JP2551706B2 - High-speed transportation and preparation method of incandescent samples for iron and steel analysis - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for high-speed transport and preparation of a red-hot sample for steel analysis in the steel industry.

[0002]

2. Description of the Related Art In conducting a hot metal pretreatment process at a steelmaking plant, a secondary refining furnace such as a converter, an electric furnace, a ladle, a vacuum degassing furnace, etc. After cooling the collected incandescent sample for analysis at the factory, put it in the naked or in an air carrier to carry it to the analysis site, or
There is a method in which the red-hot sample is sent by air to the analysis site and cooled.
In addition, the conventional method for cooling a red-hot sample is to put the sample in cooling water with sample scissors for rapid cooling, or to gradually cool the sample while putting it in or out of the cooling water, or mechanical cooling water. A known method is a rapid cooling method in which the water is put in a bath or a method of gradually cooling while applying a shower, for example, JP-B-58-19476.

[0003]

In the case of the above manual cooling,
Since the temperature of the red-hot sample is different or the cooling time and the cooling method are not constant, there is large variation between the samples, and there is a decrease in the analysis accuracy due to the difference in the metal structure between the standard sample and the emission spectroscopic analysis. In addition, if the sample has a high carbon concentration, for example, a sample collected during converter blowing, or high carbon steel, cracking will occur if it is rapidly cooled in cooling water, and it will not be possible to discharge in the emission analysis and the analysis value will not be obtained. There are cases. On the other hand, in the case of rapid cooling in automatic cooling, a similar problem is inherent, and samples with a high carbon concentration in the sample, for example, samples taken during converter blowing are burned, and samples for chemical analysis are When cutting, it was hard and often caused cutting difficulties.
Further, in the method of intermittently spraying cooling water with a shower as described in Japanese Utility Model Publication No. 58-19476, it takes time to cool a red-hot sample to a temperature at which analysis can be performed, and in the operation in seconds at a steelmaking plant. However, there will be a wait for operation due to a delay in analysis.

According to the present invention, the incandescent sample for iron and steel analysis is cooled in a stable and immediately analyzable state in consideration of its expected carbon concentration to obtain a sample collected from any step of the steelmaking plant. It is intended to provide a high-speed transport preparation method for the purpose of further shortening the time until preparation of a sample for analysis in seconds.

[0005]

[Means for Solving the Problems] The present invention for achieving the above-mentioned object is as follows: (1) An analytical red hot sample taken from a steel manufacturing process is directly sent to a sample preparation area, and the expected carbon concentration of the red hot sample is Is higher than a specific carbon concentration, the cut sample portion of the red-hot sample is covered with a heat insulating member, and the red-hot sample is cooled in two stages with a cooling medium. (2) The analytical red heat sample taken from the steel manufacturing process is directly sent to the sample preparation area, and when the expected carbon concentration of the red heat sample is higher than a specific carbon concentration, the cut sample portion of the red heat sample and the portion thereof A high-speed transport and preparation method of a red-hot sample for iron and steel analysis, characterized in that the entire lower part is covered with a heat insulating member and cooled to the sample preparation temperature as it is. (3) The analytical red hot sample taken from the steel manufacturing process is directly sent to the sample preparation area, and when the expected carbon concentration of the red hot sample is higher than a specific carbon concentration, the cut sample portion of the red hot sample and the sample This is a high-speed transport and preparation method for a red hot sample for iron and steel analysis, characterized in that a lower part than a cut sample part is covered with a heat insulating member so as to have different heat insulating effects and then cooled to the sample preparation temperature as it is.

[0006]

[Function] If a steel analysis sample collected during high-carbon steel or high-carbon concentration converter blowing is rapidly cooled in a red-hot state, cracks may occur, or the metallographic structure may be martensite, pearlite, ferrite, or troostite. It becomes an organization in which the etc. are mixed. The present invention intends to adjust the cooling rate and the like of the red heat sample to the preparation temperature in consideration of the carbon concentration of the sample, and the expected carbon concentration of the red heat sample is a specific carbon concentration. Whether it is higher or lower can be specified based on the manufacturing specifications of the steel and by which process the sample is taken.

