JPH0321867A - Method and apparatus for analyzing gaseous component in metal - Google Patents

Abstract

PURPOSE:To make exact analysis with less fluctuations by placing an analysis sample of metal into a high-frequency coil, energizing the high-frequency coil to suspend the sample in air and continuing the energization to heat and dissolve the sample. CONSTITUTION:The gas from a gas source 5 is passed in a dissolving and extracting chamber C2 and a preliminary chamber C1 to form an inert gaseous atmosphere. A shutter S2 is opened and a cylinder L1 is actuated to advance a receiving tray P1 into the extracting chamber C2. The tray P1 is rotated 180 deg. by the revolution of a motor M to drop the sample 7a into a container P2. The tray P1 is reset and the shutter S2 is closed. The sample 7a is suspended in the extracting chamber C2 by electromagnetic induction when the container P2 is risen by actuating a cylinder L2. The temp. of the sample 7a increases and the sample dissolves when the energization is continued and, therefore, the released gas is exctracted by the inert carrier gas and the quantity thereof is measured by a determining device 6. The inert gas is then passed to cool the suspended sample 7b. The sample 7b falls into the container P2 when the high-frequency electric power is interrupted.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for analyzing gas components in metals using floating dissolution technology, and an apparatus used to carry out the analysis method. [Prior Art] The characteristics of special steel and titanium alloy are greatly affected by trace amounts of gas components such as nitrogen, hydrogen, oxygen, or argon contained therein. Accurately quantifying trace amounts of these components is an important issue for process control, product quality evaluation, and research and development. Conventional analytical methods rely on heating and dissolving the sample in vacuum or in an inert gas atmosphere, and quantifying the released gas using a method appropriate for each gas.
Heating methods include high-frequency induction, electrical resistance, and impulse heating, and quantitative methods include gas volumetric method, electrom titration method, and infrared 1! There are methods such as A@accumulation method and thermal conductivity method. The most typical is a combination of impulse heating in an inert gas and infrared absorption or thermal conductivity methods. Regardless of which method is used, the current situation is that the sample is placed in a graphite crucible and heated and melted. The amount of nitrogen, hydrogen, argon, etc. contained in the sample is
It is calculated by subtracting the blank value of the graphite crucible from the measured value, and it goes without saying that as the measured value decreases, the blank value becomes relatively large and its influence increases. Demands for the performance of metal materials are increasing, and improvements in scouring technology have made it possible to quantify the amount of sulfur contained in metal materials. Taking the analysis of hydrogen as an example, the content is 11pp.
It is necessary to quantify what is inside and outside m, while the blank value is o. It reaches 2ppm. When a graphite crucible is heated and degassed for the purpose of reducing the blank value, even though the gas on the surface can be removed, the graphite crucible becomes susceptible to erosion by the molten metal sample, and as a result, the gas inside the crucible comes out. The blank value does not drop as much as expected. The temperatures that can be reached with conventional analytical methods are about 2000° C. when using high frequency heating and about 300° C. when using impulse heating. High melting point metal such as Ta (melting point approximately 3000℃)
, W (approximately 3410°C). When quantifying nitrogen in Ti or Ti alloys, it is said that most of the nitrogen is in the form of TIN, and its decomposition temperature is approximately Since the temperature is 3000°C, accurate analysis is still difficult with conventional techniques. [Problems to be Solved by the Invention] The purpose of the present invention is to quantify gas components such as nitrogen, hydrogen, oxygen, and argon in metals. In doing so, it is possible to eliminate the influence of blank values originating from graphite crucibles to obtain analytical values with small variations, and it is also possible to easily conduct analyzes targeting high melting point metals and compounds with high decomposition temperatures. It is an object of the present invention to provide an analytical method.It is also an object of the present invention to provide an apparatus for use in carrying out such an analytical method.

[Means to solve the problem]

