KR101038554B1 - Y type stud for forming water passage in the refractory of tundish and method for forming refractory of tundish using the same - Google Patents

Abstract

The present invention relates to a Y stud for forming a moisture passage of tundish refractory, which is attached to a tundish outer shell when the tundish refractories are installed and burned during preheating of the tundish to form a moisture passage, and a tundish refractory construction method using the same. will be.

To this end, the present invention is a flammable plastic, Y-type hollow tube produced in the form of a hollow pipe and a tundish refractory comprising a non-combustible Guro group material filled in the Y-shaped hollow tube Inserting and fixing the water channel forming quench stud and the wick stud into the water outlet hole formed in the outer shell of the tundish, fixing the tundish core in the tundish to which the chop stud is fixed, and the tundish A step of injecting an amorphous refractory into the space portion between the outer shell and the tundish core to cure, and preheating the cured tundish of the amorphous refractory to burn and remove the combustible Y type hollow tube of the Y stud to form a moisture induction furnace. Provides a tundish refractory construction method characterized in that consisting of a step.

Y stud, tundish, irregular refractory, guro, hollow tube, preheat, moisture removal

Description

Y TST FOR FORFORMING WATER PASSAGE IN THE REFRACTORY OF TUNDISH AND METHOD FOR FORMING REFRACTORY OF TUNDISH USING THE SAME}

1 is a schematic diagram showing a state in which the tundish is used in the performance equipment.

Figure 2 is a schematic diagram showing a preheated state of the tundish formed of the building refractory;

3 is a schematic diagram showing a preheated state of a tundish formed of an integral refractory;

4 is a perspective view and a front view showing a Y stud for forming a water passage of the tundish refractory according to the present invention;

5 is a schematic diagram showing a state in which the Y stud for forming the moisture passage of the tundish refractory according to the present invention is mounted on the tundish outer shell;

Figure 6 is a process chart showing the procedure of the tundish refractory construction method using the Y stud for forming the moisture passage of the tundish tundish refractory according to the present invention;

7 is a conceptual diagram illustrating a state in which a water passage is formed in the refractory by heating the tundish by the tundish refractory construction method using the Y stud for forming the water passage of the tundish refractory according to the present invention.

♣ Explanation of symbols for main part of drawing ♣

1: ladle 2: molten steel                 

3: tundish 4: mold

10: outer shell 12: standardized refractory

15: amorphous refractory 19: moisture outflow hole

20: start cap 21: residual moisture

22: effluent 25: tundish core

30: Y stud 31: main pipe

32: stem pipe 35: Guro matter

36: moisture induction furnace

The present invention relates to a Y stud for forming a moisture passage of tundish refractory and a tundish refractory construction method using the same, and more particularly, when the tundish refractory is constructed, it is mounted on a tundish outer shell and combusts when preheated by tundish The present invention relates to a Y stud for forming a moisture passage of a tundish refractory capable of forming a passage, and a tundish refractory construction method using the same.

As shown in FIG. 1, the tundish 3 serves as an intermediate container for controlling the flow of the molten steel 2 received in the ladle 1 and injecting it into the mold 4. The molten steel 2 injected into (4) is continuously cast to the cast piece 6 via the performance roll 5.

The tundish 3 is moved to the tundish repair shop after completion of the continuous casting operation to remove the residue and now in the tundish 3, and then introduced into the continuous casting process through the refractory repair process. Before the new or repaired tundish 3 is introduced into the playing process, the molten steel 2 can be stably received and supplied through a preheating process.

The preheating process is carried out in the order of drying → intermediate preheating → heating up, and this operation usually takes about 5 hours, and coke oven gas (COG), hot air, LPG, diesel, etc. may be used as a heat source.

The necessity of such preheating of the tundish 3 is as follows.

First, when supplying the molten steel (2) received in the ladle (1) to the tundish (3) to prevent a sharp drop in the molten steel temperature,

Second, it prevents the risk of tungsten refractory dropout and molten steel explosion due to the high temperature difference between molten steel (2) and tundish (3),

Third, the moisture remaining in the internal refractory of the tundish 3 is removed to prevent the moisture in the tundish 3 from penetrating into the molten steel 2.

