JPH07232248A - Filling material and fitting method for nozzle for continuous casting of metal - Google Patents

Abstract

PURPOSE:To improve the air-tightness of a fitting part and to enable maintaining of the stable function even in the case of using a nozzle for a long time in a hot state by containing an oxide having the temp. becoming the specified viscosity in the temp. range from room temp. to the temp. of molten metal. CONSTITUTION:In the case of using the divided type pouring nozzle in a continuous casting process of the metal, a recessed part 2 at a part of the fitting surface of the fitted immersion nozzle or long nozzle 1B and a projecting part 3 on the fitting surface at the upper part of an upper nozzle 1A are arranged. At the time of fitting both nozzles 1A, 1B, filling material 8 is filled in a groove of the recessed part 2 arranged on the fitting surface at the immersion nozzle or long nozzle 1B side and after preheating, both nozzles are fitted. At this time, the oxide having the temp. becoming viscosity of 10<4>-10<5> poise in the temp. range from room temp. to the temp. of molten metal is contained in the filling material 8. Therefore, the gap of the fitting part is sealed with the filling material 8, and in this result, the air-tightness of the fitting position is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filling material and a fitting method in a nozzle for continuous casting of metal.

[0002]

2. Description of the Related Art Conventionally, an upper nozzle 1C and a dipping nozzle or a long nozzle 1 as shown in FIG.
The fitting portion with D and the fitting portion between the lower plate 2C of the sliding nozzle device 5 and the dipping nozzle or the long nozzle 2D equipped on the bottom portion 7 of the tundish as shown in FIG. 4 maintain airtightness. For this reason, when the filler material is sandwiched between the fitting portions and compressed to be fitted, a filling material composed of an amorphous refractory material or a kneaded product of an amorphous refractory material and an organic resin has been used. Further, as in the invention of Japanese Patent Application No. 5-14260, the fitting portion between the upper nozzle 1A and the immersion nozzle 1B of the tundish 1 as shown in FIG. 1 and the bottom portion of the tundish as shown in FIG. There is a joining mechanism in which unevenness is provided in the fitting portion between the lower plate 2A and the immersion nozzle 2B of the equipped sliding nozzle device 5, and a method of filling and joining the liquid sealing material to the uneven portion is shown.

[0003]

However, in the case of the conventional fitting portion filling material as described above, a hardening type or compression dense type material which has sinterability in hot is adopted. As a result of changing the airtightness of the fitting part due to the occurrence of hot shrinkage and hardening cracks, as a result, when the molten metal passes through the nozzle, the outside air surrounding the fitting part is sucked in and the molten metal It became a mixed flow in which gas bubbles were turbid inside, and the flow resistance in the nozzle increased and the pouring amount control became unstable. Alternatively, the molten metal is contaminated, which causes a problem related to the airtightness of the nozzle fitting portion, or causes a quality problem. Further, regarding the liquid sealing material in the invention of Japanese Patent Application No. 5-114260, it is sometimes preferable to select a material which has a sealing property at room temperature and is completely liquefied in a high temperature region to exhibit high viscosity. However, the specific material and viscosity were not described, and there was a problem in selecting the material.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems, and the summary thereof is as follows.

First, (1) during continuous casting of a slab from molten metal, the fit between the upper nozzle at the bottom of the ladle or the lower plate of the sliding nozzle device and the long nozzle connected therebelow. A filling material that is used by filling the joint part or the fitting part between the upper nozzle of the tundish bottom or the lower plate of the sliding nozzle device and the dipping nozzle connected thereunder, which is melted from room temperature. Within the temperature range up to the temperature of the metal, its viscosity is 10 ⁴ pois
e and an oxide having a temperature of 10 ⁵ poise, in particular, (2) the oxide is boron oxide or an oxide containing boron oxide, and (3) an oxide containing boron oxide. Is a composition containing 90% by weight or more of boron oxide, and 10% by weight or less of powder of one or more kinds of alumina, silica and zirconia having a particle diameter of 1 μm or less in the balance, a nozzle for continuous casting of metal. It is a filling material for the fitting part in.

Secondly, (4) during continuous casting of a slab from molten metal, the fit between the upper nozzle at the bottom of the ladle or the lower plate of the sliding nozzle and the long nozzle connected therebelow. At the joint, at the fitting between the upper nozzle of the tundish bottom or the lower plate of the sliding nozzle device and the immersion nozzle connected below it,
The viscosity is 10 within the temperature range from room temperature to the temperature of the molten metal.
Cooling the outer periphery of the nozzle of the fitting part after filling and fitting a filling material containing an oxide having a temperature of ⁴ poise and 10 ⁵ poise, in particular, (5) the oxide is boron oxide or An oxide containing boron oxide, and (6) the oxide containing boron oxide is 90% by weight or more of boron oxide, and the balance is alumina or silica having a particle diameter of 1 μm or less,
A fitting method for a nozzle for continuous casting of metal, which is a composition containing 10% by weight or less of one or more powders of zirconia.

