JP2001099825A - Method for analyzing oxygen in analysis sample - Google Patents
Method for analyzing oxygen in analysis sampleInfo
- Publication number
- JP2001099825A JP2001099825A JP28120299A JP28120299A JP2001099825A JP 2001099825 A JP2001099825 A JP 2001099825A JP 28120299 A JP28120299 A JP 28120299A JP 28120299 A JP28120299 A JP 28120299A JP 2001099825 A JP2001099825 A JP 2001099825A
- Authority
- JP
- Japan
- Prior art keywords
- oxygen
- gas
- analysis
- flow rate
- sample
- 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.)
- Granted
Links
Landscapes
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
- Sampling And Sample Adjustment (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、金属、耐火物、ス
ラグなどの分析試料中の全酸素量を分析する方法に関す
る。さらに詳しくは、金属などの分析試料中の全酸素量
を迅速かつ正確に測定する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for analyzing the total amount of oxygen in an analysis sample such as a metal, a refractory, and a slag. More specifically, the present invention relates to a method for quickly and accurately measuring the total amount of oxygen in an analysis sample such as a metal.
【０００２】[0002]
【従来の技術】近年、金属、耐火物、スラグなどの分析
試料中の酸素量の迅速かつ正確な分析技術が求められて
いる。2. Description of the Related Art In recent years, a technique for quickly and accurately analyzing the amount of oxygen in an analysis sample such as a metal, a refractory, and a slag has been required.
【０００３】例えば、製鋼分野では、酸化物の形態を制
御した極低酸素鋼や高純度鉄の開発が進められており、
ｐｐｍ（百万分率）レベルの微量の酸素濃度を精度よく
定量することが要求されている。なかでも過酷な条件下
で用いられる軸受鋼では、微量の介在物の中で特にＡｌ
2Ｏ3、ＭｇＯ・Ａｌ2Ｏ3、（Ｃａ，Ｍｇ）Ｏ・Ａｌ2Ｏ3
のような介在物は大きな粒を作りやすく、これらが疲労
破壊の原因となるため、製品中の介在物量の低減と介在
物の形態の制御は重要であり、その前提としてまず製鋼
中の全酸素量を迅速かつ正確に測定する分析技術が望ま
れているのである。[0003] For example, in the steelmaking field, the development of ultra-low oxygen steel and high-purity iron in which the form of oxides is controlled has been advanced.
It is required to accurately quantify the concentration of trace amounts of oxygen at the ppm (parts per million) level. Among bearing steels used under severe conditions, among the trace inclusions, especially Al
2 O 3 , MgO.Al 2 O 3 , (Ca, Mg) O.Al 2 O 3
Inclusions such as can easily form large grains, which can cause fatigue fracture.Therefore, it is important to reduce the amount of inclusions in the product and control the morphology of the inclusions. There is a need for analytical techniques that measure quantities quickly and accurately.
【０００４】分析試料中の全酸素量分析方法としては、
酸素分析装置を用いた次のような方法が提案されてい
る。抽出炉内の分析試料を不活性ガス雰囲気下で加熱融
解して、炭素源と分析試料中の酸素と反応させ、分析試
料中の酸素が炭素源と反応して発生する一酸化炭素ガス
（以下「ＣＯガス」という）を不活性ガス流中に抽出
し、該抽出したＣＯガスを検知器で検出し、ＣＯガス量
から換算して試料中の酸素量を測定するというものであ
る。As a method for analyzing the total amount of oxygen in an analysis sample,
The following method using an oxygen analyzer has been proposed. The analytical sample in the extraction furnace is heated and melted in an inert gas atmosphere, and reacted with a carbon source and oxygen in the analytical sample. "CO gas" is extracted into an inert gas stream, the extracted CO gas is detected by a detector, and the amount of oxygen in the sample is measured by converting from the amount of CO gas.
【０００５】しかし、この方法では、分析試料中の酸素
量が小さい場合、発生する一酸化炭素量が小さいため連
続昇温分析時にガス抽出開始点が不明確となる傾向があ
り、坩堝やガス中に含有される酸素に起因するブランク
値と明確に分離することが困難という点などで不都合で
ある。また、分析試料中の酸素量が大きい場合にはガス
抽出時間が長くなるため分析時間が長くなり、またガス
の抽出完了時点が不明確になる傾向があり、ガス抽出完
了前の段階で測定値を算出してしまい、実際の酸素量よ
りも低い測定値となってしまうことがある。[0005] However, in this method, when the amount of oxygen in the analysis sample is small, the amount of carbon monoxide generated is small, so that the starting point of gas extraction tends to be unclear at the time of continuous temperature rise analysis. This is inconvenient in that it is difficult to clearly separate it from a blank value caused by oxygen contained in oxygen. In addition, when the amount of oxygen in the analysis sample is large, the gas extraction time is long, so the analysis time is long, and the point at which gas extraction is completed tends to be unclear. May be calculated, and the measured value may be lower than the actual oxygen amount.
【０００６】[0006]
【発明が解決しようとする課題】本発明は、上記の問題
点を解決し、より迅速かつ正確に分析試料中の全酸素量
を測定する方法を提供することを課題とする。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for more quickly and accurately measuring the total oxygen content in an analysis sample.
【０００７】[0007]
【課題を解決するための手段】本発明者らは、上記の課
題を解決するために鋭意研究を進めたところ、炭素と試
料中の酸化物由来の酸素とを反応させる際に不活性ガス
の流量を漸次増大させることにより上記の課題を解決で
きることを見出し、本発明を完成させるに至った。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and found that when reacting carbon with oxygen derived from oxides in a sample, an inert gas was used. The inventors have found that the above problem can be solved by gradually increasing the flow rate, and have completed the present invention.
