられる。この瞬間の目安
は、パルス半値幅で５００nsec付近である。即ち、パル
ス半値幅を５００nsec以下のパルスレーザー光を照射す
ると、強度比の変化を充分に小さくすることができる。Similarly to increasing the energy density, if the full width at half maximum of the pulsed laser light is reduced, energy with a large peak value is injected in a short time even if the pulse energy does not change, and the intensity ratio The change in is small. Even if there is an element having a low boiling point and an element having a high boiling point, it is considered that the influence of the difference is reduced by instantaneously applying energy and rapidly raising the temperature. The standard at this moment is around 500 nsec in pulse half width. That is, by irradiating a pulsed laser beam having a pulse half width of 500 nsec or less, the change in intensity ratio can be sufficiently reduced.
【００１７】よって、溶融金属の表面位置の僅かな変動
に対処するため、照射するレーザー光のエネルギ密度を
５０MW/cm2以上１０GW以下とし、且つパルス半値幅を５
００nsec以下に分析方法が好ましい。分析面の変動抑制
とエネルギ密度を高めること及びパルス半値幅を制限す
ることは相乗的に作用して励起光の強度比の変動を小さ
く抑えることになる。Therefore, in order to cope with a slight variation in the surface position of the molten metal, the energy density of the laser light to be irradiated is set to 50 MW / cm 2 or more and 10 GW or less, and the pulse half-width is 5 or less.
The analysis method is preferably less than 00 nsec. The suppression of the fluctuation of the analysis surface, the increase of the energy density, and the restriction of the pulse full width at half maximum act synergistically to suppress the fluctuation of the intensity ratio of the excitation light to be small.
【００１８】図３は、蒸気圧の高い溶融亜鉛めっき浴
に、開口面と光ファイバ先端の距離が２０mmのプローブ
を挿入して連続して使用し汚染度合をしらべた結果であ
る。汚染度合の指標としてＺｎの励起光強度を測定し初
期の強度の８０％に低下するまでの時間を調べた。不活
性ガス流量が開口面積１cm2 当たり毎分０．１リットル
で１０時間以上の使用が可能で、流量が増えると汚染量
は急に減少し、毎分０．５では１００日を経ても汚染さ
れない。ただ、１００日以上使用していると、プローブ
先端の変形等により交換を余儀なくされる。溶鋼等の場
合、汚染はもっと軽微である。FIG. 3 shows the results of examining the degree of contamination by inserting a probe having a distance of 20 mm between the opening surface and the tip of the optical fiber into a hot dip galvanizing bath having a high vapor pressure and continuously using the probe. The Zn excitation light intensity was measured as an index of the degree of contamination, and the time until it dropped to 80% of the initial intensity was investigated. With an inert gas flow rate of 0.1 liter per minute per 1 cm 2 of opening area, it can be used for 10 hours or more. When the flow rate increases, the amount of contamination decreases sharply, and at 0.5 per minute, contamination occurs even after 100 days. Not done. However, if it is used for 100 days or more, it will be replaced due to deformation of the probe tip. In the case of molten steel, pollution is much less.
【００１９】よって、分析に際しては、不活性ガス流量
を開口面積１cm2 当たり毎分０．１リットル以上とする
ことが好ましく、０．５リットル以上とすることが、特
に好ましい。Therefore, in the analysis, the flow rate of the inert gas is preferably 0.1 liter per minute or more per 1 cm 2 of opening area, and more preferably 0.5 liter or more.
【００２０】[0020]
実施例１．連続溶融亜鉛めっきラインのめっき槽にプロ
ーブを挿入して、亜鉛めっき浴中のＦｅ及びＡｌを分析
した。分析精度は分析値の相対標準偏差を求めこれによ
って評価した。用いた分析装置を図１に示す。Example 1. The probe was inserted into the plating bath of the continuous hot-dip galvanizing line to analyze Fe and Al in the galvanizing bath. The analysis accuracy was evaluated by calculating the relative standard deviation of the analysis values. The analyzer used is shown in FIG.
【００２１】プローブ１の上方に不活性ガスの導入口２
を設け、下面は開口面３となっている。開口面３は直径
８mmの円形である。An inert gas inlet 2 is provided above the probe 1.
