JPH0829375A - Sensor for measuring quantity of hydrogen dissolved in molten metal - Google Patents
Sensor for measuring quantity of hydrogen dissolved in molten metalInfo
- Publication number
- JPH0829375A JPH0829375A JP6160336A JP16033694A JPH0829375A JP H0829375 A JPH0829375 A JP H0829375A JP 6160336 A JP6160336 A JP 6160336A JP 16033694 A JP16033694 A JP 16033694A JP H0829375 A JPH0829375 A JP H0829375A
- Authority
- JP
- Japan
- Prior art keywords
- solid electrolyte
- molten metal
- electrolyte member
- hydrogen
- sensor
- 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.)
- Pending
Links
Landscapes
- Measuring Oxygen Concentration In Cells (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、プロトン導電性を有す
る固体電解質部材を使用して溶融金属中の水素濃度を測
定する溶融金属中の水素溶解量測定用センサに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for measuring the amount of hydrogen dissolved in molten metal, which uses a solid electrolyte member having proton conductivity to measure the hydrogen concentration in the molten metal.
【0002】[0002]
【従来の技術】従来、溶融金属中の水素濃度を測定する
方法としては、以下に示す方法がある。2. Description of the Related Art Conventionally, there have been the following methods for measuring the hydrogen concentration in molten metal.
【0003】イニシャルバブル法 先ず、溶融金属をサンプリングし、この溶融金属をヒー
ターを内蔵した測定室内に配置する。その後、前記測定
室内を減圧状態にして溶融金属の表面から最初に気泡が
発生したときの測定室内の温度及び圧力から水素量を算
出する。Initial Bubble Method First, molten metal is sampled, and the molten metal is placed in a measuring chamber containing a heater. Then, the amount of hydrogen is calculated from the temperature and pressure inside the measurement chamber when the bubbles are first generated from the surface of the molten metal by reducing the pressure inside the measurement chamber.
【0004】減圧凝固法 サンプリングした溶融金属を減圧下で凝固させ、凝固後
の試料内の気泡の状態観察、標準試料の比重との比較及
び試料断面の気泡の状態から水素ガス量を求める。Decompression solidification method The sampled molten metal is solidified under reduced pressure, the state of bubbles in the sample after solidification is observed, comparison with the specific gravity of the standard sample, and the amount of hydrogen gas is determined from the state of bubbles in the cross section of the sample.
【0005】分圧平衡法 少量の不活性ガスを溶湯に注入しこれを循環させて、水
素ガスが不活性ガス中に拡散し平衡状態になったところ
で前記不活性ガスを回収し、熱伝導度式検出器、ガスク
ロマトグラフ又は質量分析器等で不活性ガス中の水素濃
度を分析し、その分析結果及び溶融金属の温度から溶融
金属中の水素濃度を求める。Partial pressure equilibrium method A small amount of an inert gas is injected into a molten metal and circulated, and when the hydrogen gas diffuses into the inert gas and reaches an equilibrium state, the inert gas is recovered to obtain a thermal conductivity. The hydrogen concentration in the inert gas is analyzed by a gas detector, gas chromatograph, mass spectrometer or the like, and the hydrogen concentration in the molten metal is determined from the analysis result and the temperature of the molten metal.
【0006】真空抽出法 溶融金属をサンプリングし、急冷して凝固させた試料を
真空中で加熱して、試料から放出される水素ガスの量を
熱伝導度式検出器、ガスクロマトグラフ、質量分析器又
は赤外線分析器等を用いて定量する。Vacuum Extraction Method A sample obtained by sampling molten metal, quenching and solidifying is heated in a vacuum, and the amount of hydrogen gas released from the sample is measured by a thermal conductivity type detector, gas chromatograph, mass spectrometer. Alternatively, quantify using an infrared analyzer or the like.
【0007】しかし、これらの従来の溶融金属中の水素
濃度測定方法においては、測定に長時間を要するという
欠点、測定精度が悪いという欠点又は高価な測定装置が
必要であるという欠点等があり、いずれも実際の鋳造現
場での水素溶解量の測定には適していない。However, these conventional methods for measuring the hydrogen concentration in molten metal have the drawbacks that it takes a long time for measurement, that the measurement accuracy is poor, and that expensive measuring devices are required. Neither is suitable for measuring the amount of dissolved hydrogen in actual casting sites.
【0008】これらの問題点を解決すべく開発された測
定方法に、プロトン導電性固体電解質を用いたガス濃淡
電池式の水素センサがある。この種のセンサは、プロト
ン導電性を有する固体電解質からなる部材の一方の面側
に多孔性電極(基準極)及びこの基準極に接触し濃淡電
池の起電力の基準となる基準物質を配設し、他方の面
(測定極)を溶融金属に接触させて、基準極側の水素分
圧と溶融金属中の水素濃度との間の水素活量の差によっ
て生じる起電力から溶融金属中の水素濃度を検出するも
のである。このセンサは、溶融金属中の水素濃度を直接
測定することが可能であり、応答速度が速く、高い精度
を得ることができるという利点を有している。As a measuring method developed to solve these problems, there is a gas concentration battery type hydrogen sensor using a proton conductive solid electrolyte. In this type of sensor, a porous electrode (reference electrode) is provided on one surface side of a member made of a solid electrolyte having proton conductivity, and a reference substance that is in contact with the reference electrode and serves as a reference for electromotive force of a concentration battery is provided. Then, the other surface (measurement electrode) is brought into contact with the molten metal, and the electromotive force generated by the difference in hydrogen activity between the hydrogen partial pressure on the reference electrode side and the hydrogen concentration in the molten metal causes the hydrogen in the molten metal to change. It is to detect the concentration. This sensor has an advantage that it can directly measure the hydrogen concentration in the molten metal, has a high response speed, and can obtain high accuracy.