In this tundish preheating process, a simple drop of the molten steel temperature and a molten steel explosion can be prevented by simple heating of the tundish 3, but a tundish preheating operation for removing moisture remaining in the internal refractory of the tundish 3 Is not simple and does not remove moisture even by high preheating, and as a result of many studies and technologies, it is common to carry out the above-described drying → medium preheating → heating.

Drying takes about 200 ~ 400 minutes at 20% (765,000 열 l / H) of the total heat source, 150 ~ 90 minutes at 40% (1,350,000㎉l / H) for intermediate preheating, and 60% (2,685,000㎉ / H) of heating. It is carried out so that it may be about 30 minutes or less, and there is an increase and decrease of a heating time according to the temperature of molten steel accommodated. In addition, when the drying time is long, the intermediate preheating time is short, and when the drying time is short, the intermediate preheating time is long. Such a preheating method is known as a commonly used technique.

There are two forms of the internal refractory material of the tundish 3 to which the present invention is applied. That is, it is divided into a structured refractory tundish (see FIG. 2) constructed with a standardized refractory (firebrick) 12 and an integral refractory tundish (see FIG. 3) that is flowed into an irregular refractory (mortal flowable refractory).

First, the shaped refractory tundish shown in FIG. 2 is made of a rigid outer shell 10, and is composed of a heat insulating refractory material 11, a shaped refractory material 12, and an amorphous ramming material 13. This structure protects the tundish 3 from the high temperature of the molten steel and maintains the temperature of the molten steel from the ambient temperature, but the coolant is sprinkled for cooling the tundish now and the sag during the tundish 3 repair work. And moisture contained in the shaping refractory 12 penetrates and remains between the outer shell 10 and the shaping refractory 12.

The cooling water thus penetrated is not easily dried due to the characteristics of the standardized refractory 12 even during drying → intermediate preheating → heating operation of the tundish (3), but the development of the construction of the refractory and constant tungsten outer shell (10) Perforated water outlet holes 19 at intervals are used to remove water from the refractory portion of the tundish 3 so as to be almost perfect by various methods and preheating techniques such as using it as a water moving passage.

However, there is a risk that molten steel may penetrate between the shaped refractory 12 and the shaped refractory 12 due to the structural characteristics of the shaped refractory tundish (FIG. 2), and a lot of time and advanced design techniques are required to build the shaped refractory 12. In addition, a high-performance building technician is required, and a cost increase factor occurs due to frequent refractories replacement. Recently, an integral refractory tundish (see FIG. 3) that has been constructed and introduced into an indefinite refractory (mortal type fluid refractory) has been utilized.

The inflow construction technique of the amorphous refractory (mortalized fluid refractory) is to put another smaller tundish shell (tundish core; 25) in the tundish shell (10), and the amorphous refractory (15) in between. It is a technology to install by injecting oil, and it has been spotlighted for quick and easy construction and long life.

However, the irregular refractory 15 constructed by the inflow construction method as described above has one whole tundish refractory, so that the water outlet hole 19 of the tundish outer shell 10 is blocked so that the outflow water flows out therefrom. (22) There is almost no, and because it is integral, water transfer path between refractory is blocked, so it is not enough water removal even when using heat source and time for water removal during preheating operation. Moisture penetrates into the molten steel (2) received in the) and remains. The moisture 21 that penetrates and remains causes the following problem.

First, the hydrogen content in the molten steel increases, causing a large amount of pinholes in the final cast, resulting in an increase in the cast cost due to an increase in the quality of the cast.

Second, the break out phenomenon occurs frequently during casting, and production is often stopped.                         

Third, the use of hot air and COG increases due to the internal preheating delay of tundish,

Fourth, the lifespan of tundish due to tundish deformation is shortened due to severe temperature variation due to tundish preheating and cooling.