First of all, according to the present invention, an analytical red heat sample taken from a steel manufacturing process is directly sent to a sample preparation area, and when the expected carbon concentration of the red heat sample is higher than a specific carbon concentration, the red heat sample is cut. A sample portion to be processed (hereinafter referred to as a cut sample portion) is covered with a heat insulating member, and the red heat sample is cooled in two stages with a cooling medium. Specifically, if the sample is a red-hot sample having a carbon concentration such that it will have a different structure from the standard sample if cooled in a normal state, the cut sample part of the sample is covered with a heat insulating member, and the red-hot sample is kept at the same temperature. It is placed in a high-cooling medium such as hot water and gradually cooled to such a degree that cracks do not form at the bottom of the red-hot sample, and then the cooling medium is changed to cold water and cooled to the sample preparation temperature in water. Perform stage cooling. As a result, since the lower portion of the sample below the cut sample portion, that is, the sample bottom portion relatively close to the cut sample portion is gradually cooled, the occurrence of cracks is avoided,
In addition, the cut sample part of the sample is a heat insulating member,
Since it is cooled more slowly, a metal structure similar to that of the standard sample can be obtained.

Incidentally, in the case of the first stage cooling of the above-mentioned red-hot sample, that is, when the red-hot sample is first gradually cooled in warm water, the whole sample may be cooled by being immersed in warm water. In order to further shorten the time required for cooling to the preparation temperature, the head of the red-hot sample, that is, the portion which is not used for analysis, is projected from the warm water, and the time can be shortened by cooling with cooling water sprinkled there. By adopting this cooling method, even if a crack occurs in the sample head, the crack does not reach the cut sample part because there is a relatively large distance from the head to the cut sample part.

As another method of the present invention, an analytical red hot sample taken from a steel manufacturing process is directly sent to a sample preparation zone, and when the expected carbon concentration of the red hot sample is higher than a specific carbon concentration, the red hot sample is heated. The cut sample portion of the sample and the entire lower portion than the portion are covered with a heat insulating member and cooled as it is to the sample preparation temperature, so that the cut sample portion and the lower portion thereof are gradually cooled to have the same metallographic structure as the standard sample, No cracks will occur.

As yet another aspect of the present invention, an analytical red hot sample taken from a steel manufacturing process is directly sent to a sample preparation area, and a sample of an expected carbon concentration which causes cracks when the sent red hot sample is rapidly cooled In the case of 1, the cut sample portion of the red-hot sample and the lower portion of the cut sample portion of the sample are covered with a heat insulating member so as to have different heat insulating effects, and then cooled to the sample preparation temperature. Specifically, the same heat insulating member is used, and the thickness of the heat insulating member covering the cut sample portion is made thicker than the thickness of the heat insulating member in the lower portion, or the cut sample portion and the lower portion are different from each other. A covering method using a heat insulating member having a heat insulating effect can be selectively adopted. As a result, the cut sample part of the red-hot sample is gradually cooled to the same metallographic structure as the standard sample, and its lower part is rapidly cooled to the extent that no cracks form in the sample, so cool the entire red-hot sample in a short time. You can

The present invention will be specifically described below with reference to the drawings. Generally, a bomb type (inverted truncated cone type) sample 1 as shown in FIG. 2 is used as a sample for steel analysis. This sample 1 is collected from molten steel by using an octopus sampler, a probe and the like. The collected red-hot sample 1 is immediately conveyed as described later, and sample preparation such as cooling, cutting, and if necessary, polishing or cutting is performed in the sample preparation area. As shown in FIG. 3, the cutting in the sample preparation is performed by cutting one or two positions from the lower end of the bomb-shaped sample 1 at one or two positions to divide into cut samples A, C or A, B, C,
The cut sample A is discarded. If necessary, after polishing the surface of the cross section of the cut sample C, a plurality of elements such as carbon, silicon and manganese are analyzed by an emission spectroscopic analyzer. Further, a cut piece is cut out from a cut surface of the cut sample B, or a small piece is punched out to obtain a sample for chemical analysis or gas analysis.

For this reason, it is necessary to slowly cool the metal structure of the part to be cut and analyzed so as to be the same as that of the standard sample. In order to shorten the sample preparation time, it is better to quench the portion not used for analysis. However, when the carbon content of the sample to be sampled is high, quenching the above red-hot sample causes quench hardening and cracking.