Is provided, and the lower surface is the opening surface 3. The opening surface 3 is circular with a diameter of 8 mm.
【００２２】上面には、石英ガラス製のレーザー光透過
窓４があり、これを通してレーザー光５が照射される。
レーザー光５は照射装置６から発せられるが、ここで
は、発振器からの平行光を反射鏡でその進行方向をプロ
ーブ１の透過窓に向け、更に集光レンズによって開口面
３の中心に焦点を結ぶよう調整して発する。On the upper surface, there is a laser beam transmitting window 4 made of quartz glass, through which laser beam 5 is irradiated.
The laser light 5 is emitted from the irradiation device 6, but here, the parallel light from the oscillator is directed by the reflecting mirror to the transmission window of the probe 1, and further focused by the condenser lens at the center of the aperture surface 3. Adjust and emit.
【００２３】プローブ１の斜め上方から開口面３の中心
に向けて、光ファイバガイド管７を設け、これに光ファ
イバ８を挿し込み開口面３と先端との距離を調整し固定
した。後端は分光分析器９につながる。光ファイバガイ
ド管７はその内径を光ファイバ８の外径に合わせ、その
外側とプローブ壁との間は気密性をもたせるために '
Ｏ' リングでシールした。An optical fiber guide tube 7 was provided from diagonally above the probe 1 toward the center of the opening surface 3, and an optical fiber 8 was inserted into this tube and the distance between the opening surface 3 and the tip was adjusted and fixed. The rear end is connected to the spectroscopic analyzer 9. The optical fiber guide tube 7 has its inner diameter matched with the outer diameter of the optical fiber 8 in order to provide airtightness between the outside and the probe wall.
Sealed with O'ring.
【００２４】導入口２から不活性ガスとしてＡｒガスを
吹き込みながら、プローブ１を溶融金属１０に挿入し分
析を行った。The probe 1 was inserted into the molten metal 10 for analysis while blowing Ar gas as an inert gas from the inlet 2.
【００２５】レーザー発振器には、ＱスイッチＹＡＧレ
ーザーを用い周波数１ｋＨz で発振させた。その他の条
件及び調査結果を表１に示す。As the laser oscillator, a Q-switched YAG laser was used and oscillated at a frequency of 1 kHz. Table 1 shows other conditions and survey results.
【００２６】[0026]
【表１】 [Table 1]
【００２７】発明の実施例では、相対標準偏差は大きな
場合でも、Ａｌで３％台、Ｆｅで５％台と全ての試験で
満足する分析精度が得られた。In the examples of the present invention, even if the relative standard deviation was large, satisfactory analytical precision was obtained in all tests, with Al being in the 3% range and Fe being in the 5% range.
【００２８】これに対して、発明の条件を外れる比較例
では、開口面とファイバ先端のと距離が小さ過ぎた試験
N0. ９、Ａｒガス流量が不足した試験N0. １０、レーザ
ー光のエネルギ密度が不足した試験No. １１及びパルス
半値幅が過大であった試験No. １２では、相対標準偏差
が各々Ａｌ、Ｆｅともに大きく、分析精度は不満足な結
果であった。On the other hand, in the comparative example which deviates from the conditions of the invention, the test in which the distance between the opening surface and the fiber tip is too small.
Relative standard deviations of Al and Fe were N0.9, Test N10 with insufficient Ar gas flow rate, Test No. 11 with insufficient laser beam energy density, and Test No. 12 with excessive pulse half-width. Both were large, and the analysis accuracy was an unsatisfactory result.
【００２９】実施例２． 実施例１．と同様にして、精錬中のステンレス鋼を分析
した。詳細な条件及び調査結果を表２に示す。Example 2. Example 1. The stainless steel during refining was analyzed in the same manner as in. Table 2 shows the detailed conditions and the survey results.
【００３０】[0030]
【表２】 [Table 2]
【００３１】発明の実施例では、相対標準偏差は大きな
場合でも４％を超えず、全ての試験で満足する分析精度
が得られた。In the examples of the invention, even if the relative standard deviation was large, it did not exceed 4%, and satisfactory analytical precision was obtained in all tests.