【0009】[0009]
【発明が解決しようとする課題】しかしながら、上述し
た従来のプロトン導電性固体電解質を用いたセンサは、
溶融金属との接触により固体電解質が還元されて固体電
解質と溶融金属との界面に絶縁性の酸化物膜が形成され
てしまうため、長時間の測定が困難であるという難点が
ある。また、固体電解質と溶融金属との界面に気泡が付
着しやすいため、測定極側の電極反応の分極が大きく、
精度が低下するという欠点もある。However, the sensor using the conventional proton conductive solid electrolyte described above is
Since the solid electrolyte is reduced by contact with the molten metal and an insulating oxide film is formed at the interface between the solid electrolyte and the molten metal, it is difficult to measure for a long time. Further, since bubbles are likely to adhere to the interface between the solid electrolyte and the molten metal, the polarization of the electrode reaction on the measurement electrode side is large,
There is also a drawback that the accuracy decreases.
【0010】固体電解質部材と溶融金属との間にガス室
を設け、溶融金属と固体電解質部材とが直接接触しない
ようにすることも考えられるが、そうすると、溶融金属
が例えば亜鉛合金のように融点が低い場合に、前記ガス
室に酸素ガスが残存すると共に溶融金属中の水素がガス
室に放出されて平衡状態になるまでに長時間を要するた
め、応答速度が低下するという問題点が発生する。It is possible to provide a gas chamber between the solid electrolyte member and the molten metal so that the molten metal and the solid electrolyte member do not come into direct contact with each other. Then, the molten metal has a melting point such as a zinc alloy. In the case of low, the oxygen gas remains in the gas chamber, and it takes a long time for hydrogen in the molten metal to be released into the gas chamber and reach an equilibrium state, which causes a problem that the response speed decreases. .
【0011】本発明はかかる問題点に鑑みてなされたも
のであって、300〜1000℃の温度域で使用可能で
あり、センサと溶融金属との界面に気泡が付着すること
及び絶縁性酸化物膜が形成されることを回避できて、特
に500℃以下の低温域において溶融金属中の水素溶解
量を測定するのに好適の溶融金属中の水素溶解量測定用
センサを提供することを目的とする。The present invention has been made in view of the above problems, and it can be used in a temperature range of 300 to 1000 ° C., bubbles adhere to the interface between the sensor and the molten metal, and an insulating oxide. An object of the present invention is to provide a sensor for measuring the amount of dissolved hydrogen in molten metal, which is capable of avoiding the formation of a film and is particularly suitable for measuring the amount of dissolved hydrogen in molten metal in a low temperature range of 500 ° C. or lower. To do.
【0012】[0012]
【課題を解決するための手段】本発明に係る溶融金属中
の水素溶解量測定用センサは、プロトン導電性を有する
固体電解質材料により形成された固体電解質部材と、こ
の固体電解質部材に設けられた基準極と、この基準極に
対して濃淡電池の起電力の基準を与える基準物質と、前
記固体電解質部材の溶融金属に浸漬される部分に設けら
れた金属膜とを有することを特徴とする。A sensor for measuring the amount of dissolved hydrogen in molten metal according to the present invention is provided with a solid electrolyte member formed of a solid electrolyte material having proton conductivity and provided on the solid electrolyte member. It is characterized by having a reference electrode, a reference substance which gives a reference of electromotive force of the concentration battery to the reference electrode, and a metal film provided in a portion of the solid electrolyte member which is immersed in the molten metal.
【0013】[0013]
【作用】本発明においては、固体電解質部材の溶融金属
に浸漬される部分に金属膜が設けられており、この金属
膜により溶融金属が固体電解質部材に直接接触すること
を防止できる。これにより、固体電解質部材の表面に絶
縁性酸化物膜が形成されることを回避できる。また、こ
の金属膜により、センサに対する溶融金属の濡れ性が向
上し、センサと溶融金属との界面に気泡が付着すること
を回避できる。これにより、低融点金属中の水素溶解量
を迅速且つ高精度で測定することができる。In the present invention, the metal film is provided in the portion of the solid electrolyte member which is immersed in the molten metal, and this metal film can prevent the molten metal from directly contacting the solid electrolyte member. This can prevent the insulating oxide film from being formed on the surface of the solid electrolyte member. Further, this metal film improves the wettability of the molten metal with respect to the sensor, and it is possible to prevent bubbles from adhering to the interface between the sensor and the molten metal. As a result, the amount of hydrogen dissolved in the low melting point metal can be measured quickly and with high accuracy.
【0014】前記金属膜は、白金、ニッケル、亜鉛、
金、銀、クロム、鉄、アルミニウム、パラジウム、ルテ
ニウム、銅、イリジウム、ジルコニウム、チタン、ラン
タン、イットリウム及び希土類金属のうちから選択され
た金属又はこれらの金属の合金からなるものであること
が好ましい。これらの金属又は合金は、固体電解質部材
表面に対する密着性が優れていると共に、低融点合金と
の濡れ性もよいため、固体電解質部材と低融点合金との
濡れ性を改善する効果が大きい。なお、前記金属膜中に
は、溶融金属に対する濡れ性を損なわない範囲で前記金
属以外の金属又は非金属を含有していてもよい。The metal film is formed of platinum, nickel, zinc,
A metal selected from gold, silver, chromium, iron, aluminum, palladium, ruthenium, copper, iridium, zirconium, titanium, lanthanum, yttrium, and a rare earth metal, or an alloy of these metals is preferable. Since these metals or alloys have excellent adhesion to the surface of the solid electrolyte member and also have good wettability with the low melting point alloy, they have a great effect of improving the wettability between the solid electrolyte member and the low melting point alloy. The metal film may contain a metal or a nonmetal other than the metal as long as the wettability with respect to the molten metal is not impaired.