The present invention pays attention to this part, and covers the cut sample part of the collected red-hot sample with a heat insulating member, and cools the red-hot sample in two stages of gradual cooling and rapid cooling to the sample preparation temperature. Covering the sample portion and the entire surface below the sample portion with a heat insulating member, or covering the cut sample portion of the red heat sample and the portion below the cut sample portion of the sample with a heat insulating member so as to have different heat insulating effects; and By cooling the sample preparation temperature as it is in such a state, only the vicinity of the cut sample portion is gradually cooled, the other portions are rapidly cooled to the extent that no cracks are formed, and the sample head is rapidly cooled.

FIG. 1 is a schematic explanatory view of an apparatus for carrying out high-speed transportation and preparation of a red hot sample for iron and steel analysis of the present invention. That is, the analytical red-hot sample 1 collected from the steel manufacturing process is sent by air from the sample sending device 12 as it is inside the air feeding pipe 11 and reaches the sample receiving device 10. In the heat insulating member attaching device 9 arranged on the downstream side of the sample receiving device 10, the cut sample portion of the red heat sample 1 is covered with, for example, an annular holder or a clamping jig which functions as the heat insulating member 7.

Since the red-hot sample 1 has sensible heat of 800 ° C. to 1100 ° C., the heat insulating member 7 is a substance that withstands this temperature, for example, metal materials such as steel, ceramics, glass, carbon materials, etc. Can be used alone or in combination. As the heat insulating member 7, a mode in which a processed product of the above material is stuck, wound, and applied so that only the heat insulating property of the material functions, or a mode in which a function of transferring a sample other than the heat insulating function is added is selectively used. can do.

In the example shown in FIG. 1, when the heat insulating member 7 made of, for example, an annular holder made of steel, which is processed from the above material, is made to stand by in the heat insulating member attaching device 9, the sample receiving device 10 is reached. The red hot sample 1 is dropped and fitted into the annular holder 7 from that position, and the red hot sample is held with the annular holder 7 positioned in the cut sample portion of the red hot sample 1 and transferred into the cooling tank 2. ing. Although not shown, the annular portion of the annular holder 7 may be divided into two parts to be a mechanism for sandwiching. Also,
As a specific example of another aspect of the heat insulating member 7, a fire-resistant shaped product such as a ribbon or a string may be wound, or a fire-resistant shaped product on a paste may be applied and covered.
The cut sample portion of the red-hot sample 1 is specifically in the range of 25 to 50% from the lower portion of the red-hot sample 1, and this portion is covered with the heat insulating member 7 of each of the above-described embodiments.

The red-hot sample 1 whose cut sample portion is covered with the heat insulating member 7 is put into the cooling tank 2 by the lift 8. In this case, if the sample is hardened by quenching or cracked when it is rapidly cooled from the expected carbon concentration of the red-hot sample 1, hot water is previously supplied from the hot-water supply nozzle 15 to the cooling tank 2, and the red-hot sample 1 is Slowly cool. At this time, the entire sample 1 may be immersed in warm water, but the cooling time can be shortened by projecting the head of the sample 1 from the warm water and sprinkling cold water from the sprinkling nozzle 14 on this part to cool it. After gradually cooling to the stage where there is no fear of cracks, cooling water is put into the cooling tank 2 from the cooling water supply nozzle 3, or the sample 1 is transferred to another container containing cooling water and cooled. The cooling pattern of this two-stage cooling can also be automatically set from the average received temperature of the red hot sample and the target carbon concentration.

As shown in FIG. 4, one specific example of the method of covering the cut sample portion of the red-hot sample 1 and the entire lower portion thereof with a heat insulating member and cooling the sample to the sample preparation temperature is as shown in FIG. 1. A mode in which the red-hot sample 1 is fitted into a cylindrical holder 17 having a recessed portion having a size and shape that is approximately half or less of that of No. 1, or a paste-like refractory amorphous product which is not shown but approximately half or less of the red-heat sample 1 Can be applied and covered.