The analysis method of the present invention is a method for quantitatively analyzing gas components such as nitrogen, hydrogen, oxygen, and argon in metals using floating dissolution technology, in which a metal analysis sample is placed in a high-frequency coil. The sample is suspended in the air by applying electricity, and the sample is dissolved by continuing to apply electricity and heating, and the gas released from the sample is taken out on an inert gas, and the target of analysis in the carrier gas is removed. It consists of quantifying according to each analytical method. As mentioned above, floating melting technology is a technology in which conductive materials such as metals are suspended in the air in an alternating electromagnetic field inside a high-frequency coil, and melted by continuing induction heating in this state, using a crucible etc. This has the advantage that there is no need to worry about contamination from the container. As the carrier gas, a gas selected from ArZ port e and N2, which is different from the component to be analyzed, may be used. Conventionally known techniques may be used to measure the amount of each component extracted by the carrier gas. First, if a substance that interferes with the quantification of the analyte is contained, remove that substance using known means, and then separate the analyte using a column separation method using silica gel or molecular sieves, if necessary. and thermal conductivity method,
Measurement is performed using methods such as infrared absorption method. The analyzer of the present invention is an apparatus for quantitatively analyzing gas components such as nitrogen, hydrogen, oxygen, and argon in metals using floating dissolution technology.
, a floating melting section consisting of a high frequency coil {2} wound on the outside and a sample transport means (3) for positioning the analysis sample in the high frequency electromagnetic field inside the tube, which is connected to a high frequency power source {4}, It combines a gas source (5) for flowing an inert carrier gas into the tube and a quantitative determination device (6) for the gas to be analyzed extracted by the carrier gas. [Function] To show the analysis procedure using the illustrated device, first, the valve (v
1) and (v5) are opened to allow the inert carrier gas from the gas source (5) to flow into the dissolution/extraction chamber (C2), and the air is purged to create an inert gas atmosphere inside the chamber.Next, the shutter is opened. Open (S1), place the analysis sample (7a) on the saucer (P1), close the shutter (S1), and close the valve (
By opening v3) and (v4), the inside of the preliminary chamber (C1) is also maintained in an inert gas atmosphere.Open the valve (v2) and (■6>, and while guiding the gas to the metering device (6>) (V1).(V3),(V
4) Close and (v5) and open the shutter (S2). Operate the cylinder <L1> to advance the saucer (P1) to the position indicated by the dotted line in the lysis/extraction chamber (C2), and turn on the motor (
By rotating the saucer (P1) by 180 degrees by rotating M), the sample (7a) is dropped into the container (P2) waiting at the position indicated by the solid line. After the saucer (P1) is rotated through 180 degrees and moved backward by the operation of the cylinder (L1) to return the saucer, the shutter (S2) is closed. When high-frequency power is supplied from the power supply (4) to the coil (2) and the cylinder (L2) is activated to raise the container (P2) to the position indicated by the dotted line, the analysis sample is moved into the dissolution and extraction chamber (C2) by electromagnetic induction. The cylinder (L2) is activated to return the container (P2) downward. If the electricity is continued, the temperature of the sample will rise and it will melt.
The released gas is extracted with an inert carrier gas and its amount is measured with a meter (6). When the extraction is finished, close the valves (■2) and (v6), open the valves (■1) and (■5) to circulate a large amount of inert gas, and remove the still floating sample (7b). After cooling down sufficiently, remove the cylinder (L).
2) to move the container (P2) upward and stop the supply of high-frequency power, the cooled sample moves into the container (P2).
) to fall. Close the valves (v1) and (v5) and operate the cylinder ([2) to return the container (P2) to its original position. Operate the cylinder (L3) to open the lysis extraction chamber (C2), By moving the container (P2) downwards together with the cylinder {L2}, the analyzed sample can be removed. If the cylinder (L3) is activated and the lysis extraction chamber (C2) is closed, the initial state is restored. The following analysis can be repeated: [Example 1] Determination of nitrogen in pure Ti was carried out by the gas extraction-thermal conductivity method. The dissolution for extraction was carried out using the conventional method by impulse heating of a graphite crucible. The following measurement data were obtained using the present invention: the average value and the standard @ difference σ The reason why the value measured using the conventional technology is low is that, as mentioned above, the nitrogen in li is TiN, and the decomposition is insufficient at the impulse heating temperature of the graphite crucible, so it cannot be completely extracted. [Example 2] Using the apparatus of the present invention shown in the figure, only a blank value for quantitative determination of hydrogen was measured without using a sample.Comparing with the blank value when using a conventional graphite crucible, the following results were obtained. [Effects of the Invention] The present invention applies a technology for dissolving metals suspended in the air to analysis of metals.
Eliminates the need to use graphite crucibles for analysis of gas components such as hydrogen, oxygen, and argon. As a result, it has become possible to obtain accurate analytical values with small variations without being bothered by high blank values derived from graphite crucibles. When using floating melting, it is possible to obtain high temperatures reaching 3,500°C, exceeding the limit of conventional heating melting technology of 3,000°C, making it possible to analyze high-melting point metals such as Ta and W, which was previously difficult. Also, reliable values can now be obtained by the present invention. In general, eliminating the need for a graphite crucible helps reduce analysis costs.

[Brief explanation of drawings]

The drawings show the configuration of the analysis device of the present invention,
It is a detailed cross-sectional view of the dissolution/extraction part, which is the main part, and a system diagram showing the other parts in a simplified manner. 1... Quartz glass tube 2... High frequency coil 3
...Sample transport means 4...High frequency power source 5...
・Inert carrier gas source

Claims (3)

[Claims] (1) Placing a metal analysis sample in a high-frequency coil, energizing the high-frequency coil to suspend the sample in the air, and melting the sample by continuing to energize and heat it;
A method for analyzing gas components in metals, which consists of extracting the gas released from the sample by placing it on an inert carrier gas, and quantifying the target to be analyzed in the carrier gas according to the respective analysis method. (2) The analysis sample is steel, Ti, Ta, W, or an alloy thereof, and the inert carrier gas is Ar, H
2. The method of claim 1, wherein e and N_2 are not analyzed. (3) A floating melting section consisting of a quartz glass tube (1), a high-frequency coil (2) wound around the outside of the tube, and a sample transport means (3) for positioning the analysis sample in the high-frequency electromagnetic field inside the tube. , which is combined with a high frequency power source (4), a gas source (5) for circulating an inert carrier gas in the tube, and a quantitative determination device (6) for the gas to be analyzed extracted by the carrier gas. A device that analyzes components.