【０００８】すなわち、本発明は、不活性ガスが送入、
排出され不活性ガス雰囲気状態である抽出炉内で、分析
試料を加熱して、抽出炉内の炭素源と分析試料中の酸素
とを反応させ、抽出炉内で生成した一酸化炭素を不活性
ガスの排出とともに抽出炉から排出し、排出された一酸
化炭素から分析試料中の酸素量を求める分析方法であっ
て、前記炭素源と前記酸素との反応開始直後から、前記
不活性ガスの送入、排出流量を所定の最大流量まで漸次
増大させることを特徴とする酸素量分析方法である。That is, according to the present invention, an inert gas is supplied,
In the extraction furnace, which is discharged and in an inert gas atmosphere, the analysis sample is heated, and the carbon source in the extraction furnace reacts with oxygen in the analysis sample to inactivate the carbon monoxide generated in the extraction furnace. An analysis method for obtaining the amount of oxygen in an analysis sample from the carbon monoxide discharged from the extraction furnace together with the discharge of the gas, wherein the supply of the inert gas is started immediately after the reaction between the carbon source and the oxygen is started. An oxygen amount analysis method characterized by gradually increasing the input and output flow rates to a predetermined maximum flow rate.
【０００９】また、本発明は、赤外線吸収法により、前
記排出された一酸化炭素の量を測定して分析試料中の酸
素量を求めることを特徴とする前記酸素量分析方法であ
る。また、本発明は、分析試料が金属試料である前記酸
素量分析方法である。Further, the present invention is the above-mentioned oxygen amount analyzing method, wherein the amount of the discharged carbon monoxide is measured by an infrared absorption method to obtain the amount of oxygen in the analysis sample. Further, the present invention is the above-mentioned oxygen content analysis method, wherein the analysis sample is a metal sample.
【００１０】[0010]
【発明の実施の形態】本発明では、抽出炉内の分析試料
を不活性ガス雰囲気下で加熱して、炭素源と分析試料中
の酸素と反応させ、分析試料中の酸素が炭素源と反応し
て発生するＣＯガスを抽出炉内を流れる不活性ガス流中
に抽出し、抽出したＣＯガスから分析試料中の酸素量を
求める。ＣＯガスから酸素量を求めるには、例えば、抽
出したＣＯガスを赤外線吸収法などによって計測・分析
し、ＣＯガス量を求め、ＣＯガスから試料中の酸素量を
算出する。抽出炉内を不活性ガス雰囲気状態とするた
め、抽出炉には不活性ガスが送入され、また不活性ガス
の送入により、発生したＣＯガスを不活性ガスとともに
抽出炉から押し出して排出する。本発明は、上記のよう
にＣＯガスを搬出する不活性ガスの流量を制御して迅速
かつ正確な分析を行うものである。DETAILED DESCRIPTION OF THE INVENTION In the present invention, an analysis sample in an extraction furnace is heated in an inert gas atmosphere to react with a carbon source and oxygen in the analysis sample, and the oxygen in the analysis sample reacts with the carbon source. The generated CO gas is extracted into an inert gas flow flowing in the extraction furnace, and the amount of oxygen in the analysis sample is determined from the extracted CO gas. In order to obtain the oxygen amount from the CO gas, for example, the extracted CO gas is measured and analyzed by an infrared absorption method or the like, the CO gas amount is obtained, and the oxygen amount in the sample is calculated from the CO gas. In order to make the inside of the extraction furnace an inert gas atmosphere state, an inert gas is fed into the extraction furnace, and by the feeding of the inert gas, the generated CO gas is pushed out of the extraction furnace together with the inert gas and discharged. . The present invention is to perform quick and accurate analysis by controlling the flow rate of the inert gas that carries out the CO gas as described above.
【００１１】なお、不活性ガス雰囲気下の抽出炉内で分
析試料から測定対象となるガスを発生させ、不活性ガス
で抽出炉から搬送して測定対象ガスを赤外線吸収分析装
置で測定する方法のことを不活性ガス搬送−赤外線吸収
法ということがある。A method of generating a gas to be measured from an analysis sample in an extraction furnace under an inert gas atmosphere, transporting the gas from the extraction furnace with an inert gas, and measuring the gas to be measured by an infrared absorption analyzer. This may be referred to as an inert gas transport-infrared absorption method.
【００１２】本発明により分析の対象となる試料として
は、例えば、金属、耐火物、スラグなどが挙げられ、具
体的には好適なものとして鉄鋼材料などが挙げられる。Samples to be analyzed according to the present invention include, for example, metals, refractories, slags and the like, and specific examples thereof include iron and steel materials.
【００１３】炭素源は特に限定されるものではないが、
黒鉛坩堝、黒鉛粉末、黒鉛カプセルや分析試料中に含ま
れる炭素などが炭素源として使用できる。中でも炭素源
として黒鉛坩堝を用い、分析試料を黒鉛坩堝中に投入し
て加熱溶融してＣＯガスを発生させる手段が実用的であ
る。炭素源として黒鉛粉末を用い、分析試料と混合あし
て加熱する方法でも良い。Although the carbon source is not particularly limited,
Carbon contained in graphite crucibles, graphite powder, graphite capsules, and analysis samples can be used as a carbon source. Above all, it is practical to use a graphite crucible as a carbon source, put an analysis sample into the graphite crucible, heat and melt it to generate CO gas. A method may be used in which graphite powder is used as a carbon source, mixed with an analysis sample and heated.
【００１４】不活性ガスの種類としては、好ましくはヘ
リウムガス、アルゴンガスなどが挙げられ、特に好まし
くはヘリウムガスが挙げられる。As the kind of the inert gas, helium gas, argon gas and the like are preferable, and helium gas is particularly preferable.
