KR100687620B1 - Probe for molten sample adhesion prevention of stainless steel - Google Patents

Abstract

The present invention effectively prevents the adhesion phenomenon between the sample and the sample chamber generated during the process of collecting the sample by immersing in the molten metal during the manufacture of the stainless steel for reducing the sample defect and for easier sample collection of stainless steel Relates to a probe.

The present invention is a sampling probe equipped with the hot and cold, the water, and the base of the ceramic material used to immerse to obtain the information of the molten metal in the molten ladle in the molten state in the molten state when manufacturing stainless steel To; On the inner wall surface of the loss, a cylindrical cold metal having an injection hole corresponding to the hot water spout and a flow passage space corresponding to the water spout may be internally fixed.

The present invention prevents adhesion between the chamber and the sample by incorporating cold metal into the loss during sampling of molten metal having a large specific heat and low thermal conductivity, and is easy to separate the sample from the chamber for component analysis. It is possible to collect the sample smoothly, improve the refining efficiency of steelmaking, increase the productivity, reduce the oxidation of valuable metals, and also reduce the cost of steelmaking.

Sampling room, probe, loss, basement, sample, stainless steel, cold

Description

PROOF FOR MOLTEN SAMPLE ADHESION PREVENTION OF STAINLESS STEEL}

1 is a cross-sectional view of main parts of a conventional general steel probe,

2 is a cross-sectional view of main parts showing an example of a probe according to the present invention;

3 is a cross-sectional view of main parts showing another example of a probe according to the present invention;

4 is a partial cross-sectional view of FIG.

5 is an exemplary perspective view of a cold chain according to the present invention.

6 is a sectional view of the main part according to an embodiment of the present invention;

♧ description of the symbols for the main parts of the drawing ♧

100 .... body 110 .... branch

200 .... temperature 210..compensation lead

310 .... 320 320..Lost

330 .... the bath 340 .... the

400 .... Cold 410 .... Inlet

420 .... Reinforcement part 430 .... Fixed groove

440 .... ceramic adhesive

The present invention relates to a probe used to obtain information of the molten metal, and more particularly, effectively prevents adhesion between the sample and the sampling chamber generated during the collection of the sample by being immersed in the molten metal during manufacture of the stainless steel. The present invention relates to a sample adhesion prevention probe of stainless steel that reduces sample defects and enables easier sampling.

In general, PROBE is a type of consumable measuring device that is immersed in molten metal to detect information such as temperature and composition of molten metal or to take a sample of molten metal.

As shown in FIG. 1, the probe has a body 1 formed by a plurality of branch pipes 2, and a thermocouple element for measuring a temperature of molten metal is disposed at the tip of the body 1. 3) is provided, and adjacent to the upper side is provided with a sampling section for collecting the sample, the sampling section is formed with a spout (4) formed by cutting a part of the branch pipe (2) so that molten metal can be introduced, and It consists of a chamber 7, which is a sampling chamber that is connected through an upper chamber 5 and a water bath 6 and stores a sample substantially.

In addition, the compensation lead 8 for transmitting the minute current signal measured from the temperature measuring part 3 has a structure in which it is embedded in the form between the branch pipes 2.

The measurement of the molten metal information of the stainless steel using the probe having such a structure is performed after the molten metal is tapped on the ladle.

That is, stainless steel is melted by arc heat generated through single phase direct current or three phase alternating current after charging primary scrap into an electric furnace, and then tapping into ladle after charging secondary scrap again to dissolve, heat and manufacture slag. It is manufactured through the process of tapping.

At this time, the temperature measurement and sampling work is accompanied to measure the information of the stainless steel, which is carried out in the ladle after the molten metal is tapped on the ladle.

However, since the molten stainless steel undergoes a refining process in a high temperature environment with a high carbon content and a high alloy state, it has a larger specific heat and a greater latent heat of solidification than ordinary steel, and the thermal conductivity is also low as 1/2 to 1/4.