【0015】但し、前記金属膜の厚さが1μm未満であ
ると、濡れ性を改善する効果が十分でない。また、前記
金属膜の厚さが500μmを超えると、固体電解質部材
と金属膜との熱膨張率の差が大きいため、使用時に金属
膜が剥がれやすくなるという問題点が生じる。また、金
属膜の膜厚が厚くなると、水素が固体電解質部材に到達
するのに時間がかかり、応答速度が遅くなるという問題
点も生じる。従って、前記金属膜の厚さは1乃至500
μmであることが好ましい。However, if the thickness of the metal film is less than 1 μm, the effect of improving the wettability is not sufficient. Further, if the thickness of the metal film exceeds 500 μm, there is a large difference in coefficient of thermal expansion between the solid electrolyte member and the metal film, which causes a problem that the metal film is easily peeled off during use. Further, when the metal film becomes thicker, it takes time for hydrogen to reach the solid electrolyte member, resulting in a problem that the response speed becomes slow. Therefore, the thickness of the metal film is 1 to 500.
It is preferably μm.
【0016】[0016]
【実施例】次に、本発明の実施例について、添付の図面
を参照して説明する。図1は本発明の第1の実施例に係
る溶融金属中の水素溶解量測定用センサを示す断面図で
ある。固体電解質部材1は、CaZr0.9In0.1O3-x
(但し、xは0〜0.05)、SrCe0.95Yb0.05O
3-x 及びBaCe0.9Nd0.1O3-x 等のようにプロトン
導電性を有する組成のセラミックス又はガラスにより一
端が閉塞された管状に形成されており、この固体電解質
部材1の内面には例えば、Pt、Ni又は酸化物導電体
等からなる多孔質電極2が焼き付け形成されている。こ
の固体電解質部材1の外面の開放端部近傍の領域を除く
その他の領域には、白金、ニッケル、亜鉛、金、銀、ク
ロム、鉄、アルミニウム、パラジウム、ルテニウム、
銅、イリジウム、ジルコニウム、チタン、ランタン、イ
ットリウム及び希土類金属のうちの1種類以上の金属又
は合金により構成される金属コーティング膜3が1〜5
00μmの厚さで形成されている。この金属コーティン
グ膜3はその組織が緻密なものでもよく、多孔質なもの
でもよいが、金属コーティング膜3の表面には可及的に
滑らかであることが好ましい。また、この金属コーティ
ング膜3は、どのような方法で形成されたものであって
もよく、例えば、ペーストを塗付して焼き付ける方法、
真空蒸着法、CVD(化学気相成長)法、PVD(Phys
ical Vaper Deposition )法、電解めっき法、無電解め
っき法、スパッタリング法、レーザーアブレーション法
及び溶射法等により形成することができる。Embodiments of the present invention will now be described with reference to the accompanying drawings. FIG. 1 is a sectional view showing a sensor for measuring the amount of dissolved hydrogen in molten metal according to the first embodiment of the present invention. The solid electrolyte member 1 is made of CaZr 0.9 In 0.1 O 3-x.
(However, x is 0 to 0.05 ), SrCe 0.95 Yb 0.05 O
It is formed in a tubular shape with one end closed by ceramics or glass having a composition having proton conductivity such as 3-x and BaCe 0.9 Nd 0.1 O 3-x , and the like. A porous electrode 2 made of Pt, Ni, an oxide conductor or the like is formed by baking. Except for the area near the open end of the outer surface of the solid electrolyte member 1, platinum, nickel, zinc, gold, silver, chromium, iron, aluminum, palladium, ruthenium,
1 to 5 metal coating films 3 composed of one or more metals or alloys of copper, iridium, zirconium, titanium, lanthanum, yttrium and rare earth metals
It is formed with a thickness of 00 μm. The metal coating film 3 may have a dense structure or a porous structure, but the surface of the metal coating film 3 is preferably as smooth as possible. Further, the metal coating film 3 may be formed by any method, for example, a method of applying a paste and baking it,
Vacuum deposition method, CVD (chemical vapor deposition) method, PVD (Phys
ical vapor deposition) method, electrolytic plating method, electroless plating method, sputtering method, laser ablation method, thermal spraying method and the like.
【0017】固体電解質部材1の開放端側の端部の外周
面には、セラミックス製パイプ4が嵌合しており、この
パイプ4と固体電解質部材1とは無機接着剤により接合
されている。また、固体電解質部材1とパイプ4との接
合部分は、ガラスシール材6により気密的に封止されて
いる。このガラスシール材6は、その熱膨張係数がセン
サの使用温度域である300乃至1000℃における固
体電解質部材1の熱膨張係数に近く、更に流動点が前記
センサの使用温度以上である緻密質ガラスシール材であ
ることが好ましい。A ceramic pipe 4 is fitted on the outer peripheral surface of the end portion of the solid electrolyte member 1 on the open end side, and the pipe 4 and the solid electrolyte member 1 are joined by an inorganic adhesive. Further, the joint portion between the solid electrolyte member 1 and the pipe 4 is hermetically sealed by the glass sealing material 6. The glass sealing material 6 has a thermal expansion coefficient close to the thermal expansion coefficient of the solid electrolyte member 1 in the temperature range of use of the sensor of 300 to 1000 ° C., and further has a pour point equal to or higher than the use temperature of the sensor. It is preferably a sealing material.