【００１５】炭素源と分析試料中の酸素とを反応させる
ため分析試料を加熱する。加熱の程度は分析試料の種類
により異なるが、試料中に介在する酸化物を還元分解
し、酸化物由来の酸素と、抽出炉中の炭素源とを反応さ
せることができる温度まで加熱する。例えば、鉄鋼材料
を分析試料とする場合であれば、分析試料を好ましくは
融点以上に加熱し、特に好ましくは２０００〜３０００
℃に加熱する。The sample to be analyzed is heated so that the carbon source reacts with oxygen in the sample to be analyzed. Although the degree of heating varies depending on the type of the analysis sample, the oxide present in the sample is reductively decomposed and heated to a temperature at which oxygen derived from the oxide can react with the carbon source in the extraction furnace. For example, when a steel material is used as the analysis sample, the analysis sample is preferably heated to a temperature equal to or higher than the melting point, and particularly preferably 2000 to 3000.
Heat to ° C.
【００１６】本発明の分析方法では、炭素と試料中の酸
化物由来の酸素とが反応している間に不活性ガスの流量
を制御する。具体的には、炭素源と酸化物由来の酸素と
の反応直後から抽出炉中への不活性ガスの送入流量を増
大させ、抽出炉中のＣＯ分圧を下げる。ＭＯ＋Ｃ→Ｍ＋
ＣＯ（Ｍ：金属、Ｏ：酸素、Ｃ：炭素）という反応中に
ＣＯ分圧を低下させることにより、当該反応は右側への
進行は促進されることになる。また、不活性ガスは抽出
炉外へＣＯガスを搬送するキャリアガスであり、反応中
に不活性ガスの送入流量を増大させること等により、不
活性ガスおよびＣＯガスの抽出炉からの排出速度を増大
させることができる。すなわち、試料中の酸化物由来の
酸素と炭素とが反応している間に不活性ガスの流量を増
大させることで、反応を促進させ、さらにはＣＯガスの
排出時間を短縮できるため、試料の分析時間全体を短縮
することができる。また、反応の促進およびＣＯガスの
排出速度増大により、ガスの抽出開始点を明確化するこ
とができる。また、反応の促進およびＣＯガスの排出速
度増大により、ガスの抽出完了時点を明確化させること
ができ、ＣＯガス抽出完了前の段階で測定値を算出して
しまい、実際の酸素量よりも低い測定値となってしまう
おそれも少ない。In the analysis method of the present invention, the flow rate of the inert gas is controlled while carbon reacts with oxygen derived from the oxide in the sample. Specifically, immediately after the reaction between the carbon source and the oxygen derived from the oxide, the flow rate of the inert gas fed into the extraction furnace is increased, and the CO partial pressure in the extraction furnace is reduced. MO + C → M +
By lowering the CO partial pressure during the reaction of CO (M: metal, O: oxygen, C: carbon), the reaction is promoted to the right. The inert gas is a carrier gas that transports the CO gas to the outside of the extraction furnace. The discharge rate of the inert gas and the CO gas from the extraction furnace is increased by increasing the flow rate of the inert gas during the reaction. Can be increased. That is, by increasing the flow rate of the inert gas while oxygen and carbon derived from the oxide in the sample are reacting, the reaction can be promoted, and the time for discharging the CO gas can be shortened. The overall analysis time can be reduced. Further, by accelerating the reaction and increasing the discharge rate of the CO gas, the starting point of gas extraction can be clarified. Further, by accelerating the reaction and increasing the discharge rate of CO gas, it is possible to clarify the time point at which the gas extraction is completed, and the measured value is calculated at the stage before the completion of CO gas extraction, which is lower than the actual oxygen amount. There is little risk of becoming a measured value.
【００１７】ＣＯガスの生成反応中に不活性ガスの流量
を増大させる際には、不活性ガス流量を反応開始直後か
ら漸次増大させる。漸次増大させるというのは、言い換
えると連続的に滑らかに増大させることである。不活性
ガス流量を一気に増加させると、急激に坩堝が冷却され
てしまい熱効率が悪くなりやすい。また不活性ガス流量
が急激に増大すると、ブランク値が急増するおそれがあ
り、微量酸素を測定する場合にはブランクと測定酸素値
の分離が困難となるおそれがある。When increasing the flow rate of the inert gas during the CO gas generation reaction, the flow rate of the inert gas is gradually increased immediately after the start of the reaction. To increase gradually means, in other words, to increase continuously and smoothly. When the flow rate of the inert gas is increased at a stretch, the crucible is rapidly cooled, and the thermal efficiency tends to deteriorate. Also, if the flow rate of the inert gas increases rapidly, the blank value may increase sharply. In the case of measuring trace oxygen, separation of the blank and the measured oxygen value may be difficult.
【００１８】なお、最初から不活性ガスの流量を多くし
て分析を行うこと、例えば本発明の方法における不活性
ガス流量を増大させた後の最大流量に相当する流量を初
期設定流量としその流量を維持して分析を行うことは、
流量が多いため坩堝の冷却効果が大きく分析試料の加熱
が効率的ではない。It is to be noted that the analysis is carried out by increasing the flow rate of the inert gas from the beginning. For example, the flow rate corresponding to the maximum flow rate after the increase in the flow rate of the inert gas in the method of the present invention is set as the initially set flow rate. Performing the analysis while maintaining
Since the flow rate is large, the cooling effect of the crucible is large and the heating of the analysis sample is not efficient.
【００１９】不活性ガスの流量を増加させ始める時期
は、抽出炉中の炭素源と分析試料に由来する酸素とが反
応を開始した直後であり、例えば、赤外線吸収分析装置
などによりＣＯガス量を測定する場合、波形の現れた時
点を分析装置のモニター上で目視することなどにより判
別することができる。The time when the flow rate of the inert gas is started to increase is immediately after the reaction between the carbon source in the extraction furnace and oxygen derived from the analysis sample is started. For example, the CO gas amount is measured by an infrared absorption analyzer or the like. In the case of measurement, it can be determined by visually observing the time when the waveform appears on a monitor of the analyzer.