Further, the cut sample portion of the red hot sample 1 and the lower portion of the cut sample portion of the sample are covered with a heat insulating member 7 so as to have different heat insulating effects, and are cooled to the sample preparation temperature as they are. The heat insulating member 7 is used, for example, the same heat insulating member is used, and the thickness of the heat insulating member 7 covering the cut sample portion is made thicker than the thickness of the heat insulating member 7 in the lower portion thereof, or the cut sample portion and the same. A method of covering the lower portion with the heat insulating members 7 having different heat insulating effects can be selectively adopted. As a specific embodiment, for example, an annular holder composed of a heat insulating member 7 holds the cut sample portion of the red heat sample 1, and a paste-like refractory amorphous material is applied to the lower portion thereof to improve the heat insulating effect of both. Various combinations can be adopted, such as making a difference or winding a ribbon-shaped fire-resistant fixed product, and making a difference in the heat insulating effect by changing the number of windings in the cut sample portion of the sample 1 and its lower portion.

The red heat sample 1 covered with the heat insulating member 7 as described above is immersed in the water in the cooling tank 2 by the lift 8 and cooled. The cooled sample 1 is taken out from the cooling water by the lift 8 and is blown with air from the air blowing device 13 to remove moisture, and then cut and used for analysis.

As described above, according to the present invention, a red-hot sample collected in a steelmaking factory is sent by air as it is, the cut sample portion is gradually cooled, paying attention to the carbon concentration in the sample, and the other portions are not cracked. This is a method of rapidly preparing a sample for analysis by rapidly cooling to a certain degree. Further, when the heat insulating member is an annular holder, a holding jig or a cylindrical holder, the transfer jig which is the heat insulating member constitutes a lift, so that the mechanism of the device can be simplified. As another method of the present invention, a method of manually performing a series of operations without an automatic device such as the heat insulating member attaching device 9, the lift 8, the solenoid valves 5 and 6 is also possible.

[0022]

【Example】

[Example 1] In the steelmaking process, a red-hot sample collected during blowing of a converter was conveyed as it was, and was connected to a lift having the same shape as the sample-cut sample part immediately after being received in the sample preparation area. The sample was fitted with an annular holder (thickness 5 mm, length 15 mm), immersed in warm water having a water temperature of 76 ° C. to a height of 5/6 of the sample, and cooled for 10 seconds. During this time, the sample head protruding from the hot water had 16
Water at ℃ was sprinkled. After cooling with hot water, continue to add water at 16 ° C for 20
Cooled for a second. After cooling, moisture was removed by air, cut and polished, and analyzed by an emission spectrometer.

[0023] Comparison was made with 10 samples each cooled without an annular holder (heat insulating member) and 10 samples cooled with each, and the analysis accuracy of carbon, which is the most important factor in making steel, is in-plane error. 49%, and 48% compared with the chemical analysis value, the one with the steel annular holder was good. In addition, when the microstructures were examined, the metal structure of the cut sample portion of the sample with the steel annular holder was mainly pearlite, while those without the steel annular holder were martensite, tall-stite, and pearlite. Etc. were mixed. Further, the metal structure of the portion other than the cut sample portion of the sample to which the steel annular holder was attached was similar to that without the steel annular holder, but no crack was found at the bottom of the sample.

[Embodiment 2] In the steelmaking process, the red-hot sample collected during the blowing of the converter is conveyed as it is, and the sample cutting sample part is connected to the lift of exactly the same shape immediately after receiving it in the sample preparation area. It is fitted and covered with a steel cylinder holder (thickness: 5 mm, depth: 30 mm) and immersed in water at a water temperature of 22 ° C.
Cooled for a second. After cooling, moisture was removed by air, cut and polished, and analyzed by an emission spectrometer.

When 10 pieces were made and compared with those without any heat insulating member, the analysis accuracy of carbon, which is the most important in making steel, is 48% in the in-plane error and 52% in comparison with the chemical analysis value. The one with a heat insulating member was good. Moreover, when the structure was examined, the metal structure of the cut sample portion of the sample with the steel annular holder was mainly pearlite, whereas those without the steel cylindrical holder were martensite, tallstite, Perlite was mixed. The metal structure of the other parts of the sample with the steel tubular holder was the same as that without the steel tubular holder.

