JPS5931452A - Method and device for determining amount of hydrogen in molten metal - Google Patents

Abstract

PURPOSE:To decrease errors, by sampling molten metal into a part of a sampling vessel which is beforehand evacuated to a vacuum, putting the vessel into a gas capturing vessel which is shielded from the amt. air and breaking the vessel wall in the space formed of the drawing vessel and the solidified metal. CONSTITUTION:When the part of a suction port 10 formed by decreasing the thickness in a part of an internally evacuated drawing vessel 9 is dipped in molten metal, said part is eroded, and molten metal is sucked into the vessel where the molten metal fills the inside of a conduit 11 made of a preliminarily dehydrogenated thin steel plate and arrives at a preliminarily dehydrogenated chiller 12 solidifies by closing vent holes 13. The molten metal is drawn in a part of the vessel 9 and the vessel 9 is put into a gas capturing vessel which is shielded from the atm. air. The vessel wall in the space formed of the vessel 9 and the solidified metal is broken. The amt. of the hydrogen captured in the space and the hydrogen released from the solidified metal are determined, whereby the exact result of the analysis is obtd. with good accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for water evacuation in bath molten metal.

In steel making and aluminum needle making, it is essential to reduce water*stone in the bath molten metal as much as possible in order to improve the mechanical properties of the final product. In order to limit the amount of hydrogen in bath molten metal (hereinafter referred to as molten metal), conventional methods have been to heat the molten metal by IH, or to pump it up with a stone pod, then quench it with water and then boil it. After storing it in Paray ice or liquid nitrogen, cutting it into a predetermined size and polishing it, it is melted in an inert gas and then measured by chromatographic thermal conductivity detection method. It is common to do so.

In some cases, the chaste air heating constant volume ii+1+pressure method is used to determine the MF&.

However, with the above-mentioned constant sampling method, it is difficult to accurately indicate the hydrogen in the molten metal. The reason for this is as shown in Fig. 1, which is an example of iron.When the bath molten metal solidifies, the hydrogen solubility decreases drastically, so a large amount of hydrogen is released, but this released mizuna is It dissipates into the atmosphere and cannot be quantified. The second reason is that after solidification,
Hydrogen is in a supersaturated state at room temperature, so hydrogen becomes a political enemy during analysis preparation work such as sample cutting and IS+ calendaring.

In order to solve this problem of 9511 points, two proposals have been made. Its・i! 】 78 lagoons are sucked up into a 1 meter wide round stainless steel tube completely encapsulated with pure quartz.
Hydrogen released during solidification is absorbed into stainless steel with high hydrogen solubility, and the sample is cut together with the stainless steel cylinder and subjected to quantitative analysis (υZlil et al., Iron and Box 1, 6).
51979.1620). However, when this method is used, a narrow gap is created at the boundary between the solidified metal and the stainless steel cylinder, and water that enters the gap during water cooling decomposes during melting for analysis and generates hydrogen, causing errors. Often,
Furthermore, there is a problem in that the stainless steel (Enkaku) that is pressed in must be completely dehydrogenated beforehand, otherwise the error will become large. As shown in Fig. 2, a container 2 for solidifying steel into a certain rod shape is placed inside a narrow tube 1 made of a thin copper plate, and the tip of the sample collection tube is sealed with a lid. 3 is poured into the molten steel, and after suctioning the molten steel into the container 2, it is slowly cooled to completely release the hydrogen in the molten steel and collected in the vacuum chamber 4, and then as shown in Fig. 3. This is to analyze the hydrogen collected by perforating the Ml steel pipe 1 of the sampling tube 7 in a closed container 6 connected to a gas analyzer 115.
15 July Publication). With this method, the escape of hydrogen released during sample solidification is prevented, and errors due to hydrogen dissipation during cutting and polishing are also prevented, since cutting and polishing the sample is uncomfortable. . However, this proposal still has some drawbacks. That is, it is often experienced that it is not possible to completely recover the hydrogen in the material simply by taking a sample and slowly cooling it. Therefore, it is necessary to completely cut one part of the thin steel tube and heat only this part to quantify the residual hydrogen after the complete hydrogen release during solidification (7). If the hydrogen in the steel of the suction base 8 that does not contribute to the temperature is released from the tip 3 and added, it will cause an error, so it is necessary to take the suction base 8 out of the sealed container 6 and seal it. Molten steel, slag, etc. adhere to the base 8, making the sealing incomplete and hydrogen escaping, resulting in a low value.