As a result, the temperature drop of the molten sample introduced into the collecting chamber 4 after the high temperature molten metal flows into the spout 4 during the sampling operation and reaches the sampling chamber 7, which is the sampling chamber, is small, and thus, inside the chamber 7. While solidifying at the sample wall phenomena that would adhere to the inner wall surface of the basement (7), which is processed into cast iron or cast steel, caused the sample defects, and there was a problem of increasing the difficulty of sampling.

The present invention has been created in view of the above-mentioned problems in the prior art as described above, and the sample is collected in order to identify and predict the composition of high temperature, high carbon, high alloy steel in the electric furnace process for manufacturing stainless steel In this case, it is possible to reduce the sample defect and to easily collect the sample for component analysis by preventing the adhesion between the basement and the sample caused by the large specific heat of the injected molten metal and the low thermal conductivity. The main object is to provide a sample adhesion prevention probe of stainless steel.

In order to achieve the above technical problem, in order to achieve the above technical problem, in the manufacture of stainless steel, hot and cold, hot and cold, the ceramic material used to immerse to obtain the information of the molten metal in the ladle tapping in the molten state through an electric furnace process In a sampling probe having a diagram and a chamber; The technical feature is to provide a probe for preventing sample adhesion of stainless steel by internally fixing a cylindrical cold metal having an injection hole corresponding to the spout and a distribution space corresponding to the spout.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

2 is a cross-sectional view of the main part showing an example of a probe according to the present invention, FIG. 3 is a cross-sectional view of the main part showing another example of the probe according to the present invention, FIG. 4 is an enlarged view of a portion A of FIG. 3, and FIG. 5 is the present invention. Is an exemplary perspective view of a cold chain according to the invention.

As shown in FIG. 2, the probe according to the present invention includes a body 100 consisting of a branch pipe 110, a sample consisting of a temperature measuring part 200 provided at a tip of the body 100, and an upper and lower chambers 320 and 340. Comprising a portion, the compensation wire 210 for connecting the temperature measuring unit 200 and the control unit (not shown) is disposed in a state buried in the branch pipe 110 via both sides of the sample collector.

At this time, the loss 320 is usually made of a ceramic material, the one side is provided with a tanggu 310 and the lower surface of the tangdo 330 is formed to serve as a pressure to the room 340.

In addition, the basement 340 is positioned directly below the water supply 330 to serve as a case of the sample, and take a main function of collecting and storing the sample.

Furthermore, the temperature measuring part 200 has a structure that may be mounted or detached as necessary.

Such a configuration would be in the same or similar category as a conventional probe.

In addition, another embodiment shown in FIG. 3 is for explaining the shape difference of the water inlet 330, thereby causing a change in the shape of the loss 320, the material properties of the measurement object, that is, the molten metal There may be a variety of variations depending on.

For example, compared to the ballway 330 shown in FIG. 3, the ballway 330 ′ shown in FIG. 3 has a shape in which a top surface contacting the loss chamber 320 protrudes a predetermined height further toward the loss chamber 320. This is to facilitate the separation of the loss and the room by inhibiting the generation of residual waste in the room at the time of separation for sample analysis.

The present invention is characterized by embedding the cold gold 400 on the inner circumferential surface of the loss 320 constituting the sample collection.

A chiller or chilling block refers to a piece of metal, ie a cooling metal, that promotes cooling of the part by bringing it to places where the casting thickness is not easy to induce shrinkage, particularly where the tissue is desired to be fine.

Therefore, the cold gold 400 lowers the temperature of the molten metal introduced into the loss chamber 320 through the hot water hole 310.

As shown in FIGS. 4 and 5, the cold gold 400 has an inlet 410 formed on one surface thereof to heat the cold gold 400 locally or to smoothly flow the introduced melt. It is preferable that it is formed in a pipe shape, ie, cylindrical.

In addition, the front inner portion of the inlet 410 in which the injected molten metal causes the greatest friction with the cold metal 400 forms a reinforcement portion 420 whose thickness is thicker than that of other portions, thereby increasing the temperature drop of the sample melt even more. Can be. At this time, the reinforcing portion 420 is preferably formed to be 1.5 to 2 times thicker than the peripheral thickness of the injection hole 410.