[Embodiment 3] In the steel making process, the red-hot sample collected during the blowing of the converter is conveyed as it is, and the lift having the same shape as the sample cutting sample part and the lower part immediately after being received in the sample preparation area. Steel annular holder (5 mm thick, 15 mm long)
mm), and the lower part from the cut sample part is covered with a steel tube (thickness 0.5 mm) of the same shape as the sample connected to the lower end of the steel annular holder, and kept in water at a water temperature of 22 ° C. It was cooled for 30 seconds. After cooling, moisture was removed by air, cut and polished, and analyzed by an emission spectrometer.

When 10 pieces were made and compared with those without any heat insulating member, the most important carbon analysis accuracy in making steel is 50% in plane error and 52% in comparison with the chemical analysis value. The one with a heat insulating member was good. In addition, when the microstructures were examined, the metal structure of the cut sample portion of the sample with the steel annular holder was mainly pearlite, while those without the steel annular holder were martensite, tall-stite, and pearlite. Etc. were mixed. The metal structure except the cut sample part of the sample with the steel annular holder was the same as that without the steel annular holder, but no crack was observed at the bottom of the sample.

[0028]

INDUSTRIAL APPLICABILITY The present invention uses the heat insulating member to change the cooling conditions (insulation characteristics) of the cut sample portion, its lower portion and the head portion based on the expected carbon concentration of the red heat sample.
Since the cooling is performed by changing the cooling conditions such as two-stage cooling, the entire sample can be cooled quickly without cracking even if the carbon concentration in the sample is high. In addition, since the structure of the analysis site can be controlled in the same way as the standard sample, the analysis accuracy is improved, and since the parts other than those used for analysis are rapidly cooled, the red-hot sample is transported naked from the steelmaking plant, and component analysis can be performed in a short time. It is possible to operate the steelmaking plant smoothly.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an apparatus for high-speed transportation and preparation of a red hot sample for iron and steel analysis of the present invention.

FIG. 2 is a perspective view of an analysis sample.

FIG. 3 is an explanatory view of a state where an analysis sample is cut at the time of preparation.

FIG. 4 is a perspective view of a cylindrical holder according to the present invention.

[Explanation of symbols]

 1 bomb type sample 2 cooling tank 3 cooling water supply nozzle 4 cooling water discharge pipe 5, 6 solenoid valve 7 heat insulating member 8 lift 9 heat insulating member attaching device 10 sample receiving device 11 air feeding pipe 12 sample sending device 13 air blowing device 14 Sprinkling Nozzle 15 Hot Water Supply Nozzle 16 Electromagnetic Valve 17 Cylindrical Holder

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toru Mizutani 5-3 Tokai-cho, Tokai-shi, Aichi Nippon Steel Corporation Nagoya Steel Works (56) Reference JP-A-55-125218 (JP, A) Kaihei 5-172717 (JP, A) Jitsuko Sho 58-19476 (JP, Y2)

Claims (3)

(57) [Claims] 1. An analytical red heat sample taken from a steel manufacturing process is directly sent to a sample preparation zone, and when the expected carbon concentration of the red heat sample is higher than a specific carbon concentration, the cut sample portion of the red heat sample is thermally insulated. A high-speed transport and preparation method of a red-hot sample for iron and steel analysis, which is characterized in that the red-hot sample is covered with a conductive member and the red-hot sample is cooled in two stages with a cooling medium. 2. An analytical red-hot sample taken from a steel manufacturing process is directly sent to a sample preparation zone, and when the expected carbon concentration of the red-hot sample is higher than a specific carbon concentration, a cut sample portion of the red-hot sample and its A high-speed transport and preparation method for a red-hot sample for iron and steel analysis, characterized in that the entire lower part than the part is covered with a heat insulating member and cooled to the sample preparation temperature as it is. 3. An analytical red heat sample taken from a steel manufacturing process is directly sent to a sample preparation zone, and when the expected carbon concentration of the red heat sample is higher than a specific carbon concentration, a cut sample portion of the red heat sample and the A high-speed transport and preparation method of a red-hot sample for iron and steel analysis, characterized in that a lower part of a sample cut portion is covered with a heat insulating member so as to have different heat insulating effects, and is cooled to a sample preparation temperature as it is.