[0007]

The function of the present invention will be described in detail below.

The present inventor has conducted various studies to solve the problems in the prior art, and as a result, as shown in FIG. 3, a nozzle for continuous casting of metal was assembled from a plurality of parts. When using the split type pouring nozzle,
When passing molten metal through the nozzle, it is easy to suck the outside air from the gap of the fitting part, and the molten metal injection flow becomes a mixed layer flow in which gas bubbles are turbid, increasing not only the flow resistance in the nozzle but also the upper part. It was elucidated that a stagnant gas chamber was created in the tank and a secondary meniscus was formed in the pouring nozzle, making the flow of molten metal more unstable.

Therefore, as a result of disassembling and investigating the conventional split type pouring nozzle after several charges have been used, the filling material 6 used for the fitting portion has several cracks with a width and uneven thickness. Or I found some misalignment.

On the basis of the above results, when the split type pouring nozzle is used in the continuous metal casting process, as shown in FIG. 1, a part of the fitting surface of the immersion nozzle or the long nozzle 1B to be fitted is used. The concave portion 2 and the upper nozzle 1A facing the concave portion 2
The convex portion 3 is provided on the fitting surface of the above, and when the both nozzles are fitted, the groove of the concave portion 2 provided on the fitting surface of the immersion nozzle or the long nozzle 1B is filled with the filling material 8 according to the present invention, Mate after preheating. As a result, it has been found that the filling material is sealed in the gap of the fitting portion, and as a result, the airtightness of the fitting portion is increased, and the stable function can be maintained even when used for a long time in hot condition.

The same applies to the case where the lower plate 2A of the sliding nozzle device 5 and the immersion nozzle or the long nozzle 2B as shown in FIG. 2 are combined.

Further, the fluidity was investigated by changing the temperature of the filling material. As a result, as shown in FIG. 5, even when the fitting surface of the immersion nozzle or the long nozzle 3D is flat and the fitting surface of the upper upper nozzle 3C facing each other is also flat, when both nozzles are fitted together, If the temperature of the filling material 8 provided on the fitting surface of the immersion nozzle or the long nozzle 3D is appropriately selected and the viscosity is adjusted, the filling material 8 will not flow out and be lost. Therefore, by filling the necessary amount, filling it, and fitting it, the filling material is sealed in the gap of this fitting part,
As a result, it was also found that the airtightness of the fitting part becomes high and the stable function can be maintained even when used for a long time while hot.

The same applies to the case where the lower plate 4C of the sliding nozzle device 5 and the immersion nozzle or the long nozzle 4D as shown in FIG. 6 are combined.

As the filling material 8 used for the fitting portion,
When the nozzle is preheated and then fitted, a fitting method that facilitates the work and obtains sufficient airtightness and that can secure the airtightness during casting is desired, and earnest research has been conducted.

As a result, the workability when fitting the nozzle after preheating is that the viscosity of the filling material 8 is 10 ⁴ poi.
If it is se, the fluidity at the time of fitting is good, the fitting is easy, it is easy to handle, and at the same time, in terms of function, the filling material easily flows in the gap of the fitting part and It has been found that uniform filling can be achieved and the airtightness is improved, and that the airtightness can be secured for a long time. It was also found that the viscosity is 10 ⁵ poise and the functional improvement such that the airtightness can be secured for a longer time can be achieved.

Therefore, the filling material for the fitting portion of the continuous casting nozzle is a liquid oxide having a viscosity of 10 ⁴ poise and 10 ⁵ poise in the temperature range from room temperature to the temperature of the molten metal. This is a technical point for ensuring workability at the time of joining and airtightness during casting.

As a result of further studies, boron oxide is suitable as a specific composition having such properties in the temperature range from room temperature to the temperature of the molten metal, and boron oxide One of alumina, silica, and zirconia having 90% by weight or more and the balance having a particle size of 1 μm or less.
It has been found that a composition containing less than 10% by weight of one or more powders is suitable.

That is, boron oxide is 10 ⁶ poi at 500 ° C.
Although it has a high viscosity of se, it becomes liquid, and the fluidity at the time of fitting at 800 ° C. is improved, resulting in a viscosity of 10 ⁴ poise that allows easy fitting. Also, the middle 60
At 0 ° C., the viscosity was 10 ⁵ poise, which can ensure the airtightness for a long time.