In addition, when the cold metal 400 is inserted into the loss chamber 320, the cylindrical cold shell 400 may be rotated in the inside of the loss chamber 320 during the movement or use, and thus, fixing thereof is required. Particularly preferably, at least one fixing groove 430 is formed on a portion of the upper surface or a portion of the lower surface of the 400 and the high temperature ceramic adhesive 440 is fixed to the fixing groove 430.

In addition, since the molten metal of the stainless steel electric furnace is high carbon, high alloyed state, the carbon content is about 2.0 to 2.5%, and thus the cold metal 400 may not be made of ordinary copper or cast iron, and a material having excellent specific heat and thermal conductivity may be used. Required.

To this end, the cold gold 400 is particularly preferably used 0.1% ~ 0.2% C low carbon steel, because it is excellent in high melting point and high temperature characteristics, and easy to process and use.

In addition, the thickness of the cold metal 400 is suitable 2 ~ 6mm, more preferably 3 ± 0.5mm.

The reason for this is that if the thickness of the cold metal 400 is too thin, there is a risk of melting by hot molten metal injected thereinto damage the integrity of the sample, and if too thick, the cold metal 400 is injected into the base 340 through the water bath 330. This is because the negative effect of increasing the temperature drop of the molten metal, which causes solidification defects and increases the volume of loss, is dominant.

Further, the sample collection room may be added with a deoxidizer to ensure the integrity of the sample.

In this case, in order to maximize the cooling of the molten metal to be collected, it may be possible to design the upper chamber 320 itself by a relatively large cooling metal, but the upper and lower chambers 320 and 340 of the collected sample are adhered to each other to obtain a desired sample. The disadvantage of requiring another desorption device is mass produced, and the external shape of the sampler or the probe generally uses a multi branch pipe (110). Since the compensation wire 210 is transmitted to the current having a minute level of the embedded buried heat of the loss 320 having a higher heat than the basement 340 to the compensation wire 210 inside the branch pipe 110 as it is If leaked, it may cause a problem of temperature measurement deviation.

In order to prevent this, there may be a method of increasing the thickness of the branch pipe 110 or thickening of the loss 320, but in this case, it may cause a cost increase of the probe, a disposable consumable, and is required for the probe immersion apparatus due to the weight increase. In addition to the above load, not only is not efficient, but also the melt may solidify in the loss 320, so that obtaining a desired sample is difficult.

Therefore, since the ceramic material of the loss 320 has a favorable design in many aspects, such as sample separation, insulation ability, and light weight after sampling, in order to enable a smooth sampling while maintaining its characteristics, the loss of the cold gold 400 as in the present invention is lost (320). ) It is very advantageous to collect the sample and to separate the sample for component analysis after collection.

The present invention composed of such a configuration has the following operating relationship.

The probe of the present invention is immersed in a molten stainless steel molten metal after melting in an electric furnace.

Accordingly, it is possible to measure not only the sample for the component analysis of the stainless steel molten metal but also the measurement of the temperature.

In this case, the temperature measuring part 200 provided at the tip of the probe may or may not be attached as necessary, and thus only the sampling process will be described.

That is, when the body 100 of the probe is immersed in the stainless steel molten metal tapping on the ladle, a portion of the molten metal is introduced into the loss 320 through the molten iron 310.

The introduced sample melt is brought into contact with the inner circumferential surface of the cold metal 400 embedded in the chamber 320, and in this process, the temperature of the sample melt is induced as heat exchange occurs.

Subsequently, the temperature-reduced sample molten metal is slowly introduced into the basement 340 while being melted through the tap water 330, and when the base molten metal is filled in the basement 340, the temperature of the sample molten metal is significantly lower than that of the initial inlet 310. Have a distribution.

Therefore, when the sample molten metal solidifies in the chamber 340, which is the sampling chamber, the melt superheat degree is lower than before, and thus the adhesion phenomenon with the inner wall of the chamber 340 is drastically reduced, thereby making it easier to separate the sample. Secured.

Hereinafter, the effect on the temperature drop of the cold gold 400 will be described as an example.