【0018】また、このガラスシール材6は、セラミッ
クスからなるコーティング材7によりコーティングされ
ている。このコーティング材7は、ガラスシール材6と
溶融金属との反応を防ぐためのものである。The glass sealing material 6 is coated with a coating material 7 made of ceramics. The coating material 7 is for preventing the reaction between the glass sealing material 6 and the molten metal.
【0019】セラミックス製パイプ4の内側にはステン
レスからなる金属製パイプ9が挿入されており、この金
属製パイプ9の先端部分は多孔質電極2に接合されてい
る。この金属製パイプ9を介して、固体電解質部材1の
内側に、基準物質として、水素ガス分圧が一定に調整さ
れた基準ガス8を導入する。また、この金属パイプ9
は、多孔質電極2のリードとしても作用する。A metal pipe 9 made of stainless steel is inserted inside the ceramic pipe 4, and a tip portion of the metal pipe 9 is joined to the porous electrode 2. Through this metal pipe 9, a reference gas 8 whose hydrogen gas partial pressure is adjusted to a constant level is introduced as a reference substance into the inside of the solid electrolyte member 1. Also, this metal pipe 9
Also acts as a lead of the porous electrode 2.
【0020】本実施例に係る水素溶解量測定用センサ
は、固体電解質部材1の閉塞端側を溶融金属中に浸漬す
ると共に、金属製パイプ9を介して固体電解質部材1の
内側に基準ガス8として所定濃度の水素又は水蒸気を含
有するガスを供給する。そうすると、固体電解質部材1
の内側の水素分圧と外側の溶融金属中の水素濃度との差
により、固体電解質部材1の内側と外側との間に起電力
が発生する。この起電力を測定することにより、溶融金
属中の水素濃度を測定する。この測定原理は、プロトン
導電性固体電解質物質を用いたガス濃淡電池の起電力を
測定することにより行うものである。In the sensor for measuring the amount of dissolved hydrogen according to this embodiment, the closed end side of the solid electrolyte member 1 is immersed in the molten metal, and the reference gas 8 is introduced inside the solid electrolyte member 1 through the metal pipe 9. A gas containing a predetermined concentration of hydrogen or water vapor is supplied. Then, the solid electrolyte member 1
An electromotive force is generated between the inside and outside of the solid electrolyte member 1 due to the difference between the hydrogen partial pressure inside and the hydrogen concentration in the molten metal outside. The hydrogen concentration in the molten metal is measured by measuring this electromotive force. This measurement principle is performed by measuring the electromotive force of a gas concentration battery using a proton conductive solid electrolyte substance.
【0021】プロトン導電性を示す固体電解質を用いる
ガス濃淡電池式の水素センサは高温で安定に作動し、下
記数式1で与えられる理論値に近い起電力を示す。A gas concentration cell type hydrogen sensor using a solid electrolyte exhibiting proton conductivity operates stably at high temperatures and exhibits an electromotive force close to the theoretical value given by the following mathematical formula 1.
【0022】[0022]
【数1】 E=(RT/2F)ln[PH1(1)/PH2(2)] 但し、Eは起電力(V)、Rは気体定数、Fはファラデ
ー定数、Tは絶対温度、PH1(1)及びPH2(2)は夫
々測定極側及び基準極側の水素分圧である。## EQU1 ## E = (RT / 2F) ln [P H1 (1) / P H2 (2)] where E is electromotive force (V), R is gas constant, F is Faraday constant, T is absolute temperature, P H1 (1) and P H2 (2) are hydrogen partial pressures on the measurement electrode side and the reference electrode side, respectively.
【0023】溶融金属中の水素濃度とその溶湯上の水素
分圧との間には平衡関係が成り立ち、下記数式2のシー
ベルトの(Sieverts)の規則に従う。There is an equilibrium relationship between the hydrogen concentration in the molten metal and the hydrogen partial pressure on the molten metal, which follows the Sieverts rule of the following mathematical formula 2.
【0024】[0024]
【数2】S=K(PH2)1/2 但し、Sは水素の平衡溶解度、Kは定数、PH2は溶湯上
の水素分圧である。## EQU2 ## S = K (P H2 ) 1/2 where S is the equilibrium solubility of hydrogen, K is a constant, and P H2 is the partial pressure of hydrogen on the melt.
【0025】この数式2からわかるように、溶湯に接し
た気相中の水素分圧を測定できれば、溶湯中に溶解して
いる水素濃度を求めることができる。As can be seen from the equation (2), if the hydrogen partial pressure in the vapor phase in contact with the molten metal can be measured, the concentration of hydrogen dissolved in the molten metal can be obtained.
【0026】一般的に溶融金属中の水素濃度は、その溶
湯と接した気相中の水素分圧と溶湯温度とに依存し、そ
の水素分圧及び溶湯温度の依存性はシーベルト則とヘン
リー(Henry )則に従う。このため、水素濃度Sは下記
数式3で表すことができる。Generally, the hydrogen concentration in the molten metal depends on the hydrogen partial pressure and the melt temperature in the vapor phase in contact with the melt, and the hydrogen partial pressure and the melt temperature depend on the Sievert's law and Henry's law. Follow the (Henry) rule. For this reason, the hydrogen concentration S can be expressed by the following equation (3).