On the other hand, when it was investigated whether or not such properties of boron oxide could be stably obtained, it was found that refractory raw materials such as alumina, silica, zirconia, etc., which may be mixed in from a nozzle at the time of fitting, with respect to boron oxide. It was also found that even if 1% by weight was mixed, there was almost no change and the same properties were maintained. Therefore, when these fillers are filled with the filling material composed of only boron oxide, there is no problem in practical use.

Refractory powders of alumina, silica, zirconia and the like having a particle size of 1 μm or less have a high viscosity of 10 ⁶ poise but a liquid temperature of 500 to 700 ° C. as the content increases. The temperature rises in the range, and the fluidity at the time of mating improves in the range of 800 to 1000 ° C, which facilitates mating 10 ⁴ po
It becomes the viscosity of ise. In addition, from 600 ℃ in the middle to 800
At 0 ° C, the viscosity was 10 ⁵ poise, which can ensure airtightness for a long time.

As a result, when boron oxide is used as a filling material for the fitting portion, the fitting portion of the nozzle is heated to 500 ° C. or higher, preferably 800 ° C., during preheating, so that the mating portion can be fitted. It is possible to uniformly fill the space between the fitting surfaces. Further, the airtightness of the fitting portion was sufficiently maintained even during casting.

When a composition containing a fire powder such as alumina, silica or zirconia is used as a filling material for the fitting portion, the fitting portion of the nozzle is preheated to 500 ° C. or more depending on the amount of the refractory powder. Alternatively, by heating to a temperature of 700 ° C. or higher, preferably by appropriately selecting the heating temperature of the fitting portion within the temperature range of 800 ° C. to 1000 ° C., the filling material is uniformly filled between the fitting faces when fitting. Therefore, the fitting portion is sufficiently airtight during casting.

On the other hand, a case was investigated in which the nozzle was fitted after being preheated and then the fitting portion was cooled. As a result, hermeticity was maintained sufficiently. In this method, hermeticity is ensured by the filling material, and thus
The purpose of flowing the gas is to cool the fitted parts. Therefore, as shown in FIG. 7, in order to cool the fitting portion, an annular pipe surrounding the fitting portion is provided, and a cooling gas flow is sprayed from the nozzle provided inside the pipe to the fitting portion to cool it. . Argon, nitrogen, air or the like can be adopted as the gas species at that time.

Further, even when the dipping nozzle or the long nozzle is replaced midway for some reason while using the split type pouring nozzle based on the conventional method,
There is no problem even if the split type injection nozzle filled with the fitting portion filling material according to the present invention is used.

A detailed description will be given below based on embodiments.

[0026]

【Example】

(Example 1) Regarding the filling material of the fitting portion of the immersion nozzle, in order to compare the airtightness, the case of using the conventional filling material 6 and the case of using the filling material 8 according to the present invention were examined. First, a split type pouring nozzle, that is, a combination of the upper nozzle 1A and the lower nozzle 1B in FIG. 1, or 1C and 1 in FIG.
A fitting model was made by the combination of D and the combination of 3C and 3D in FIG. Next, the filling material was placed in the fitting portion, and the upper and lower nozzles were fitted in a furnace 10 heated by a burner 9 at a high temperature as shown in FIG. After that, the airtightness evaluation test of the nozzle is shown in FIG.
The apparatus was used under the following experimental conditions. The fitting temperature was set to a temperature at which the filling material did not flow out when the fitting surface was flat. In the evaluation of airtightness, the ventilation amount and time at the time of stability were used as evaluation values, and the results of Table 1 were obtained to confirm the effectiveness of the present invention. In FIG. 8, 11 is a flow meter and 12 is a vacuum gauge. The airtightness evaluation temperature was the average temperature of the nozzle fitting portion when molten steel was poured into the immersion nozzle and filled, and the outer peripheral portion was naturally cooled. That is, the state in which the filling material is present in the fitting portion and the inside of the furnace 10 is kept at 1200 ° C. by the burner 9 corresponds to spontaneous cooling. Experimental condition (1) Shape 150 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature 600 ° C. (3) Filling material Material according to the present invention: Boron oxide Comparative material: Amorphous refractory + organic resin (4) Pressure 100 Kg / cm ² (5) Differential pressure between nozzle and atmosphere 200 torr (6) Airtightness evaluation temperature 1200 ° C

[0027]

[Table 1]

If the filling material according to the invention is used,
Compared with the case of using an amorphous refractory and a resin as the filling material as in the comparative example, the air permeability is small and the airtightness is good for a long time. Therefore, it can be seen that the filling material of the present invention is superior.