The present invention was made in order to solve the problems of the above-mentioned hydrogen kettle method and metering device for molten metal. The hydrogen that had been continuously cut off was placed in a collection container, and the vessel wall of the space formed by the collection container and the solidified remaining end was broken in the collection container, and the hydrogen that had been collected in the space was removed. The present invention also relates to a method and apparatus for regulating hydrogen in molten metal, which is characterized in that the hydrogen released from the solidified metal is fixed.

Hereinafter, the present invention will be explained in detail based on -[flJ of the device of the present invention.

4 and 5 show one embodiment of the collection container of the present invention. In FIG. 4, a part of the collection container 9 with an internal vacuum is made into a thin suction port. When 10 parts are immersed in the molten metal, this part is damaged, and the 6 parts are sucked out, and 2 tubes made of a thin sheet that has been previously dehydrogenated are 1
The inside of the cooling metal 12 is dehydrogenated in advance, and the air hole 13 is closed to solidify. Reference numeral 14 denotes a fixing bolt for fixing the four tubes 11 in a fixed V position inside the collection container 9.

Hydrogen released due to the decrease in hydrogen solubility due to solidification and cooling is released through the vent hole 13 or through the bottom ′′θ1.
1 diffuses and moves at right angles and is collected in the residual space 15. In addition, in FIG. 45, the M discharge fills the middle part of the double cylinder formed by the collection container 9 and the two-plate conduit 11, and the released hydrogen is collected in the remaining space 15. ~λ4 The residual space is the outer periphery of the sample in the collection container shown in FIG. 4, and the inside of the sample is the residual space in the case of the container shown in FIG. In the former case, immediately after collecting the sample, place the latter in a collection container as shown in Figure 6.
The 7th cup is placed in a 'container', an example of which is shown in Figure 7. In FIG. 6, the sample is inserted into the collection container 16 together with the collection container 9, and the lid 17 is sealed. After the atmosphere inside the collection container 16 is replaced with a carrier force or evacuated to vacuum as necessary, the stainless steel bellows 18 welded to the collection container 16 is driven by an external screw 19, and the II L bellows is removed. The blade 20 provided inside the container 18 is pressed against the collection container 9 supported by the supporter 21 to break it, and the remaining space shown in FIG. . In FIG. 7 as well, the wall of the residual space created in the collection container 9 by the operation 4)R is broken by the blade 2o,
The hydrogen in the residual space is released into the collection vessel. The released hydrogen as well as the i released from the sample over time.
The hydrogen is transported by carrier gas by opening and closing the valve at regular intervals, and the interview 'Igh' analysis H; do. In Figures 4 and 5, the collection container 9 may be made of inorganic material such as quartz or ceramics, or metal such as steel plate.
(It is required that the material can be easily converted into a gamma container in one hour, while the other parts must have a certain degree of heat resistance so as not to undergo changes such as melting and loss during collection, and be made of an airtight material. In addition, although we have shown examples of products made of thin steel sheets as exclusive products,
, Cu and other metals,
It is possible to use highly breathable refractories such as vents and fural, but is it possible to use it directly from the suction port without going through the suction sulfur part? , 14 tubes are asked (it is important that the tube is 14 in size, and the ratio of the volume of the residual space to the sampled metal body MK is usually 1).
Although it is desirable that the value be larger, a value smaller than 1 is also effective if the temperature is low. However, below 01, quantitative 1+1i becomes a low value. However, during hydrogen heating, hydrogen release from the sample may be promoted by heating at 150°C-f (it is known that heating up to 150 nm does not change the total value of fp 1 at all). ).