【００２０】不活性ガス流量を増加させる前の流量、す
なわち炭素源と酸素とが反応を開始する以前の状態での
不活性ガスの流量は、好ましくは２００〜５００ｍｌ／
ｍｉｎであり、特に好ましくは４００〜５００ｍｌ／ｍ
ｉｎである。The flow rate before increasing the flow rate of the inert gas, that is, the flow rate of the inert gas before the reaction between the carbon source and oxygen starts, is preferably 200 to 500 ml /.
min, particularly preferably 400 to 500 ml / m
in.
【００２１】また、不活性ガスの流量は、所定の最大流
量まで増大させるが、発生したＣＯガスを速く搬送させ
るためにはできるだけ多い流量まで増大させた方が好ま
しい。しかし、試料の種類や分析装置の性能などにもよ
るが、分析精度の観点も考慮すると不活性ガスの最大流
量は、１０００ｍｌ／ｍｉｎを上限とすることが好まし
い。ＣＯガスを抽出する不活性ガス流量が１０００ｍｌ
／ｍｉｎを越えると、ピークを検知する手段によっても
異なるが、発生したＣＯガスが希釈されすぎ、ブランク
との分離がかえって難しくなる場合や、検知したガス量
の値のばらつきが大きくなりやすいからである。The flow rate of the inert gas is increased to a predetermined maximum flow rate, but it is preferable to increase the flow rate as much as possible in order to transport the generated CO gas quickly. However, although it depends on the type of the sample and the performance of the analyzer, the maximum flow rate of the inert gas is preferably set to an upper limit of 1000 ml / min from the viewpoint of analysis accuracy. Inert gas flow for extracting CO gas is 1000ml
If it exceeds / min, it depends on the means for detecting the peak. However, the generated CO gas is too diluted, which makes separation from the blank rather difficult, or the variation in the detected gas amount tends to be large. is there.
【００２２】不活性ガスの流量の増大速度は、ＣＯガス
が発生しピークが検出されている期間全般にわたり、不
活性ガス流量の初期設定値流量から最終的な最大流量ま
で漸次増大させるようにしてもよいし、また、上記のよ
うにあまりに急激に流量を増大させたときに生じ得るブ
ランク値急増などの弊害が発生しなければ、必ずしもピ
ーク検出終了時点まで待たずに所定の最大流量まで不活
性ガス流量を漸次増大させ、その後ピーク検出終了時点
まで最大流量を維持するようにしてもよい。不活性ガス
搬送−赤外線吸収法によりＣＯガス濃度を測定する場合
について具体的に例を上げると次のような方法をとるこ
とができる。例えば、初期設定の不活性ガス流量を４０
０〜５００ｍｌ／ｍｉｎとし、ＣＯガスのピークが検出
され始めた時点からピークの検出が終了する時点まで全
般にわたって徐々に不活性ガスの流量を増大させてい
き、不活性ガスの最大流量は１０００ｍｌ／ｍｉｎ以下
に留めるようにする。あるいは、ピークが検出され始め
た時点からピーク検出終了時点までに要する測定時間の
およそ３分の１程度の時間内で最大ガス流量である１０
００ｍｌ／ｍｉｎまで漸次増大させ、その後ピーク検出
終了時まで１０００ｍｌ／ｍｉｎを維持するという方法
なども採ることもできる。The rate of increase of the flow rate of the inert gas is set so as to gradually increase from the initial set flow rate of the inert gas flow rate to the final maximum flow rate throughout the period in which the CO gas is generated and the peak is detected. Alternatively, if there is no adverse effect such as a sudden increase in blank value that can occur when the flow rate is increased too rapidly as described above, it is not necessary to wait until the peak detection end point, and inactive to a predetermined maximum flow rate. The gas flow rate may be gradually increased, and thereafter, the maximum flow rate may be maintained until the end of the peak detection. The following method can be used to specifically measure the case where the CO gas concentration is measured by the inert gas transport-infrared absorption method. For example, if the initial inert gas flow rate is 40
The flow rate of the inert gas is gradually increased from the time when the peak of the CO gas starts to be detected to the time when the detection of the peak ends, and the maximum flow rate of the inert gas is 1000 ml / min. min or less. Alternatively, the maximum gas flow rate is 10 times within about one third of the measurement time required from the time when the peak detection starts to the time when the peak detection ends.
It is also possible to adopt a method in which the pressure is gradually increased to 00 ml / min and thereafter maintained at 1000 ml / min until the end of the peak detection.
【００２３】なお、ガス流量の増大のさせ方と、ピーク
の検出され始めた時点からピークの検出終了時点までに
要する所要時間との関係は、予めいくつかのパターンに
ついて測定しておくことで、さまざまな種類の分析試料
についての分析作業を容易にすることができる。The relationship between the method of increasing the gas flow rate and the time required from the point at which the peak detection starts to the point at which the peak detection ends is determined in advance by measuring several patterns. Analysis operations for various types of analysis samples can be facilitated.
【００２４】不活性ガス流量制御手段としては、例え
ば、流量計と不活性ガス流量制御弁を用い、任意の流量
調整が可能とするように構成すれば良い。具体的には、
不活性ガス流量は、例えば図１に示される赤外線ＣＯ吸
収検出装置で言えば、図１中の、８、９のガス流量制御
器で流量調整することができる。As the inert gas flow control means, for example, a flow meter and an inert gas flow control valve may be used so that the flow rate can be arbitrarily adjusted. In particular,
For example, in the case of the infrared CO absorption detector shown in FIG. 1, the flow rate of the inert gas can be adjusted by the gas flow controllers 8 and 9 in FIG.