【0027】[0027]
【数3】 logS=A−(B/T)+(1/2)log(PH2) 但し、A及びBは金属の組成に依存した定数である。Equation 3] logS = A- (B / T) + (1/2) log (P H2) where, A and B are constants which depend on the composition of the metal.
【0028】そこで、図1に示すように、一端閉塞型の
固体電解質部材1の外面を溶融金属中に浸漬して、溶湯
中の水素濃度を測定する。即ち、基準極と測定極との間
に発生する起電力から、前記数式1を用いて水素分圧P
H2を求め、この水素分圧を数式3に代入することによ
り、溶湯中の水素濃度Sを求めることができる。Therefore, as shown in FIG. 1, the outer surface of the solid electrolyte member 1 of the one-end closed type is immersed in the molten metal to measure the hydrogen concentration in the molten metal. That is, from the electromotive force generated between the reference electrode and the measurement electrode, the hydrogen partial pressure P
By obtaining H2 and substituting this hydrogen partial pressure into Equation 3, the hydrogen concentration S in the molten metal can be obtained.
【0029】例えば、溶融金属中にカーボンの棒を挿入
して、このカーボンの棒と金属製パイプ9との間の電位
差を測定し、その結果に基づいて溶融金属中の水素溶解
量を検出することができる。For example, a carbon rod is inserted into the molten metal, the potential difference between the carbon rod and the metal pipe 9 is measured, and the amount of hydrogen dissolved in the molten metal is detected based on the result. be able to.
【0030】この場合に、本実施例においては、固体電
解質部材1の外面に金属コーティング膜3が設けられて
おり、溶融金属と固体電解質部材1とが直接接触するこ
とを防止できるので、両者の間に絶縁性酸化物膜が形成
されることを回避できる。また、溶融金属と固体電解質
部材1との間にガス室等を設ける必要がないため、応答
特性が優れている。更に、金属コーティング膜3により
溶融金属に対する濡れ性が向上するため、センサに気泡
が付着することを抑制できる。このため、気泡に起因す
る測定極の電極反応の分極を回避できて測定精度の低下
を回避できる。従って、本実施例に係る水素溶解量測定
用センサによれば、低水素濃度の場合であっても、溶融
金属中の水素溶解量を長時間連続して測定することが可
能であり、測定精度も高い。例えば、従来、亜鉛合金中
の水素濃度は溶解量が極めて少ないために、精度よく分
析することは困難であるとされていた。しかし、本実施
例によれば、亜鉛合金中に溶解した水素濃度の測定も可
能である。また、本実施例に係るセンサは、構造が簡単
であり、起電力を測定するだけで溶湯中の水素溶解量を
測定することができるので、測定装置の小型化が可能で
あり、実際の鋳造工程で使用するのに当たり、操作性が
向上するという利点もある。In this case, in this embodiment, since the metal coating film 3 is provided on the outer surface of the solid electrolyte member 1, direct contact between the molten metal and the solid electrolyte member 1 can be prevented. It is possible to avoid formation of an insulating oxide film between them. Moreover, since it is not necessary to provide a gas chamber or the like between the molten metal and the solid electrolyte member 1, the response characteristics are excellent. Furthermore, since the metal coating film 3 improves the wettability with respect to the molten metal, it is possible to prevent bubbles from adhering to the sensor. Therefore, it is possible to avoid the polarization of the electrode reaction of the measurement electrode due to the bubbles, and avoid the deterioration of the measurement accuracy. Therefore, according to the sensor for measuring hydrogen dissolution amount according to the present embodiment, it is possible to continuously measure the hydrogen dissolution amount in the molten metal for a long time even when the hydrogen concentration is low. Is also high. For example, it has hitherto been considered that it is difficult to perform accurate analysis because the hydrogen concentration in a zinc alloy is extremely small. However, according to this example, the concentration of hydrogen dissolved in the zinc alloy can be measured. In addition, the sensor according to the present embodiment has a simple structure and can measure the amount of hydrogen dissolved in the molten metal only by measuring the electromotive force, so that the measuring device can be downsized and the actual casting There is also an advantage that the operability is improved when it is used in the process.
【0031】図2は本発明の第2の実施例に係る溶融金
属中の水素溶解量測定用センサを示す断面図である。本
実施例が第1の実施例と異なる点は、基準物質として固
体基準物質18を使用した点にあり、その他の構成は基
本的には第1の実施例と同様であるので、同一物には同
一符号を付してその詳しい説明は省略する。FIG. 2 is a sectional view showing a sensor for measuring the amount of dissolved hydrogen in molten metal according to the second embodiment of the present invention. The present embodiment is different from the first embodiment in that a solid reference material 18 is used as the reference material, and other configurations are basically the same as those in the first embodiment. Are denoted by the same reference numerals and detailed description thereof will be omitted.
【0032】固体電解質部材1はプロトン導電性セラミ
ックス又はガラスに形成されており、その内面には多孔
質電極2が形成されている。また、固体電解質部材1の
外面の開放端側の部分を除く領域には、白金、ニッケ
ル、亜鉛、金、銀、クロム、鉄、アルミニウム、パラジ
ウム、ルテニウム、銅、イリジウム、ジルコニウム、チ
タン、ランタン、イットリウム及び希土類金属のうちの
1種類以上から構成される金属又は金属合金からなる金
属コーティング膜3が1〜500μmの厚さで形成され
ている。The solid electrolyte member 1 is formed of proton conductive ceramics or glass, and the porous electrode 2 is formed on the inner surface thereof. Further, platinum, nickel, zinc, gold, silver, chromium, iron, aluminum, palladium, ruthenium, copper, iridium, zirconium, titanium, lanthanum, in a region other than the open end side portion of the outer surface of the solid electrolyte member 1, A metal coating film 3 made of a metal or a metal alloy composed of at least one of yttrium and rare earth metals is formed to a thickness of 1 to 500 μm.