【００３２】これに対して、発明の条件を外れる比較例
では、開口面とファイバ先端のと距離が小さ過ぎた試験
N0. ９、Ａｒガス流量が不足した試験N0. １０、レーザ
ー光のエネルギ密度が不足した試験No. １１及びパルス
半値幅が過大であった試験No. １２では、相対標準偏差
が大きく、分析精度は不満足な結果であった。On the other hand, in the comparative example outside the conditions of the invention, the test in which the distance between the opening surface and the fiber tip was too small
N0.9, test N10 with insufficient Ar gas flow, test No. 11 with insufficient energy density of laser light, and test No. 12 with excessive pulse half-width had a large relative standard deviation and analytical accuracy. Was an unsatisfactory result.
【００３３】[0033]
【発明の効果】以上述べてきたように、この発明によれ
ば、適当量の不活性ガスがプローブの上方に導入され下
面の開口面から排気されるので、プローブ内の光学系が
蒸気で汚染されることがなく、又溶融亜鉛めっきの分析
面は開口面の位置に保たれる。これに加えて、レーザー
光の照射を適切なエネルギ密度及びパルス半値幅で行う
ので、元素間の強度比が変動せず高い分析精度が得られ
る。As described above, according to the present invention, since an appropriate amount of inert gas is introduced above the probe and exhausted from the opening surface of the lower surface, the optical system in the probe is contaminated with vapor. And the analysis surface of the hot dip galvanizing is kept at the position of the opening surface. In addition to this, since the laser light irradiation is performed with an appropriate energy density and a pulse half-value width, a high analysis precision can be obtained without changing the intensity ratio between elements.
【００３４】このように、製造工程内で直接分析結果を
高い精度で得ることを可能にしたこの発明の製品品質及
び歩留りに及ぼす効果は大きい。As described above, the effect on the product quality and the yield of the present invention, which makes it possible to directly obtain the analysis result with high accuracy in the manufacturing process, is great.
【図１】発明の実施例に用いたプローブの概念図であ
る。FIG. 1 is a conceptual diagram of a probe used in an example of the invention.
【図２】レーザー光のエネルギ密度と励起光の強度比の
変化を示す図である。FIG. 2 is a diagram showing changes in energy density of laser light and intensity ratio of excitation light.
【図３】不活性ガス流量と汚染されずにプローブを継続
使用できる時間との関係を示す図である。FIG. 3 is a diagram showing a relationship between an inert gas flow rate and a time during which a probe can be continuously used without being contaminated.
１ プローブ ２ 導入口 ３ 開口面 ４ 透過窓 ５ レーザー光 ７ 光ファイバガイド管 ８ 光ファイバ ９ 分光分析器 １０ 溶融金属 DESCRIPTION OF SYMBOLS 1 probe 2 introduction port 3 opening surface 4 transmission window 5 laser light 7 optical fiber guide tube 8 optical fiber 9 spectroscopic analyzer 10 molten metal
───────────────────────────────────────────────────── フロントページの続き (72)発明者 坂下 明子 東京都千代田区丸の内一丁目１番２号 日 本鋼管株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akiko Sakashita 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd.
Claims (2)
する励起光を解析して成分量を求めるレーザー発光分光
分析に用いるプローブであって、上面にレーザー光の透
過窓を下面に溶融金属が出入する開口面を設けるととも
に上方に不活性ガスの導入口を備え、且つ、後端が分光
分析器に接続する石英製の光ファイバをその先端が前記
開口面中央に向き開口面中央との間隔を１０mm以上の範
囲に調整可能に配置したことを特徴とする溶融金属のレ
ーザー発光分光分析用プローブ。1. A probe for use in laser emission spectroscopic analysis for analyzing the excitation light generated by irradiating the surface of a molten metal with laser light to determine the amount of components, wherein a transparent window for laser light is provided on the upper surface and molten metal is provided on the lower surface. An optical fiber made of quartz, which has an inlet / outlet opening and an inlet for an inert gas in the upper part, and whose rear end is connected to a spectroscopic analyzer, has its tip facing the center of the opening surface and the distance from the center of the opening surface. A laser emission spectroscopic analysis probe for molten metal, wherein the probe is arranged so as to be adjustable within a range of 10 mm or more.