【００２５】さらに本発明者は本発明の方法による分析
を行う場合に、分析試料の溶解量も重要であるという新
しい知見を得た。すなわち、例えば極低酸素量の金属な
どの分析試料や、全酸素量が低く、酸化物の種類が多い
分析試料の場合には、それぞれの酸化物から発生する酸
素量が極少量であるため、酸素の抽出波形が酸素量とは
関係のない装置特有のノイズと重なり、分析試料中の酸
化物から発生した酸素量のみの分離が困難となる傾向が
ある。これを防止するためには、溶解させる分析試料の
量を多くすれば良いが、分析能率と均一溶解の点から、
分析試料の量は０．５〜５ｇとすることが好ましい。Further, the inventor has obtained a new finding that the amount of the sample to be analyzed is also important when performing the analysis according to the method of the present invention. That is, for example, in the case of an analysis sample such as a metal having an extremely low oxygen content, or in the case of an analysis sample having a low total oxygen content and many types of oxides, the amount of oxygen generated from each oxide is extremely small. The extracted waveform of oxygen overlaps with noise peculiar to the apparatus, which is not related to the oxygen amount, and it tends to be difficult to separate only the oxygen amount generated from the oxide in the analysis sample. In order to prevent this, it is sufficient to increase the amount of the analysis sample to be dissolved, but from the viewpoint of analysis efficiency and uniform dissolution,
The amount of the analysis sample is preferably 0.5 to 5 g.
【００２６】発生したＣＯガス量を検知する手段として
は、電量法、導電率法、ガスクロマトグラフ法、赤外線
吸収法、非水溶媒法といった手段を用いることができ、
好ましい方法としては赤外線吸収法などが挙げられる。
検出されたＣＯガス量から酸素量を換算して分析試料中
の酸素量を求めることができる。As means for detecting the amount of generated CO gas, means such as a coulometric method, a conductivity method, a gas chromatograph method, an infrared absorption method, and a non-aqueous solvent method can be used.
Preferred methods include an infrared absorption method.
The amount of oxygen in the analysis sample can be obtained by converting the amount of oxygen from the detected amount of CO gas.
【００２７】図１は本発明の方法に用いることのできる
試料分析装置の要部の構成を概略的に例示したものであ
る。この図において、１は直接通電方式の抽出炉で、そ
の内部には試料を収容する坩堝２を挟持してこれを通電
加熱するための上部電極、下部電極３、４が設けられて
いる。５は交流電源で、その一端は電流計６を介して上
部電極３に接続してあり、他端は下部電極４に接続して
ある。７は両電極３、４間の電圧を測定するための電圧
計である。FIG. 1 schematically illustrates the configuration of a main part of a sample analyzer that can be used in the method of the present invention. In this drawing, reference numeral 1 denotes a direct current type extraction furnace, in which an upper electrode and lower electrodes 3 and 4 for holding a crucible 2 for accommodating a sample and electrically heating the crucible 2 are provided. An AC power supply 5 has one end connected to the upper electrode 3 via the ammeter 6 and the other end connected to the lower electrode 4. Reference numeral 7 denotes a voltmeter for measuring the voltage between the electrodes 3 and 4.
【００２８】１６は本試料分析装置のガス流路であり、
このガス流路には抽出炉１への導入ガスの流量を調整す
る流量制御器８、赤外線ＣＯ吸収検出装置１０へのガス
の流量を調整する流量制御器９が接続してあり、赤外線
ＣＯ吸収検出装置１０で試料中の酸素を分析する。赤外
線ＣＯ吸収検出装置１０の後には、ガス中のＣＯを選択
的に酸化してＣＯ2に変換する常温酸化器１１、この常
温酸化器で生成されたＣＯ2のみを選択的に除去するＣ
Ｏ2除去器１２、ガス中のＨ2Ｏを選択的に除去するＨ2
Ｏ除去器１３を介して熱伝導型分析計１４が接続してあ
り、試料中の窒素を分析するように構成されている。１
７は電気信号制御回路であり、抽出ガス信号を１５のマ
イクロコンピューターに送るとともに、雰囲気ガスのＨ
ｅ量制御の信号を８、９のガス流量制御弁に送る。１５
はマイクロコンピューターなどの演算制御部で試料から
抽出ガス信号を演算処理して、分析試料中の酸素量を定
量する。Reference numeral 16 denotes a gas flow path of the sample analyzer.
A flow controller 8 for adjusting the flow rate of the gas introduced into the extraction furnace 1 and a flow controller 9 for adjusting the flow rate of the gas to the infrared CO absorption detection device 10 are connected to this gas flow path. The oxygen in the sample is analyzed by the detection device 10. After the infrared CO absorption detector 10, the room temperature oxidizer 11 for converting the CO 2 selectively oxidize CO in the gas, to selectively remove only CO 2 generated by the ambient temperature oxidizer C
O 2 remover 12, H 2 for selectively removing of H 2 O in the gas
A thermal conductivity analyzer 14 is connected via an O remover 13 and is configured to analyze nitrogen in a sample. 1
Reference numeral 7 denotes an electric signal control circuit, which sends an extraction gas signal to the microcomputer 15 and controls the atmosphere gas H
e The signal of the amount control is sent to the gas flow control valves 8 and 9. Fifteen
Calculates the amount of oxygen in the analysis sample by arithmetically processing the extracted gas signal from the sample by an arithmetic control unit such as a microcomputer.