【0033】固体電解質部材1の開放側端部にはセラミ
ックス製パイプ4が嵌合されており、このパイプ4と固
体電解質部材1との接合部分はガラスシール材6により
気密的にシールされ、更にガラスシール材6はセラミッ
クスコーティング材7に被覆されている。A ceramic pipe 4 is fitted to the open end of the solid electrolyte member 1, and a joint portion between the pipe 4 and the solid electrolyte member 1 is hermetically sealed by a glass sealing material 6. The glass sealing material 6 is covered with a ceramic coating material 7.
【0034】固体電解質部材1内には、固体基準物質1
8として、例えば、燐酸アルミニウムと電子導電性酸化
物との混合物又は金属と金属水素化物との混合物等が装
入されている。これらの物質は、水素又は水蒸気活量が
常に維持されるという性質を有している。また、固体電
解質部材1の開放端側にはアルミナセメント11によ
り、封止されている。なお、リード10は、アルミナセ
メント11及び固体基準物質18を挿通して、多孔質電
極2に電気的に接続されている。In the solid electrolyte member 1, the solid reference material 1
As 8, for example, a mixture of aluminum phosphate and electronically conductive oxide, a mixture of metal and metal hydride, or the like is charged. These substances have the property that hydrogen or steam activity is always maintained. Further, the open end side of the solid electrolyte member 1 is sealed with alumina cement 11. The lead 10 is electrically connected to the porous electrode 2 through the alumina cement 11 and the solid reference material 18.
【0035】本実施例においても、第1の実施例と同様
に、低融点溶融金属中の水素濃度を良好な精度で測定す
ることができる。Also in this embodiment, the hydrogen concentration in the low melting point molten metal can be measured with good accuracy, as in the first embodiment.
【0036】以下、本発明の実施例に係る溶融金属中の
水素溶解量測定用センサを実際に製造し、溶融金属中の
水素溶解量と起電力との関係を調べた結果について説明
する。The results of actually manufacturing a sensor for measuring the amount of dissolved hydrogen in molten metal according to the embodiment of the present invention and examining the relationship between the amount of dissolved hydrogen in molten metal and electromotive force will be described below.
【0037】先ず、ペロブスカイト型プロトン導電性酸
化物であるCaZr0.9In0.1O3- x (但し、xは0〜
0.05)により、一端が閉塞した管状の固体電解質部
材を形成した。そして、この固体電解質部材の内側に多
孔質Pt電極を900℃の温度で焼き付けた。その後、
無電解めっきにより、この固体電解質部材の外面にPt
を10μmの厚さに析出させて、金属コーティング膜を
得た。First, CaZr 0.9 In 0.1 O 3 -x (where x is 0 to 0) which is a perovskite type proton conductive oxide.
0.05), a tubular solid electrolyte member having one end closed was formed. Then, a porous Pt electrode was baked inside the solid electrolyte member at a temperature of 900 ° C. afterwards,
By electroless plating, Pt was formed on the outer surface of the solid electrolyte member.
Was deposited to a thickness of 10 μm to obtain a metal coating film.
【0038】次に、この固体電解質部材1をアルミナ製
のパイプ4(外径が6.5mm、内径が4.5mm、長
さが500mm)の先端部にアルミナ質のセラミックス
接着剤を用いて固定し、固体電解質部材1とパイプ4と
の接合部分をガラスシール材6で気密的にシールした。
更に、このガスシール材6をアルミナ質のセラミックス
コーティング材7により被覆した。Next, the solid electrolyte member 1 is fixed to the tip of an alumina pipe 4 (outer diameter 6.5 mm, inner diameter 4.5 mm, length 500 mm) using an alumina ceramic adhesive. Then, the joint portion between the solid electrolyte member 1 and the pipe 4 was hermetically sealed with the glass sealing material 6.
Further, the gas sealing material 6 was covered with an alumina ceramic coating material 7.
【0039】次に、アルミナパイプ4の内側にステンレ
ス製のパイプ9を挿入し、このパイプ9と多孔質電極2
とを接触させて固定した。Next, a stainless steel pipe 9 is inserted inside the alumina pipe 4, and the pipe 9 and the porous electrode 2 are inserted.
And were fixed in contact with.
【0040】このようにして形成した本発明の実施例に
係る2つのセンサ(第1及び第2のセンサ)を、黒鉛る
つぼ内で溶解した温度が400℃の亜鉛合金中に挿入
し、センサの起電力応答を測定した。測定時にはステン
レスパイプ9を介して基準極側に1体積%の水素を含ん
だアルゴンガスを導入した。また、溶融金属中の水素濃
度は、黒鉛るつぼ内で溶解した亜鉛合金上の気相の水素
ガス濃度を変化させることにより調整した。更に、溶融
金属中にカーボン製の棒を挿入し、このカーボン棒と金
属パイプ9との間の電位差を測定することにより、固体
電解質部材の内側と外側との間の起電力測定を行った。
なお、溶融金属中の温度はクロメル−アルメル熱電対
(K熱電対)にて測定した。The two sensors (first and second sensors) according to the embodiment of the present invention thus formed were inserted into a zinc alloy having a temperature of 400 ° C. melted in a graphite crucible, The electromotive force response was measured. At the time of measurement, an argon gas containing 1% by volume of hydrogen was introduced to the reference electrode side through the stainless pipe 9. The hydrogen concentration in the molten metal was adjusted by changing the hydrogen gas concentration in the vapor phase on the zinc alloy melted in the graphite crucible. Further, by inserting a carbon rod into the molten metal and measuring the potential difference between the carbon rod and the metal pipe 9, the electromotive force between the inside and outside of the solid electrolyte member was measured.