Fifth, the clogging phenomenon of the molten steel discharge nozzle occurs during the initial performance of the start cap 20 due to excessive preheating.

In order to solve the above problems, the present invention is mounted on the water outlet hole formed in the outer shell when construction of tundish refractory by the inflow construction technique of amorphous refractory (mortal refractory refractory), drying and preheating after completion of construction The purpose is to provide a Y stud capable of completely burning in the process to form a moisture passage in the tundish refractory.

In addition, the present invention is mounted to the Y-stud in the moisture outlet hole formed in the outer shell of the tundish, and the hardened by the inflow of the indefinite refractory (mortal refractory refractory), then preheated to form a tungsten refractory construction Another purpose is to provide a method.

In order to achieve the above object, the present invention is a flammable plastic material, characterized in that the Y-type hollow tube made of a hollow pipe form, and the non-combustible Guro group material filled in the Y-shaped hollow tube Provided is a stud for forming a water passage of a tundish refractory.

In addition, the present invention is a tundish refractory, characterized in that the length of the Y-shaped hollow tube is formed to a length of 2/3 or less of the total refractory width, the angle of the central main pipe and the stem pipes on both sides is 150 ~ 175 degrees It is to provide a chopped stud for forming a water passage.

On the other hand, the present invention is the step of inserting and fixing the chopped studs in the water outlet hole formed in the outer shell of the tundish, the step of fixing the tundish core in the tundish fixed the chopped studs, the tundish outer shell Injecting and curing the amorphous refractory material into the space portion between the and tundish cores, and preheating the hardened refractory tundish to burn and remove the combustible Y type hollow tube of the Y stud to form a moisture induction furnace. Provides a tundish refractory construction method comprising a.

Here, the stud is fixed to the side of the iron bar is fixed so that the angle with the tundish bottom surface is 20 to 30 degrees, the Y stud fixed to the bottom of the outer shell is fixed so that the angle between the stem pipe 50 to 60 degrees do.

In addition, the present invention is a tungsten refractory construction method characterized in that the interval between the moisture induction furnace and the Guro group material in the step of forming a moisture induction furnace by burning the combustible Y-type hollow tube to remove the range. .

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration of the present invention.

Figure 4 is a perspective view and a front view showing a Y stud for forming a moisture passage of tundish refractory according to the present invention.

As shown in FIG. 4, the Y stud of the present invention is composed of a Y-type hollow tube 30 and an incombustible Guro group material 35 filled in an inner space thereof.

The Y-type hollow tube 30 is a flammable and burned plastic (polymer) material and is manufactured in the form of a hollow pipe, the combustion temperature of which is used in the vicinity of the preheating temperature range 500 ℃ desirable.

The Y-shaped hollow tube 30 is composed of the stem pipe 32 on both sides formed in communication with the main pipe 31 in the center, the angle formed by the main pipe 31 of the stem pipe 32 on both sides It is in the range of 150 to 175 degrees, which is for easily discharging moisture inside the refractory when mounted in the water outlet hole 19 formed in the outer shell 10 of the tundish, and also the stem pipe at an angle smaller than this range ( When the 32) is formed, the refractory construction becomes difficult due to inflow of irregular refractory materials, and when the stem pipe 32 is formed at an angle larger than this range, it becomes close to 180 degrees of me, and it is difficult to induce moisture existing in various places inside the refractory materials. For losing.

In addition, the end of the main pipe 31 of the Y-shaped hollow tube 30 is formed with a protrusion 33 which is almost similar to the size of the water outlet hole 19 formed in the outer shell 10 of the tundish, so that the water outlet hole ( 19) can be fixed firmly and stably.

The incombustible (or refractory) guro group material filled in the Y-shaped hollow tube 30 formed as described above is filled. Guro-based material is a common ceramic material used for bonding refractories or repairing refractory materials. Due to its physical properties, the Guro group material has soft and high ductility characteristics within about 1100 ° C. The Y-shaped moisture passage is formed in the irregular refractory to allow moisture to easily escape through the water outlet hole 19 of the outer shell 10 during the preheating operation.                     