The above operation allows the bath OA to cut off the hydrogen released due to the rapid change in hydrogen solubility during solidification and the solidified sample. It is possible to properly soak the entire ridge without losing the hydrogen released over time.

Next, the present invention will be explained more specifically using examples.

Example 1 The collection container shown in Figure 4 (made of quartz, outer diameter 12 mm).

Inner diameter 10 rrun r length 150 wn, made of cold-rolled thin copper plate with internal dehydrogenation (1.3 van, diameter 6
ttan *Enclosed a special tube of length 7o) is used.
Continuous casting mold odor-C1, Dish 5S41
A considerable 5. [Two samples were taken from one grade of molten steel, 11M L. 1) Immediately 1r1 without cooling the 11 samples.
The stainless steel collection container 16 (shown in Figure 6) is connected to the sea urchin chromatograno thermal conductivity detection type gas analyzer D122 as shown in Figure 8, and each collection Fill the inside of the container 16 with Ar force for I+1. Then, with the valve 23'& closed, quartz jf as described above.
44'ile take'? ≠It was the 1st time I broke the vessel. Next, valve 23
．． 24 is opened and closed sequentially to transport the hydrogen in the collection container to a gas chroma (gas chroma) graph using an Ar carrier and heat it.
It was determined by L"fi degree detection. Next, each waste collection device was heated to 100°C with a heater 25, and
The amount of hydrogen emitted was determined in the same way as for each time b (all hydrogen values were quantified. The sum of these hydrogen constant values was defined as released hydrogen 1 and 1. After the aqueous system quantification was completed, the sample was taken out and 'f!l' bt L 1l
The weight between the chiller part and the conduit part is not related to illumination.
Sample after subtracting all? libt. Ha! The amount of ice water in molten steel (4X) was calculated from the amount of hydrogen released and the sample value. In addition, a part of the sample after water, I:', f41°1lll constant [
The residual hydrogen meter was determined to fit using a J+ cut-off inert gas melting-gas chromatography heat conductivity detection method. For comparison, the conventional method was also used to calculate -1? Two samples were collected using a quartz tube with suction, immediately cooled with water, cut, weighed, and melted in an inert gas bath. was set to constant K (
Conventional method (]) and approximately 6 self). The results are shown in Table 1.

Table 1 Hydrogen analysis values by the method of the present invention (jti position ppln)
As is clear from Table 1, in the conventional method, hydrogen released during solidification (corresponding to part of a in the quantitative results by the method of the present invention) is not quantified, and hydrogen in the sample (corresponding to part of a in the quantitative results by the method of the present invention) is not quantified. The value is low because some of the amount (equivalent) is dissipated during cutting and polishing, and the reproducibility is poor due to fluctuations in these factors. In addition, in the method shown in Fig. 2 and Fig. 3, hydrogen gas leaks from the seal part of the suction base and shows a low value, and in addition, the hydrogen tn shown in b is not recovered and the value becomes low (separately). ci addition). However, in the present invention, the rim is shaped like a tube so as not to create a suction base that would cause damage during transportation, and the collection container is completely housed within the collection container. The constant M′f of hydrogen released over time by installing a valve at:
In principle, the above problem can be solved by
[Stitch stitching 111 with good accuracy and reproducibility!] ! can be obtained.

EXAMPLE A collection container shown in FIG. 5 (the outside was made of stainless steel with a thickness of 0.5 mm and the suction port 10 had a plate r=0.1N).