The temperature in the molten metal was measured with a chromel-alumel thermocouple (K thermocouple).
【0041】図3は横軸に時間をとり、縦軸に起電力
(EMF)をとって、気相中の水素濃度を変化させたと
きの起電力の変化を示すグラフ図である。また、図4
は、横軸に水素分圧をとり、縦軸に起電力をとって両者
の関係を示すグラフ図である。なお、図4の実線は、ネ
ルンストの式より求められる理論起電力である。また、
図4において△は第1のセンサ、○は第2のセンサを示
す。FIG. 3 is a graph showing changes in electromotive force when the hydrogen concentration in the gas phase is changed, with the horizontal axis representing time and the vertical axis representing electromotive force (EMF). Also, FIG.
FIG. 4 is a graph showing a relationship between the two, with the horizontal axis representing hydrogen partial pressure and the vertical axis representing electromotive force. The solid line in FIG. 4 is the theoretical electromotive force obtained from the Nernst equation. Also,
In FIG. 4, Δ indicates the first sensor and ◯ indicates the second sensor.
【0042】図3に示すように、本実施例に係るセンサ
は、水素濃度変化に対して起電力が迅速に応答した。ま
た、図4に示すように、本実施例に係るセンサは、起電
力と水素濃度との間に良好な相関関係を示し、ネルンス
トの式と極めてよい一致を示した。As shown in FIG. 3, in the sensor according to this example, the electromotive force quickly responded to the change in hydrogen concentration. Further, as shown in FIG. 4, the sensor according to the present example showed a good correlation between the electromotive force and the hydrogen concentration, and showed a very good agreement with the Nernst equation.
【0043】一方、比較のために、金属コーティングが
設けられていない以外は上述の実施例と同様のセンサを
製造し、水素濃度と起電力との関係を調べた。しかし、
このセンサにおいては、起電力が極めて不安定であり、
良好な精度を得ることができないものであった。On the other hand, for comparison, a sensor similar to that of the above-described example was manufactured except that no metal coating was provided, and the relationship between hydrogen concentration and electromotive force was investigated. But,
In this sensor, the electromotive force is extremely unstable,
It was impossible to obtain good accuracy.
【0044】なお、上述の実施例においては、いずれも
固体電解質部材に予めセラミックス製パイプが取り付け
られている場合について説明したが、使用時に固体電解
質部材にセラミックス製パイプを無機接着剤により固定
してもよい。この場合は、固体電解質部材とセラミック
ス製パイプとの接合部を封止するシール材として、その
軟化点がセンサの使用温度以下であり、流動点がセンサ
の使用温度以上の緻密質ガラスシール材を使用すること
が好ましい。In each of the above-described embodiments, the case where the ceramic pipe is attached to the solid electrolyte member in advance has been described, but the ceramic pipe is fixed to the solid electrolyte member by an inorganic adhesive at the time of use. Good. In this case, as a sealing material that seals the joint portion between the solid electrolyte member and the ceramic pipe, a dense glass sealing material having a softening point below the operating temperature of the sensor and a pour point above the operating temperature of the sensor is used. Preference is given to using.
【0045】[0045]
【発明の効果】以上説明したように本発明によれば、固
体電解質部材の溶融金属に浸漬される部分に金属膜が設
けられているため、固体電解質部材と溶融金属とが直接
接触することを防止でき、両者の間に絶縁性酸化物膜が
形成されることを回避できる。また、前記金属膜により
溶融金属に対する濡れ性が向上し、気泡の付着を抑制で
きる。このため、本発明に係る溶融金属中の水素溶解量
測定用センサは、低融点金属の場合であっても応答性の
低下及び測定極側の電極反応の分極を抑制できて、測定
精度が高い。特に、本発明に係る溶融金属中の水素溶解
量測定用センサは、従来困難であるとされていた亜鉛合
金中の水素濃度を高精度で測定することができるという
効果を奏する。As described above, according to the present invention, since the metal film is provided in the portion of the solid electrolyte member which is immersed in the molten metal, it is possible to prevent the solid electrolyte member from directly contacting the molten metal. This can be prevented, and the formation of an insulating oxide film between the two can be avoided. Moreover, the wettability with respect to the molten metal is improved by the metal film, and the adhesion of bubbles can be suppressed. Therefore, the sensor for measuring the amount of dissolved hydrogen in the molten metal according to the present invention can suppress the deterioration of responsiveness and the polarization of the electrode reaction on the measurement electrode side even in the case of a low melting point metal, and the measurement accuracy is high. . In particular, the sensor for measuring the amount of dissolved hydrogen in molten metal according to the present invention has an effect of being able to measure the hydrogen concentration in a zinc alloy, which has been considered difficult in the past, with high accuracy.