【００２９】さらに、図２は、本発明の分析方法に用い
ることができる赤外線ＣＯ吸収検出装置１０の一例を示
したものである。図２に示した赤外線ＣＯ吸収検出装置
１０の参照セル２１には赤外吸収のない窒素などが、検
出器２２には高濃度の被測定成分ガスが満たされてい
る。検出器２２は薄い隔板２３で二つの部屋に仕切られ
ており、この隔板２３につけた金属板がコンデンサー２
４の一極となっている。試料中に被測定成分があると、
それによって吸収された分だけ検出器２２に入る光量が
減少し、検出器２２の両室間に圧力差が生じて隔板２３
が変位し、コンデンサー２４の容量が変化する。この容
量変化を測定して被測定成分の濃度を知ることが出来
る。FIG. 2 shows an example of an infrared CO absorption detector 10 which can be used in the analysis method of the present invention. The reference cell 21 of the infrared CO absorption detection apparatus 10 shown in FIG. 2 is filled with nitrogen or the like having no infrared absorption, and the detector 22 is filled with a high concentration of the component gas to be measured. The detector 22 is divided into two rooms by a thin partition 23, and a metal plate attached to the partition 23
4 is one extreme. If there is a component to be measured in the sample,
As a result, the amount of light entering the detector 22 is reduced by the absorbed amount, and a pressure difference is generated between the two chambers of the detector 22 so that the diaphragm 23
Is displaced, and the capacity of the condenser 24 changes. By measuring this change in capacity, the concentration of the component to be measured can be known.
【００３０】赤外線ＣＯ吸収検出装置１０の感度は参照
セル２１と測定セル２５の光量差に依存する。この光量
差を大きくするには赤外線ＣＯ吸収検出装置の光路長Ｌ
が重要となる。光路長Ｌが５０ｍｍを越えると、赤外光
源２６の強度との組み合わせにもよるが、抽出波形の信
号とノイズの判別が困難になったり、正常な波形が得ら
れなくなる。また、光路長Ｌが短すぎると、参照セル２
１と測定セル２５の光量の差が現れにくくなる。このこ
とから、赤外線ＣＯ吸収検出装置の光路長Ｌは≦５０ｍ
ｍが好ましい。The sensitivity of the infrared CO absorption detector 10 depends on the light quantity difference between the reference cell 21 and the measurement cell 25. To increase the light quantity difference, the optical path length L of the infrared CO absorption detection device
Is important. If the optical path length L exceeds 50 mm, it depends on the combination with the intensity of the infrared light source 26, but it becomes difficult to discriminate the signal of extracted waveform from noise or a normal waveform cannot be obtained. If the optical path length L is too short, the reference cell 2
The difference between 1 and the light quantity of the measurement cell 25 is less likely to appear. From this, the optical path length L of the infrared CO absorption detector is ≦ 50 m
m is preferred.
【００３１】[0031]
【実施例】＜実施例１、比較例１,２＞酸素を全重量中
０．００１％含む鋼材を分析試料とし、赤外線ＣＯ吸収
分析装置を用い、異なる不活性ガス流量条件下で不活性
ガス搬送−赤外線吸収法により酸素量を測定し、測定精
度について比較検討した。実施例１においては、ＣＯガ
スの検知され始めた時点をモニターで確認し、その時点
から１０秒間でガス流量４００ｍｌ／ｍｉｎから８００
ｍｌ／ｍｉｎにまで手動で流量を増大させ、その後は測
定終了時点まで流量を一定とした。比較例１はガス流量
を４００ｍｌ／ｍｉｎ、比較例２は８００ｍｌ／ｍｉｎ
とし、それぞれ一定に維持したまま測定を行った。<Example 1, Comparative Examples 1 and 2> A steel material containing 0.001% of oxygen in the total weight was used as an analysis sample, and an inert gas was used under different inert gas flow conditions using an infrared CO absorption analyzer. The oxygen content was measured by the transfer-infrared absorption method, and the measurement accuracy was compared and examined. In the first embodiment, the time when the detection of the CO gas is started is confirmed on the monitor, and the gas flow rate is changed from 400 ml / min to 800 in 10 seconds from the time.
The flow rate was manually increased to ml / min, and thereafter the flow rate was kept constant until the end of the measurement. Comparative Example 1 had a gas flow rate of 400 ml / min, and Comparative Example 2 had a gas flow rate of 800 ml / min.
The measurement was carried out while keeping each constant.
【００３２】測定には赤外線ＣＯ吸収分析装置を用い、
ガスを搬送する不活性ガスとしてヘリウムを用い、１回
当たりの分析試料の量は１ｇとして、これを黒鉛坩堝内
で２５００℃加熱してＣＯガスを発生させた。試験は、
各ガス流量条件についてそれぞれ３回繰り返した。An infrared CO absorption analyzer was used for the measurement.
Helium was used as an inert gas for carrying the gas, and the amount of the analysis sample per one time was 1 g, and this was heated at 2500 ° C. in a graphite crucible to generate a CO gas. The exam is
Each gas flow condition was repeated three times.
【００３３】ガス流量条件および分析結果を表１に示
す。Table 1 shows gas flow conditions and analysis results.
【００３４】[0034]
【表１】 実施例１の方法は、比較例１に比べて酸素量の測定に要
する時間が短く、また比較例２と比べると分析結果、偏
差などの点から精度がより優れることが明らかになっ
た。[Table 1] It was found that the method of Example 1 requires less time for measuring the amount of oxygen than Comparative Example 1, and that the method is superior to Comparative Example 2 in terms of analysis results, deviation, and the like.
【００３５】＜実施例２,３、比較例３,４＞酸素を全重
量中に酸素を０．００１％含む鋼材と、０．０００５％
含む鋼材について、異なる不活性ガスの流量条件下で、
不活性ガス搬送−赤外線吸収法により酸素量を測定し、
測定精度について比較検討した。<Examples 2 and 3 and Comparative Examples 3 and 4> A steel material containing 0.001% oxygen in the total weight of oxygen and 0.0005%
Containing steel material, under different inert gas flow conditions,
Inert gas transport-measure oxygen content by infrared absorption method,
The measurement accuracy was compared and studied.