The cold metal 400 is made of high-temperature piping steel or alloy steel for piping, and the thermal conductivity (k) is about 46 W / m ° C, and the inner space is Φ21 mm * 44 mm-> about 15 cm 3 and thickness (t). Designed in mm.

The molten metal flowing into the loss chamber 320 through the pouring hole 310 at 1600 ° C is filled with a large amount in the instantaneous loss 320 due to the very high speed and large vortex by the iron positive pressure, and through the water supply 310 It is moved to 340.

This is done in a time of approximately 0.1 to 0.2 seconds, thereby forming a vant between the chamber 340 and the loss 320, in order to facilitate the discharge of the air trapped in the chamber 340, the sample without the band In the case of the seal, gas is trapped inside the sample melt, causing bubble defects.

Ideally, it is assumed that the sample 320 is completely filled in the chamber 320 and moved to the chamber 340, and the heat (q ') transferred to the cold metal when the molten stainless steel at a specific heat of about 0.5 J / g ° C is injected is heat conduction. It can be explained by the following equation regarding the distance (delta x) between the figure (k), the temperature difference T1-T2, the contact area A and the temperature difference.

At this time, the contact area (A) is about 25 cm 2, the temperature difference (T1-T2) between the cold gold 400 and the chamber 320 is about 1570 ℃, the difference between the molten contact surface temperature and room temperature, and Δx is 3mm thick, so it is substituted. By solving Equation 1, the column q 'has about 60000W.

At this time, the temperature drop of the molten metal may be influenced by tropical flow and heat conduction, but the effect by the former is less than that by the latter, so looking only at the temperature drop due to heat conduction, the dropped temperature (T3) is the initial temperature ( T1), heat (q '), specific heat (c), the melt mass (m) can be described by the following equation.

At this time, if about 8 g / cm 3 of molten metal is filled in 15 cm 3 of internal space, the melt mass (m) is 120 g, and the specific heat (c) is 0.5 J / g ° C. The temperature drop of about 100 ° C can be confirmed, and the temperature of the molten metal injected into the basement 340 through the water bath 330 at the initial temperature (T1) 1600 ° C is expected to be about 1400-1500 ° C. .

Therefore, in the case of the conventional sample chamber without the cold metal 400, the thermal conductivity of the ceramic is about 0.037 W / m ° C., so that the temperature drop due to the thermal conductivity in the upper chamber 320 is very small at about 0.1 ° C. per 0.1 second.

However, the molten stainless steel of the electric furnace has a superheat of about 200 ℃ of the molten metal due to the cold gold 400 can be lowered to the superheat of the molten metal injected into the room 340 to 100 ℃ or less in the conventional probe Adhesion defects in the inner wall surface of the molten base 340 that have been generated can be controlled.

As described in detail above, according to the present invention, by incorporating cold gold into the loss in the process of sampling the molten metal having a large specific heat and low thermal conductivity, it is possible to prevent the adhesion between the chamber and the sample in advance.

In addition, it is easy to remove the sample from the base for component analysis, so that it is possible to collect the sample smoothly, improve the refining efficiency of steelmaking, increase productivity, and shorten the working time, thereby reducing the occurrence of oxidation of valuable metals. Cost savings from steelmaking can also be achieved.

Claims (4)

delete Claims [1] A sampling probe having a spout, a loss, a spout, and a base of a ceramic material, which is immersed and used to obtain information of molten metal in a molten state in a molten state in a molten state when manufacturing stainless steel; On the inner wall surface of the loss, The internally fixed cylindrical cold gold having an inlet and a corresponding flow space corresponding to the tap opening, wherein the cold gold is a low carbon steel material of 0.25% C or less, and has a thickness of 2 to 6 mm. Prevention probe. The method according to claim 2, The cold gold is a groove for forming a fixed groove in the upper or lower portion of the bottom surface, the sample groove preventing probe of stainless steel, characterized in that the fixing groove is inserted into the ceramic adhesive is fixed to the inner wall surface of the loss. The method according to claim 2, The cold gold is a sample adhesion prevention probe of stainless steel that the reinforcing portion relatively thicker than the thickness of the inlet side is formed on the opposite side of the inlet.

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