【図1】本発明の第1の実施例に係る溶融金属中の水素
溶解量測定用センサを示す断面図である。FIG. 1 is a cross-sectional view showing a sensor for measuring an amount of dissolved hydrogen in molten metal according to a first embodiment of the present invention.
【図2】本発明の第2の実施例に係る溶融金属中の水素
溶解量測定用センサを示す断面図である。FIG. 2 is a sectional view showing a sensor for measuring an amount of dissolved hydrogen in molten metal according to a second embodiment of the present invention.
【図3】実施例のセンサにおける気相中の水素濃度を変
化させたときの起電力の変化を示すグラフ図である。FIG. 3 is a graph showing changes in electromotive force when the hydrogen concentration in the gas phase in the sensor of the example is changed.
【図4】同じくそのセンサにおける水素分圧と起電力と
の関係を示すグラフ図である。FIG. 4 is a graph showing the relationship between hydrogen partial pressure and electromotive force in the same sensor.
1;固体電解質部材 2;多孔質電極 3;金属コーティング膜 4;セラミックス製パイプ 6;ガラスシール材 7;コーティング材 8;基準ガス 9;金属製パイプ 11;アルミナセメント 18;固体基準物質 1; Solid Electrolyte Member 2; Porous Electrode 3; Metal Coating Film 4; Ceramic Pipe 6; Glass Sealing Material 7; Coating Material 8; Reference Gas 9; Metal Pipe 11; Alumina Cement 18; Solid Reference Material
Claims (3)
により形成された固体電解質部材と、この固体電解質部
材に設けられた基準極と、この基準極に対して濃淡電池
の起電力の基準を与える基準物質と、前記固体電解質部
材の溶融金属に浸漬される部分に設けられた金属膜とを
有することを特徴とする溶融金属中の水素溶解量測定用
センサ。1. A solid electrolyte member formed of a solid electrolyte material having proton conductivity, a reference electrode provided on the solid electrolyte member, and a reference for giving a reference of electromotive force of a concentration battery to the reference electrode. A sensor for measuring the amount of hydrogen dissolved in a molten metal, comprising a substance and a metal film provided in a portion of the solid electrolyte member which is immersed in the molten metal.
により一端が閉塞された管状に形成された固体電解質部
材と、この固体電解質部材の内面上に形成された基準極
と、この基準極に対して濃淡電池の起電力の基準を与え
る基準物質と、前記固体電解質部材の外面の溶融金属に
浸漬される部分に設けられた金属膜とを有することを特
徴とする溶融金属中の水素溶解量測定用センサ。2. A solid electrolyte member having a tubular shape, one end of which is closed by a solid electrolyte material having proton conductivity, a reference electrode formed on an inner surface of the solid electrolyte member, and a reference electrode with respect to the reference electrode. For measuring the amount of dissolved hydrogen in a molten metal, comprising a reference substance which gives a reference of electromotive force of a concentration battery, and a metal film provided on a portion of the outer surface of the solid electrolyte member which is immersed in the molten metal. Sensor.
金、銀、クロム、鉄、アルミニウム、パラジウム、ルテ
ニウム、銅、イリジウム、ジルコニウム、チタン、ラン
タン、イットリウム及び希土類金属のうちの少なくとも
1種の金属により構成され、厚さが1乃至500μmで
あることを特徴とする請求項1又は2に記載の溶融金属
中の水素溶解量測定用センサ。3. The metal film comprises platinum, nickel, zinc,
It is composed of at least one metal selected from gold, silver, chromium, iron, aluminum, palladium, ruthenium, copper, iridium, zirconium, titanium, lanthanum, yttrium and rare earth metals, and has a thickness of 1 to 500 μm. The sensor for measuring the amount of hydrogen dissolved in a molten metal according to claim 1 or 2.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6160336A JPH0829375A (en) | 1994-07-12 | 1994-07-12 | Sensor for measuring quantity of hydrogen dissolved in molten metal |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6160336A JPH0829375A (en) | 1994-07-12 | 1994-07-12 | Sensor for measuring quantity of hydrogen dissolved in molten metal |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0829375A true JPH0829375A (en) | 1996-02-02 |
Family
ID=15712778
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP6160336A Pending JPH0829375A (en) | 1994-07-12 | 1994-07-12 | Sensor for measuring quantity of hydrogen dissolved in molten metal |
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JP2000275209A (en) * | 1999-03-26 | 2000-10-06 | Yamari Sangyo Kk | Hydrogen sensor |
US6235417B1 (en) * | 1999-04-30 | 2001-05-22 | Her Majesty The Queen In Right Of Canada, As Represented By The Minister Of Natural Resources | Two-phase hydrogen permeation membrane |
US6457340B1 (en) | 1996-10-07 | 2002-10-01 | Kabushiki Kaisha Kanemitsu | Method of forming a boss of a boss-integrated sheet metal member |
JP2006513403A (en) * | 2002-09-14 | 2006-04-20 | ケンブリッジ ユニバーシティ テクニカル サービシズ リミティド | Hydrogen detection apparatus and method |
US7396443B2 (en) | 2003-02-17 | 2008-07-08 | Dongsub Park | Solid-state electrochemical hydrogen probe for the measurement of hydrogen content in the molten aluminum |
US7488524B2 (en) | 2002-07-31 | 2009-02-10 | Ube Nitto Kasei Co., Ltd. | High-durability photocatalyst film and structure having photocatalytic functions on surface |
WO2009025247A1 (en) | 2007-08-17 | 2009-02-26 | Fujifilm Corporation | Hydrophilic film-forming composition, spray composition, and hydrophilic member using the same |
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1994
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