(Embodiment 2) Regarding the filling material of the fitting portion of the immersion nozzle, in order to compare the airtightness, the conventional filling material 6 was used.
And the case of using the filling material 8 according to the present invention. First, a fitting model using a combination of the split type pouring nozzle, that is, the upper nozzle 1A and the lower nozzle 1B in FIG. 1 was produced. Next, the filling material is placed on the fitting portion, and the filling material shown in FIG.
In the furnace 10 heated by the burner 9 as described above, the lower nozzle was fitted under a high temperature with a load being applied to the upper portion of the nozzle. After that, an airtightness evaluation test of the nozzle was performed under the following experimental conditions using the apparatus shown in FIG. In the evaluation of airtightness, the ventilation amount and time at the time of stability were used as evaluation values, and the results of Table 2 were obtained to confirm the effectiveness of the present invention. Experimental condition (1) Shape 150 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature Varies depending on the amount of refractory powder (3) Filling material Material according to the present invention: Boron oxide + refractory powder Comparative material; Irregular refractory + organic resin (4) Pressure 100 Kg / cm ² (5 ) Pressure difference between nozzle and atmosphere 200 torr (6) Airtightness evaluation temperature 1200 ° C

[0030]

[Table 2A]

[0031]

[Table 2B]

If the filling material according to the invention is used,
Compared with the case where the filling material of the comparative example was used at an air flow rate of 0.2 liter / min, the air flow rate was as small as 1/10,
Good airtightness. Therefore, it can be seen that the filling material of the present invention is superior.

(Embodiment 3) In order to compare the airtightness after fitting of the immersion nozzle, the case of using the existing filling material 6 and the case of using the filling material according to the present invention were examined. First, the split pouring nozzle, that is, the upper nozzle 3 in FIG.
A fitting model was prepared by combining C and the lower nozzle 3D. Next, the filling material was placed in the fitting portion, and a load was applied to the upper portion of the nozzle at a high temperature in the furnace 10 heated by the burner 9 as shown in FIG. 8 to fit the upper and lower nozzles. after that,
The airtightness evaluation test of the nozzle was conducted under the following experimental conditions using the apparatus shown in FIG. Airtightness evaluation temperature is the average temperature of the nozzle fitting part when molten steel is poured into the immersion nozzle and filled, and the outer peripheral part is naturally cooled. In addition to the three levels, the three levels of the average temperature of the nozzle fitting portion when the outer peripheral portion of the nozzle is gas-cooled were implemented. The time when the air flow rate of the nozzle was 0.2 liter / min or less was used as the evaluation value of the stability of airtightness, and the results of Table 3 were obtained. The effectiveness of the method was confirmed. By the way, the average temperature of the nozzle fitting part when molten steel is poured and filled inside the immersion nozzle and the outer peripheral part is naturally cooled is 1200 ° C in the fitting part in the furnace 10.
Corresponds to keeping warm. Further, the average temperature of the nozzle fitting portion when the outer peripheral portion of the nozzle is gas-cooled is the case where the fitting portion is kept at 500 ° C. in the furnace 10 to cool the fitting portion with nitrogen gas of 20 liter / min. In 600
By keeping the temperature at 0 ° C., this corresponds to the case where the fitting portion is cooled at 15 liters / min of nitrogen gas. Experimental condition (1) Shape 150 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature 800 ° C. (3) Filling material Material according to the present invention; Boron oxide Comparative material; Amorphous refractory + organic resin (4) Pressure 100 Kg / cm ² (5) Differential pressure between nozzle and atmosphere 200 torr (6) Airtightness evaluation temperature 500 ° C. 600 ° C. 1200
℃

[0034]

[Table 3]

When the filling material according to the present invention is used, when the airtightness evaluation temperature is as low as 500 ° C. and 600 ° C., it is 0.2 liter / liter as compared with 1200 ° C.
The airtightness is stable for a long time of 800 minutes and 600 minutes with a ventilation amount of min. Furthermore, compared with the comparative example, the airtightness is secured for a long time and the stability of the airtightness is excellent. That is, it was confirmed that the fitting method of cooling the outer circumference of the nozzle of the fitting portion after filling and fitting the filling material according to the present invention was superior to other methods.