Using the internal conduit 11 (made of porous aluminum), two samples were taken 11 times from the melting pot during the RH degaussing operation. Steel type &-1: Equivalent to SM 50. Place the container in the container shown in FIG. 7 and connect it to the analyzer 22 as shown in FIG. Container valve 2
3 was opened and hydrogen was fixed using the quadrupole type analysis rule.

Furthermore, close the valve 23, heat at 150°C, and heat at 319°C every 6 minutes.
1 passed away. The analysis results are shown in Table 2. For comparison, analysis results (conventional method (2) and abbreviated method) for samples collected using a vacuum quartz tube containing a stainless steel tube are also shown.

As is clear from Table 2, the conventional method (2) has poor reproducibility within the same sample. This is because water that entered the gap between the stainless steel tube and the sample when cutting the sample was not completely removed and was subjected to analysis H [11 & Ila].

According to the method of the present invention, there are no such female points, and accurate analytical values with good accuracy can be obtained.

In Examples 1 and 2, two samples were analyzed in parallel, but the ice water meter released from the sample was periodically placed, and the total amount of bt released until the release amount became almost 0 was hydrogen-1.
According to the principle of the present invention's method of determining the By opening and closing the valve 23 periodically, a large number of samples can be analyzed in parallel. Further, although the example in which the sample was heated has been described, it is also possible to obtain a constant line at room temperature.

Furthermore, in the embodiments, molten steel has been described, but it goes without saying that the present invention can also be applied to molten metals such as At.

Furthermore, regarding the sampling container, the collection container, and the gas analysis method, one embodiment of the method and apparatus Mk of the present invention was shown, but the method and apparatus Mk of the present invention were also shown. It goes without saying that correct values for the sheath layer can be easily obtained even in the embodiment of the example rig I.

As described above, according to the present invention, hydrogen in bath water is 1/
(To solve all the difficulties of the conventional method,
With positive 6'v, it is possible to obtain the L analysis result in sheath 11 with high efficiency.

[Brief explanation of drawings]

Figure 1 is a diagram of the relationship between the hydrogen solubility of pure iron and the 1:iA degree under 1 atm of hydrogen, Figure 2 is an example of a conventional sample and sample collection container, and Figure 3 is a graph of squares 1 and 2. An example of a gas analyzer in which hydrogen captured in a sample collection container is placed, FIGS. 4N and 5 are 65? , 2g6 and 7 are explanatory diagrams of a hydrogen gas collection container suitable for the actual bfIi of the present invention, and FIG. 8. FIG. 9 is an explanatory diagram of the FC hydrogen identification vertical apparatus a, which is also suitable for carrying out the present invention. 1; Fine plane tube, 2: Container for coagulation, 3: Tip, 4: Vacuum chamber, 5: Gas analyzer, 6: Closed container, 7: Sample collection 'a,
8: Suction base, 9: Collection container, 1o; Suction mouth, 11:4
Lee tube, 12: cold metal, 13: ventilation hole, 14: stationary phase,
15: Residual fully open, 16: Collection container, 17: Lid, 18:
Bellows, 19: Neno, 20: Blade, 21: Support, 22
:gas analysis B1.23, 24: valve, 25: heater, 26: y4e-no patent applicant $7 Figure 92

Claims (2)

[Claims] (1) Collect the bath molten metal in a part of the collection container that has been completely evacuated in advance, and place it in a gas collection container that is completely shut off from the outside air, and then combine the collection container with the collected and solidified metal. The amount of hydrogen in the molten metal is characterized by breaking the vessel wall of the formed space in the collection container and quantifying the hydrogen collected in the space as HFI and the hydrogen released from the solidified metal. Pointer method 0 (2) Rupture the space formed by the collection container that houses the sample taken from the bath molten metal together with the collection container while being isolated from the outside air, and the sample inserted into the container and the collection container. 1 mechanism, a valve that opens and closes the gas inlet and outlet of the collection container at a constant frequency, and a gas analyzer TL that measures the total amount of hydrogen gas in the collection container. Fixed fiber device 0