【００３６】実施例２、３においては、ＣＯガスが検知
され始めた時点を分析装置のモニターで確認し、１０秒
間でガス流量４００ｍｌ／ｍｉｎから８００ｍｌ／ｍｉ
ｎにまで手動で流量を増大させ、その後は測定終了時点
まで流量を一定とした。比較例３および４ではガス流量
を４００ｍｌ／ｍｉｎとし、一定に維持したまま測定を
行った。その他の条件は、上記「＜実施例１、比較例
１,２＞」と同様とした。In Examples 2 and 3, the point at which the CO gas started to be detected was confirmed on the monitor of the analyzer, and the gas flow rate was changed from 400 ml / min to 800 ml / mi in 10 seconds.
The flow rate was manually increased to n, and thereafter the flow rate was kept constant until the end of the measurement. In Comparative Examples 3 and 4, the gas flow rate was 400 ml / min, and the measurement was performed while maintaining the gas flow rate constant. The other conditions were the same as in the above “<Example 1, Comparative Examples 1, 2>”.
【００３７】ガス流量条件および分析結果を表２に示
す。Table 2 shows gas flow conditions and analysis results.
【００３８】[0038]
【表２】 比較例３、４に比べ、実施例２、３では測定に要する時
間を短くすることができ、しかも分析精度は比較例の場
合と同等レベルを維持することができることが明らかに
なった。[Table 2] Compared with Comparative Examples 3 and 4, it became clear that in Examples 2 and 3, the time required for measurement could be shortened, and that the analysis accuracy could be maintained at the same level as in Comparative Example.
【００３９】[0039]
【発明の効果】本発明によれば、炭素と試料中の酸素と
の反応を促進し、ＣＯガス抽出時間を短縮し、分析時間
を短縮することができる。According to the present invention, the reaction between carbon and oxygen in a sample can be promoted, the CO gas extraction time can be shortened, and the analysis time can be shortened.
【００４０】また、本発明によれば、分析試料中の酸素
の量がごくわずかである場合でも、ガス抽出開始点を
明確化することができる。また、ガスの抽出完了時点も
明確化させることができ、分析試料中の酸素量が多くて
もＣＯガス抽出完了前の段階で測定値を算出してしま
い、実際の酸素量よりも低い測定値となってしまうおそ
れは少ない。Further, according to the present invention, even when the amount of oxygen in the analysis sample is very small, the starting point of gas extraction can be reduced.
Can be clarified. In addition, it is possible to clarify the point at which gas extraction is completed. Even if the amount of oxygen in the analysis sample is large, the measured value is calculated at the stage before the completion of CO gas extraction, and the measured value is lower than the actual amount of oxygen. Is unlikely to be
【図１】本発明の分析方法に用いることができる試料分
析装置の一例を示す装置構造図である。FIG. 1 is an apparatus structural view showing an example of a sample analyzer that can be used in the analysis method of the present invention.
【図２】赤外線ＣＯ吸収検出装置を概略的に示す説明図
である。FIG. 2 is an explanatory view schematically showing an infrared CO absorption detection device.
【図３】実施例１および比較例１による測定結果を示す
図である。（ａ）は比較例１、（ｂ）は実施例１を示
す。FIG. 3 is a diagram showing measurement results according to Example 1 and Comparative Example 1. (A) shows Comparative Example 1, and (b) shows Example 1.
１…直接通電方式の抽出炉 ２…坩堝 ３…上部電極 ４…下部電極 ５…交流電源 ６…電流計 ７…電圧計 ８，９…ガス流量制御弁 １０…赤外線ＣＯ吸収検出装置 １１…常温酸化器 １２…ＣＯ2除去器 １３…Ｈ2Ｏ除去器 １４…熱伝導型分析計 １５…マイクロコンピューター １６…ガス流路 １７…電気信号制御回路 ２１…参照セル ２２…検出器 ２３…隔板 ２４…コンデンサー ２５…試料セル ２６…光源 ２７…凹面鏡 ２８…試料ガス流入口 ２９…試料ガス排出口 ３０…干渉ガスセル ３１…回転セクターDESCRIPTION OF SYMBOLS 1 ... Extraction furnace of a direct electricity type 2 ... Crucible 3 ... Upper electrode 4 ... Lower electrode 5 ... AC power supply 6 ... Ammeter 7 ... Voltmeter 8, 9 ... Gas flow control valve 10 ... Infrared CO absorption detection apparatus 11 ... Room temperature oxidation Device 12: CO 2 remover 13: H 2 O remover 14: Thermal conductivity analyzer 15: Microcomputer 16: Gas flow path 17: Electric signal control circuit 21: Reference cell 22: Detector 23: Separator 24 ... Condenser 25 Sample cell 26 Light source 27 Concave mirror 28 Sample gas inlet 29 Sample gas outlet 30 Interference gas cell 31 Rotating sector
フロントページの続き Ｆターム(参考） 2G042 AA01 BA07 BB04 BB09 CA03 CB06 DA04 EA03 EA05 GA01 GA03 2G055 AA03 BA01 CA25 EA04 EA08 FA02 2G059 AA01 BB08 CC07 DD16 EE01 HH01 LL01 MM01 Continued on front page F term (reference) 2G042 AA01 BA07 BB04 BB09 CA03 CB06 DA04 EA03 EA05 GA01 GA03 2G055 AA03 BA01 CA25 EA04 EA08 FA02 2G059 AA01 BB08 CC07 DD16 EE01 HH01 LL01 MM01
Claims (3)
雰囲気状態である抽出炉内で、分析試料を加熱して、抽
出炉内の炭素源と分析試料中の酸素とを反応させ、抽出
炉内で生成した一酸化炭素を不活性ガスの排出とともに
抽出炉から排出し、排出された一酸化炭素から分析試料
中の酸素量を求める分析方法であって、前記炭素源と前
記酸素との反応開始直後から、前記不活性ガスの送入、
排出流量を所定の最大流量まで漸次増大させることを特
徴とする酸素量分析方法。1. An analysis sample is heated in an extraction furnace in which an inert gas is supplied and discharged and is in an inert gas atmosphere state, so that a carbon source in the extraction furnace reacts with oxygen in the analysis sample, An analysis method for discharging the carbon monoxide generated in the extraction furnace from the extraction furnace together with the discharge of the inert gas, and determining the amount of oxygen in the analysis sample from the discharged carbon monoxide, wherein the carbon source and the oxygen Immediately after the start of the reaction, the introduction of the inert gas,
An oxygen content analysis method characterized by gradually increasing a discharge flow rate to a predetermined maximum flow rate.