(Embodiment 4) In order to compare the airtightness after fitting of the immersion nozzle, the case of using the existing filling material 6 and the case of using the filling material 8 according to the present invention were examined. First, the split pouring nozzle, that is, the upper nozzle 1 in FIG.
A fitting model was prepared by combining A and the lower nozzle 1B. Next, the filling material was placed in the fitting portion, and a load was applied to the upper portion of the nozzle at a high temperature in the furnace 10 heated by the burner 9 as shown in FIG. 8 to fit the upper and lower nozzles. after that,
The airtightness evaluation test of the nozzle was conducted under the following experimental conditions using the apparatus shown in FIG. Airtightness evaluation temperature is the average temperature of the nozzle fitting part when molten steel is poured into the immersion nozzle and filled, and the outer peripheral part is naturally cooled. In addition to the three levels, the three levels of the average temperature of the nozzle fitting portion when the outer peripheral portion of the nozzle is gas-cooled were implemented. The time when the air flow rate of the nozzle was 0.2 liter / min or less was used as the evaluation value of the stability of airtightness, and the results of Table 4 were obtained, and the fitting material according to the present invention was used to cool the fitting part. The effectiveness of the method was confirmed. By the way, the airtightness evaluation temperature is 1200 ° C, 500 ° C, 600 ° C, 700 ° C in the furnace 10.
It was kept warm at 800 ° C. 700 ° C. and 800 ° C. correspond to the case of cooling with a nitrogen gas flow of 10 l / min and a nitrogen gas flow of 5 l / min, respectively. Experimental condition (1) Shape 150 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature Changed depending on the amount of refractory powder Comparative example is 700 ° C. (3) Filling material Material according to the present invention: Boron oxide + refractory powder Comparative material; Irregular refractory + organic resin (4) Pressure 100 Kg / Cm ² (5) Pressure difference between nozzle and atmosphere 200 torr (6) Airtightness evaluation temperature 1200 ° C, 500 ° C, 600
℃, 700 ℃ and 800 ℃

[0037]

[Table 4A]

[0038]

[Table 4B]

When the filling material according to the present invention is used, the airtightness evaluation temperature is 500 ° C, 600 ° C or 70 ° C.
When the temperature is as low as 0 ° C. or 800 ° C., the airtightness is secured for a long time and the stability of the airtightness is excellent as compared with the case of 1200 ° C. or as compared with the comparative example. That is, it was confirmed that the fitting method of cooling the outer circumference of the nozzle of the fitting portion after the filling material according to the present invention was fitted and fitted was excellent.

(Embodiment 5) Next, in a two-strand casting of low carbon aluminum killed steel which is cast while controlling the amount of molten metal poured from the tundish into the mold by a stopper device, one strand has a non-standard refractory material as a comparative material. And a conventional filling material composed of an organic resin, and a split type pouring nozzle in which boron oxide as a filling material according to the present invention is applied to the other strand, respectively, and conditions such as casting size and casting speed are aligned together. As a precharge, a comparative experiment of pouring amount control by actual molten metal casting was conducted. The purpose of this experiment is to compare and investigate the increase in flow resistance due to the gas suction from the fitting part of the split type pouring nozzle, and the influence on the pouring amount control when the secondary meniscus is formed in the nozzle. is there. As the evaluation method, the judgment was made by the time-dependent characteristics of the opening change of the stopper 4 which controls the pouring amount of each nozzle. Further, the same experiment was carried out for the case of using the composition according to the present invention in which the filling material was a mixture of boron oxide and refractory powder as a post-charge.

The results are shown in FIG. Regarding the pre-charging, when the conventional filling material is used, the opening degree of the stopper 4 periodically changes, and the average opening degree tends to gradually increase with time. On the other hand, in the case of the present invention, no periodic fluctuation of the stopper opening degree is observed, and the average opening degree is slightly increased, which is not a particular problem.
Furthermore, when the composition according to the present invention in which boron oxide and refractory powder were mixed as the filling material by post-charging, the same results as in FIG. 9 were obtained, and the periodic fluctuation of the stopper opening degree was completely observed. There is no particular problem because the average opening is slightly increased.

(Embodiment 6) Filling material for fitting part of long nozzle
Conventional filling materials to compare airtightness with respect to materials
With 6 and with the filling material according to the invention
And examined. First, the split pouring nozzle,
1 upper nozzle 1A and lower nozzle 1B combination or
Combination of 1C and 1D of 3 and combination of 3C and 3D of FIG.
A fitting model by setting was created. Next, fill material in the fitting part
In the furnace 10 where the material is placed and heated by the burner 9 as shown in FIG.
At a high temperature with a load applied to the top of the nozzle.
The lower nozzle was fitted. After that, evaluate the airtightness of the nozzle
The test was conducted using the apparatus of FIG. 8 under the following experimental conditions.
The mating temperature is such that the filling material will not flow out if the mating surface is flat.
The temperature was set so that it would not occur. Airtightness evaluation temperature is within the long nozzle
When molten steel is poured into the
The average temperature of the nozzle fitting portion was used. Airtightness evaluation is stable
The ventilation amount and time at the time were used as evaluation values, and the results in Table 5
Then, the effectiveness of the present invention was confirmed. In addition, 11 in FIG.
A flow meter, 12 is a vacuum gauge. Experimental condition (1) Shape 150 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature 600 ° C. (3) Filling material Material according to the present invention; boron oxide Comparative material; amorphous refractory + organic resin (4) Pressure 100 Kg / cm²  (5) Pressure difference between nozzle and atmosphere 400 torr (6) Airtightness evaluation temperature 1200 ° C