However, when the molten steel 2 of 1400 ° C. or more is supplied from the ladle 1 to the tundish 3 and the temperature of the tundish refractory is increased, the Guro group material hardens and hardens at 1300 ° C. or higher due to its physical properties. 1.25 times expanded and closed the water induction path of the refractory to be constructed to prevent the leakage of molten steel in the tundish (3), as well as to make the inflow and refractories more robust to ensure a stable performance in the performance.

Hereinafter, the tundish refractory construction method using the Y stud of the present invention will be described.

Figure 5 is a schematic diagram showing a state in which the Y stud for forming the moisture passage of the tundish refractory according to the present invention is mounted on the outer shell of the tundish, Figure 6 is a Y stud for forming the moisture passage of the tundish refractory according to the present invention Figure 7 is a flow chart showing the sequence of the tundish refractory construction method used, Figure 7 is a tundish refractory construction method using a t-dish refractory construction method using the Y stud for forming a water passage of the tundish refractory according to the present invention to the moisture passage in the refractory It is a conceptual diagram which shows the state formed.

As shown in FIG. 6, the tundish refractory construction method is performed. First, the above-described Y stud of the present invention is inserted into the water outlet hole 19 at the side and bottom of the outer shell 10 of the tundish 3. Fix it.

At this time, the fixed form is, as shown in Figure 5, the tungsten insert and fixed to the water outlet hole 19 formed on the side of the tundish (3) outer shell 10 has an angle with the bottom surface of the tundish It is fixed to 20 to 30 degrees, the Y stud is fixed to the water outlet hole 19 formed in the bottom of the outer shell 10 to be fixed so that the angle between the stem pipe 32 is 50 to 60 degrees. This is all to facilitate the outflow of moisture remaining in the refractory material.

Then, the tundish core 25 is fixed in the tundish core 25, which is positioned in the inner space of the tundish iron shell 10, to form a fireproof space. After the amorphous refractory material 15 is introduced into the interspace formed by the tundish core 25, the amorphous refractory material 15 is hardened for a predetermined time. Start to warm up slowly.

When the preheating temperature of the tundish reaches 500 ° C., the hollow plastic portion of the Y stud filled with the Guro group material is burned and lost, and as shown in FIG. 7, the volume occupied by the plastic in the amorphous refractory 15 is Y. There is a water induction furnace 36 which is a space in a shape. The moisture induction furnace 36 is connected to the water outlet hole 19 of the tungsten shell 10.

Hereinafter, the embodiment of the present invention will be described in more detail.

[Example]

In the Y stud structure of the present invention, a plurality of stem pipes (32-outer diameter; 10 mm, inner diameter: 8 mm, thickness: 1 mm, length: 130 mm) are arranged in a Y-shape, and the other end thereof is the main pipe (31). 15 mm, inner diameter: 12.5 mm, thickness: 1.75 mm, length: 25 mm), the protrusion 33 formed at the tip of the main pipe 18 in a state in which a guro group material is filled therein. T is inserted into and fixed in the moisture outlet hole 19.

At this time, the Y stud is fixed at a predetermined interval (150 mm) in the water outlet hole 19 of the tundish bottom and the tundish bottom portion (up to 500 mm height from the tundish bottom). After the tundish core 25 is introduced and fixed, the amorphous refractory 15 is primarily filled up to a height of 500 mm from the bottom of the tundish.

It assembles the Y studs in the remaining water outlet holes 19 of the tundish shells 10 to 200 mm from the portion where the slag line is formed at the top of the tundish to the bottom and completely fills the irregular refractory 15.

In this case, it is important to consider that when the amount of slag flowing into the tundish intermittently increases, the slag line portion of the inflow construction refractory may be excessively eroded. It is important to do.

As described above, after the inflow-formed amorphous refractory has hardened to some extent, the tundish begins to preheat gradually, and when the tundish preheating temperature reaches 500 ° C., the plastic part of the Y stud filled with the Guro group material is lost and disappeared. In the amorphous refractory, the space is made in the shape of Y as much as the volume occupied by the plastic.