下面の開口面積１cm 2 当たり毎分０．１リットル以上の
不活性ガスを導入し開口面から排気しながら、前記プロ
ーブを溶融金属に挿入してプローブ内に溶融金属を露出
させ、前記不活性ガスの導入及び排気を保ちながら、パ
ルス半値幅５００nsec以下のパルスレーザー光を集光点
のエネルギ密度５０ MW/cm2 以上１０GW/cm2以下で開口
面中央に集光照射して、発生する励起光を、その先端を
開口面から１０mm以上離した光ファイバで直接採光して
分光分析器に伝送し分光分析を行うことを特徴とする溶
融金属のレーザー発光分光分析方法。2. From the inlet of the probe according to claim 1,
Opening area of the bottom surface 1 cm 2More than 0.1 liters per minute
While introducing an inert gas and exhausting it from the opening,
The probe into the molten metal to expose the molten metal inside the probe
While maintaining the introduction and exhaust of the inert gas,
Focusing point for pulsed laser light with a full width at half maximum of 500 nsec or less
Energy density of 50 MW / cm210 GW / cm or more2Opening in
Concentrate and irradiate the center of the surface to generate excitation light
Directly collect light with an optical fiber that is more than 10 mm away from the opening surface
The solution is characterized by transmitting it to a spectroscopic analyzer for spectroscopic analysis.
Method for laser emission spectroscopy of molten metal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6326531A JPH07234211A (en) | 1993-12-30 | 1994-12-28 | Probe for molten metal laser emission spectral analysis and its analyzing method |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5-355434 | 1993-12-30 | ||
| JP35543493 | 1993-12-30 | ||
| JP6326531A JPH07234211A (en) | 1993-12-30 | 1994-12-28 | Probe for molten metal laser emission spectral analysis and its analyzing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07234211A true JPH07234211A (en) | 1995-09-05 |
Family
ID=26572210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6326531A Pending JPH07234211A (en) | 1993-12-30 | 1994-12-28 | Probe for molten metal laser emission spectral analysis and its analyzing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07234211A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002174631A (en) * | 2000-09-22 | 2002-06-21 | Nkk Corp | Component measuring device for molten metal |
| WO2004001394A3 (en) * | 2002-06-24 | 2004-04-08 | Noranda Inc | Laser induced breakdown spectroscopy for the analysis of molten material |
| KR101406993B1 (en) * | 2012-10-12 | 2014-06-13 | 주식회사 포스코 | Apparatus for componential analysis using laser |
| WO2023176939A1 (en) * | 2022-03-16 | 2023-09-21 | 日本製鉄株式会社 | Laser emission spectrophotometry optical device, laser emission spectrophotometer, laser emission spectrophotometry method, and molten metal plating facility |
| WO2023249048A1 (en) * | 2022-06-21 | 2023-12-28 | 日本製鉄株式会社 | Molten metal bath component analysis system, molten metal bath component analysis method, hot dip galvanizing bath management method, and hot dip galvanized steel sheet manufacturing method |
-
1994
- 1994-12-28 JP JP6326531A patent/JPH07234211A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002174631A (en) * | 2000-09-22 | 2002-06-21 | Nkk Corp | Component measuring device for molten metal |
| WO2004001394A3 (en) * | 2002-06-24 | 2004-04-08 | Noranda Inc | Laser induced breakdown spectroscopy for the analysis of molten material |
| US6909505B2 (en) | 2002-06-24 | 2005-06-21 | National Research Council Of Canada | Method and apparatus for molten material analysis by laser induced breakdown spectroscopy |
| KR101406993B1 (en) * | 2012-10-12 | 2014-06-13 | 주식회사 포스코 | Apparatus for componential analysis using laser |
| WO2023176939A1 (en) * | 2022-03-16 | 2023-09-21 | 日本製鉄株式会社 | Laser emission spectrophotometry optical device, laser emission spectrophotometer, laser emission spectrophotometry method, and molten metal plating facility |
| WO2023249048A1 (en) * | 2022-06-21 | 2023-12-28 | 日本製鉄株式会社 | Molten metal bath component analysis system, molten metal bath component analysis method, hot dip galvanizing bath management method, and hot dip galvanized steel sheet manufacturing method |
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