[0043]

[Table 5]

If the filling material according to the invention is used,
Compared with the case where an amorphous refractory and a resin are used as the filling material as in the comparative example, the ventilation amount is as small as one tenth, and the airtightness is good for a long time. Therefore, it is confirmed that the filling material of the present invention is superior.

(Embodiment 7) Regarding the filling material of the fitting portion of the long nozzle, in order to compare the airtightness, the case of using the conventional filling material 6 and the case of using the filling material according to the present invention were examined. First, a fitting model using a combination of the split type pouring nozzle, that is, the upper nozzle 1A and the lower nozzle 1B in FIG. 1 was produced. Next, the filling material is placed on the fitting portion, and the filling material shown in FIG.
As described above, the upper and lower nozzles were fitted with each other while heating with the burner 9 and in the furnace 10 at a high temperature with a load being applied to the upper portion of the nozzle. After that, an airtightness evaluation test of the nozzle was performed under the following experimental conditions using the apparatus shown in FIG. In the evaluation of airtightness, the ventilation amount and time at the time of stability were used as evaluation values, and the results of Table 6 were obtained to confirm the effectiveness of the present invention. Experimental conditions (1) Shape 200 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature Varies depending on the amount of refractory powder (3) Filling material Material according to the present invention: Boron oxide + refractory powder Comparative material; Irregular refractory + organic resin (4) Pressure 100 Kg / cm ² (5 ) Pressure difference between nozzle and atmosphere 400 torr (6) Airtightness evaluation temperature 1200 ° C

[0046]

[Table 6A]

[0047]

[Table 6B]

When the filling material according to the invention is used,
Compared to the case where an amorphous refractory and a resin are used as the filling material as in the comparative example with an air flow rate of 0.4 liter / min, or when the filling material of boron oxide is less than 90% by weight and the balance is refractory powder. It is confirmed that the filling material of the present invention is superior because the air flow rate is as small as 1/10 as compared with the case where it is used.

(Embodiment 8) In order to compare the airtightness after fitting of the long nozzle, the case of using the existing filling material 6 and the case of using the filling material according to the present invention were examined. First, the split pouring nozzle, that is, the upper nozzle 3 in FIG.
A fitting model was prepared by combining C and the lower nozzle 3D. Next, the filling material was placed in the fitting portion, and as shown in FIG. 8, the upper and lower nozzles were fitted in a furnace 10 heated by a burner 9 under a high temperature with a load being applied to the upper portion of the nozzle. After that, an airtightness evaluation test of the nozzle was performed under the following experimental conditions using the apparatus shown in FIG. The airtightness evaluation temperature is the average temperature of the nozzle fitting part when molten steel is poured and filled inside the long nozzle and the outer peripheral part is naturally cooled. In addition to the level of
Three levels, two levels when the average temperature of the nozzle fitting portion corresponding to the case where the outer peripheral portion of the nozzle was gas-cooled, were used. Aeration rate of nozzle is 0.4 liter / min
The following time was taken as the evaluation value of the airtight stability, and the results of Table 7 were obtained from this to confirm the effectiveness of the fitting method of cooling the fitting part using the filling material according to the present invention. Experimental conditions (1) Shape 200 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature 800 ° C. (3) Filling material Material according to the present invention; Boron oxide Comparative material; Amorphous refractory + organic resin (4) Pressure 100 Kg / cm ² (5) Differential pressure between nozzle and atmosphere 400 torr (6) Airtightness evaluation temperature 500 ° C. 600 ° C. 1200
℃

[0050]

[Table 7]

When the filling material according to the present invention is used, when the airtightness evaluation temperature is as low as 500 ° C. and 600 ° C., 0.4 liter /
Airtightness is secured for a long time of 800 minutes and 600 minutes with a ventilation amount of min. Furthermore, compared with the comparative example, the airtightness is secured for a long time and the stability of the airtightness is excellent. That is, it was confirmed that the fitting method of cooling the outer circumference of the nozzle of the fitting portion after filling and fitting the filling material according to the present invention was superior to other methods.