As shown in Table 1, when the Guro-type material and the clearance space are maintained at about 2 to 2.5 mm at an angle of about 25 degrees with the bottom part of the tundish hull, the water inside the tundish is external during the tundish drying operation. If the gap is smaller than that (1 ~ 1.5㎜), it is not easily discharged to the outside due to the surface tension between the Guro-group material and the refractory, so it takes more time to remove moisture, and if the gap is smaller (less than 1㎜) In the drying stage, only a very small amount of moisture is discharged to the outside and in the form of steam only during intermediate preheating, very much heat source and time are required.

Installation angle
(Deg) Water induction
(Mm) Refractory strength Moisture removal Remarks 35 1 or less Good Extremely poor No change in strength
Water removal 30 2 Good Bad No change in strength
Water removal 25 3 Good Good No change in strength
Good water removal 20 4 usually Good Strength reduction
Good moisture removal 15 5 Lowering Very good Risk of strength degradation collapse
Good moisture removal

On the contrary, when the gap is too large (3.5 ~ 4㎜), the tungsten material in tundish movement or inflowing refractories creates fluidity, and when the gap is more than 4.5mm, the strength of amorphous refractory is reduced. Because of the risk of collapse, the design of a suitable gap is very important.

In addition, the length of the Y stud should not exceed 2/3 of the total inflow refractory width, which is a part of the surface of the refractory eroded by the contact of the tungsten molten steel (2) and the refractory during continuous casting operation. This is to avoid direct contact with this Y stud. In general, the width of the tundish inflow refractories is designed to be about 10 times the maximum erosion, so in the case of billets, the width of the twirl inflow refractories is about 200 mm, so that a safety width of about 68 mm can be ensured even when a maximum erosion amount of 2 mm occurs. do.

As described above, the present invention forms a moisture flow path for discharging the internal moisture during construction of the irregular refractory at the time of tundish by using the Y studs, thereby effectively removing moisture during preheating the tundish, so that hydrogen such as pinholes in the slab can be efficiently removed. Defects are reduced, and the preheating time of the tundish is reduced, reducing the amount of heat source used, improving the quality of the cast, reducing the occurrence of breakout, and preventing the tundish deformation due to excessive preheating.

Claims (6)

Y-type hollow tube made of a flammable plastic material, hollow pipe shape; A chopped stud for forming a water passage of the tundish refractory, characterized in that consisting of a non-combustible guro group material filled in the Y-type hollow tube. The chopped stud for forming a water passage of a tundish refractory according to claim 1, wherein the length of the Y-shaped hollow tube is formed to be 2/3 or less of the total width of the refractory. The chopped stud for forming a water passage of the tundish refractory according to claim 1, wherein the Y-shaped hollow tube has an angle of 150 to 175 degrees between a central main pipe and a stem pipe on both sides. Inserting and fixing the hex stud of any one of claims 1 to 3 into a water outlet hole formed in the outer shell of the tundish; Fixing a tundish core to a tundish to which the chuck is fixed; Introducing an amorphous refractory into the space portion between the tundish outer shell and the tundish core to harden it; Preheating the refractory hardened tundish by burning the combustible Y-type hollow tube of the Y studs to form a moisture induction furnace comprising the step of forming a moisture induction furnace. The method according to claim 4, wherein in the step of fixing the chopped studs to the water outlet hole formed in the outer shell of the tundish fixed to the side of the outer sheath is fixed to the angle of the tundish bottom surface 20 to 30 degrees And, the Y stud is fixed to the outer shell bottom portion tundish refractory construction method characterized in that the angle between the stem pipe is fixed to 50 to 60 degrees. The method of claim 4, wherein the step of forming the water induction furnace by burning the combustible Y-type hollow tube to remove the tungsten refractory construction, characterized in that the interval between the water induction furnace and the Guro group material is in the range of 2 ~ 2.5mm Way.

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