酸化炭素の量を測定して分析試料中の酸素量を求めるこ
とを特徴とする請求項１に記載の酸素量分析方法。2. The oxygen amount analysis method according to claim 1, wherein the amount of the discharged carbon monoxide is measured by an infrared absorption method to determine the amount of oxygen in the analysis sample.
たは２に記載の酸素量分析方法。3. The oxygen content analysis method according to claim 1, wherein the analysis sample is a metal sample.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28120299A JP4022347B2 (en) | 1999-10-01 | 1999-10-01 | Analytical oxygen analysis method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28120299A JP4022347B2 (en) | 1999-10-01 | 1999-10-01 | Analytical oxygen analysis method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001099825A true JP2001099825A (en) | 2001-04-13 |
| JP4022347B2 JP4022347B2 (en) | 2007-12-19 |
Family
ID=17635784
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28120299A Expired - Fee Related JP4022347B2 (en) | 1999-10-01 | 1999-10-01 | Analytical oxygen analysis method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4022347B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011056578A (en) * | 2009-09-14 | 2011-03-24 | Sumitomo Metal Ind Ltd | Method for continuously casting molten steel |
| CN103033473A (en) * | 2012-12-20 | 2013-04-10 | 长沙开元仪器股份有限公司 | Element analyzing system |
| JP2013160594A (en) * | 2012-02-03 | 2013-08-19 | Horiba Ltd | Element analyzer |
-
1999
- 1999-10-01 JP JP28120299A patent/JP4022347B2/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011056578A (en) * | 2009-09-14 | 2011-03-24 | Sumitomo Metal Ind Ltd | Method for continuously casting molten steel |
| JP2013160594A (en) * | 2012-02-03 | 2013-08-19 | Horiba Ltd | Element analyzer |
| US9222920B2 (en) | 2012-02-03 | 2015-12-29 | Horiba, Ltd. | Elemental analyzer |
| CN103033473A (en) * | 2012-12-20 | 2013-04-10 | 长沙开元仪器股份有限公司 | Element analyzing system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4022347B2 (en) | 2007-12-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Kim et al. | Thermodynamics of titanium, nitrogen and TiN formation in liquid iron | |
| JP5846344B1 (en) | Method for analyzing nitrogen in metal sample, analyzer for nitrogen in metal sample, method for adjusting nitrogen concentration in molten steel, and method for producing steel | |
| US5795381A (en) | SIO probe for real-time monitoring and control of oxygen during czochralski growth of single crystal silicon | |
| Paek et al. | Nitrogen solubility in high manganese-aluminum alloyed liquid steels | |
| US20020029630A1 (en) | Systems and methods for monitoring or controlling the ratio of hydrogen to water vapor in metal heat treating atmospheres | |
| JP2001099825A (en) | Method for analyzing oxygen in analysis sample | |
| KR100371621B1 (en) | Making of metal products using a gas analyzer | |
| EP0890839B1 (en) | Method for analytically determining oxygen for each form of oxide | |
| JPS61261445A (en) | Treatment of copper converter slag | |
| JP3439974B2 (en) | Method and apparatus for analyzing oxygen or oxide by type of oxide in analysis sample | |
| JP2856006B2 (en) | Trace oxygen analysis method for steel | |
| US3713995A (en) | Method for determining activity of oxygen in liquid and solid metals and alloys | |
| JPS6042644A (en) | Continuous analyzing method of component of molten metal in refining container | |
| JP2001234230A (en) | Method for deciding end point of decarburization refining | |
| JP2001116710A (en) | Method for judging steel refining state | |
| JPH0221547B2 (en) | ||
| JP3198841B2 (en) | Method and apparatus for atomic absorption analysis of suspended particles in gas | |
| JPH01244346A (en) | Monitoring of heat generation process | |
| JPH03131748A (en) | Method for measuring oxygen activity in slag, device thereof and consumption type crucible used for this device | |
| JPH0518962A (en) | Method for analyzing carbon and sulfur contents of metallic sample | |
| SU1206651A1 (en) | Method of analysing material chemical composition | |
| JP3634046B2 (en) | Reduction and recovery method for valuable metals in slag with improved accuracy of molten steel components | |
| JPH1017918A (en) | Guidance method for vacuum decarburizing treatment of molten material | |
| Gomyo et al. | Electrochemical silicon sensor equipped with auxiliary electrode, ZrO2+ ZrSiO4 | |
| JPH0518961A (en) | Method for analyzing nitrogen in metallic sample |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060403 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20070419 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20070424 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070509 |
|
| 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: 20070911 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20071001 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101005 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101005 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111005 Year of fee payment: 4 |
|
| LAPS | Cancellation because of no payment of annual fees |