(Embodiment 9) In order to compare the airtightness after fitting of the long nozzle, the case of using the existing filling material 6 and the case of using the filling material according to the present invention were examined. First, the split pouring nozzle, that is, the upper nozzle 1 in FIG.
A fitting model was prepared by combining A and the lower nozzle 1B. Next, the filling material was placed in the fitting portion, and the upper and lower nozzles were fitted in a furnace 10 heated by a burner 9 at a high temperature as shown in FIG. After that, an airtightness evaluation test of the nozzle was performed under the following experimental conditions using the apparatus shown in FIG. The airtightness evaluation temperature is the average temperature of the nozzle fitting part when molten steel is poured and filled inside the long nozzle and the outer peripheral part is naturally cooled. In addition to the level of
Three levels, that is, two levels when the average temperature of the nozzle fitting portion when the outer peripheral portion of the nozzle was gas-cooled, were implemented. The time when the air flow rate of the nozzle was 0.4 liter / min or less was used as the evaluation value of the stability of airtightness.
Based on the above results, the effectiveness of the fitting method of cooling the fitting part using the filling material according to the present invention was confirmed. Experimental conditions (1) Shape 200 mm outer diameter x 80 m inner diameter
m (2) Fitting temperature Changed depending on the amount of refractory powder Comparative example is 700 ° C. (3) Filling material Material according to the present invention: Boron oxide + refractory powder Comparative material; Irregular refractory + organic resin (4) Pressure 100 Kg / Cm ² (5) Pressure difference between nozzle and atmosphere 400 torr (6) Airtightness evaluation temperature 1200 ° C, 500 ° C, 600
℃, 700 ℃ and 800 ℃

[0053]

[Table 8A]

[0054]

[Table 8B]

When the filling material according to the present invention is used, the airtightness evaluation temperature is 500 ° C, 600 ° C or 70 ° C.
When the temperature is as low as 0 ° C. or 800 ° C., the airtightness is secured for a long time and the stability of the airtightness is excellent as compared with the case of 1200 ° C. or as compared with the comparative example. That is, it was confirmed that the fitting method of cooling the outer circumference of the nozzle of the fitting portion after the filling material according to the present invention was fitted and fitted was excellent.

(Embodiment 10) Next, in casting of low carbon aluminum killed steel which is poured from a ladle into a tundish by a stopper device, a conventional filling material composed of an amorphous refractory as a comparative material and an organic resin, or A divided type pouring nozzle to which boron oxide as a filling material according to the present invention was applied was arranged, and the conditions such as the casting size and the casting speed were made uniform for each, and a comparative experiment by actual casting was conducted. The purpose of this experiment is to compare and investigate the influence of gas suction from the fitting part of the split type pouring nozzle on the quality of steel. As an evaluation method, molten steel was sampled from the tundish at the time of casting, and it was judged by the nitrogen concentration in the steel after solidification. Further, the same experiment was carried out when the filling material was the composition of the present invention in which boron oxide and refractory powder were mixed.

The results are shown in FIG. When the conventional filling material is used, the nitrogen concentration becomes 1 over time.
There is a tendency that the concentration gradually increases from 5 ppm. On the other hand, in the case of the present invention, there was no tendency to increase the nitrogen concentration, and it was confirmed that the nitrogen concentration was 5 ppm, which was a low concentration as compared with the case of the comparative material, and the quality was improved. In addition, similar results to those shown in FIG. 9 were obtained in the same experiment conducted for the composition of the present invention comprising the filling material boron oxide and the refractory powder, and in the case of the filling material according to the present invention, Compared with the case, the nitrogen concentration was low and it was confirmed that the quality was improved.

[0058]

As described above, according to the present invention, even if a split type pouring nozzle having a fitting portion is used, a dipping nozzle for continuous casting of metal or a long nozzle is fitted. It is possible to control the amount of molten metal stably without inhaling the outside air from the part. Further, since it is possible to prevent the contamination of the molten metal due to the suction of the outside air, even in the continuous casting of the metal, which requires a highly accurate pouring amount control, the same effect as that of the integrated pouring nozzle having no fitting portion can be exhibited. Further, the yield of the metal plate is improved and the quality is improved.

[Brief description of drawings]

FIG. 1 is a first example of a conceptual view of a pouring nozzle fitting mechanism when the filling material according to the present invention is used in a tundish or ladle having a stopper device.

FIG. 2 is a first example of a conceptual view of a pouring nozzle fitting mechanism when the filling material according to the present invention is used in a tundish or ladle having a sliding nozzle.

FIG. 3 is a conceptual diagram of a pouring nozzle fitting mechanism when a conventional filling material is used in a tundish or ladle having a stopper device.

FIG. 4 is a conceptual diagram of a pouring nozzle fitting mechanism when a conventional filling material is used in a tundish or a ladle having a sliding nozzle.

FIG. 5 is a second example of a conceptual diagram of a pouring nozzle fitting mechanism when the filling material according to the present invention is used in a tundish or ladle having a stopper device.

FIG. 6 is a second example of a conceptual view of a pouring nozzle fitting mechanism when the filling material according to the present invention is used in a tundish or ladle having a sliding nozzle.

FIG. 7A is a cooling device of a pouring nozzle fitting mechanism. (B) is a plan view of the cooling device.

FIG. 8 is a conceptual diagram of an experimental device for evaluating airtightness of a fitting part.

FIG. 9 is a result of a comparative experiment of changes in stopper opening with time.

FIG. 10 shows the results of a comparative experiment of changes over time in nitrogen concentration in steel.

[Explanation of symbols]

1A Tundish or ladle top nozzle 1C Tundish or ladle top nozzle 3C Tundish or ladle top nozzle 1B Tundish or ladle dip nozzle or long nozzle 1D Tundish or ladle dip nozzle or long Nozzle 3D Tundish or ladle dipping nozzle or long nozzle 2A Sliding nozzle device lower plate 2C Sliding nozzle device lower plate 4C Sliding nozzle device lower plate 2B Sliding nozzle device lower plate mating dipping nozzle or long nozzle Immersion nozzles or long nozzles that fit with the lower plate of a 2D sliding nozzle device. No immersion nozzles that fit with the lower plate of a 4D sliding nozzle device. Long nozzle 1 a tundish or ladle 2 recess 3 protrusions and 4 stopper 5 sliding nozzle device 6 filling material 9 burner 10 furnace 11 flow meter 12 vacuum gauge 13 cooling system of a conventional filling material 7 bottom 8 the invention

[Procedure amendment]

[Submission date] April 26, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

As a result, the workability when fitting the nozzle after preheating is that the viscosity of the filling material 8 is 10 ⁴ poi.
If it is se, the fluidity at the time of fitting is good, the fitting is easy, it is easy to handle, and at the same time, in terms of function, the filling material easily flows in the gap of the fitting part and It has been found that uniform filling can be achieved and the airtightness is improved, and that the airtightness can be secured for a long time. Further there a viscosity of 10 ⁵ poise, was discovered also that the tightness can be achieved also improved on features that can be secured over a more extended period of time.

Claims (6)

[Claims] 1. When continuously casting a slab from molten metal,
At the fitting between the upper nozzle of the ladle bottom or the lower plate of the sliding nozzle device and the long nozzle connected below it, or at the upper nozzle of the tundish bottom or the lower plate of the sliding nozzle device and below it. A filling material to be used for filling a fitting portion between the immersion nozzle connected to the above and the immersion nozzle, the viscosity of which is 10 ⁴ poise and 10 ⁵ p within a temperature range from room temperature to the temperature of the molten metal.
A fitting part filling material in a nozzle for continuous casting of metal, characterized in that it contains an oxide having a temperature of becoming oise. 2. The fitting portion filling material for a metal continuous casting nozzle according to claim 1, wherein the oxide is boron oxide or an oxide containing boron oxide. 3. The oxide containing boron oxide contains 90% boron oxide.
3. A nozzle for continuous casting of metal according to claim 2, wherein the composition is a composition containing 10% by weight or less of powder of alumina, silica, or zirconia having a particle size of 1% by weight or more and the balance of 10% by weight or less. Filling material for mating parts. 4. When continuously casting a slab from molten metal,
At the fitting between the upper nozzle of the ladle bottom or the lower plate of the sliding nozzle device and the long nozzle connected below it, or at the upper nozzle of the tundish bottom or the lower plate of the sliding nozzle device and below it. The viscosity of 10 ⁴ pois in the temperature range from room temperature to the temperature of the molten metal at the fitting part between the immersion nozzle connected to the
and a fitting material containing an oxide having a temperature of 10 ⁵ poise, and fitting the fitting material, and then cooling the outer circumference of the nozzle of the fitting portion, fitting in a nozzle for continuous casting of metal Method. 5. The fitting method in a nozzle for continuous casting of metal according to claim 4, wherein the oxide is boron oxide or an oxide containing boron oxide. 6. The oxide containing boron oxide contains 90% boron oxide.
6. A nozzle for continuous casting of metal according to claim 5, wherein the composition is a composition containing 10% by weight or less of powder of at least 1% of alumina, silica, and zirconia having a particle size of 1 μm or less by weight and the balance being 1 μm or less. Mating method in.