JP4121048B2 - Ladle nozzle filler evaluation method and ladle - Google Patents

Description

【００１６】
第１表に示す材質を使用することにより、溶鋼を受鋼しても保持部１０が浮上せずに、またスラグ排出時に落下することなく敷部８に保持部１０を固定することが出来る。
【００１７】
【発明の効果】
本発明による取鍋ノズル充填材の評価方法及び取鍋は、以上のように構成されているため、次のような効果を得ることができる。
すなわち、実際の使用個所とほぼ等しい溶鋼の静圧を受けた条件でノズル充填材の試験ができるので焼結性や地金の差し込み状況を正しく評価でき、この試験で評価した材料を使うことにより羽口におけるノズルの自然開口率が従来よりも向上し、従来よりも取鍋の操業効率を大幅に向上させることができる。
【図面の簡単な説明】
【図１】本発明による評価用のノズル充填材を取鍋に設けた状態を示す断面図である。
【図２】図１の要部を示す平面図である。
【符号の説明】
１ ノズル充填材
２ 取鍋
３ 升レンガ
４ 上ノズル
５ スライディングノズル装置
６ 上プレート
７ 下プレート
８ 敷部
９ 評価用のノズル充填材
１０ 保持部
１１ 不定形材
３０ 溶鋼流出用ノズル[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ladle nozzle filler evaluation method and ladle, and in particular, sintering of a nozzle filler to be filled in a nozzle hole for controlling the flow rate of molten metal installed in a molten steel receiving vessel such as a ladle. The present invention relates to a test method for evaluating properties such as hot water resistance and hot water resistance so as to be substantially the same as in actual use.
[0002]
[Prior art]
In general, a molten metal flow rate control device installed in a molten steel receiving vessel such as a ladle, for example, a sliding nozzle device 5 is generally composed of an upper nozzle 4, an upper plate 6, a lower plate 7, and a lower nozzle 4A as shown in FIG. And is widely used to adjust or stop the amount of molten metal flowing out by opening and closing the lower plate 7.
For example, when the hot water is received in the ladle, the upper nozzle 4 and the upper plate 6 of the sliding device 5 are at a lower temperature than the molten steel, so that the injected molten metal is cooled and solidified by contact with the molten steel. May not leak. Therefore, in order to solve this problem, the nozzle hole is filled with a filler sand mixed with silica sand containing SiO ₂ as a main component and feldspar mainly containing alkali, or a filler mixed with chromium ore and SiO _2. JP-A-7-307663 discloses a method in which when the nozzle is opened, the filler is dropped and subsequently the molten metal is dropped. When the nozzle is opened, the static pressure of the molten steel is disclosed. Flowing naturally is called natural opening.
[0003]
Even if the filler is filled in the nozzle hole, overfilling may occur due to the filler being in contact with the hot molten steel for a long time, or the molten metal may be deeply inserted into the filler. If it happens, it may not spontaneously open.
Therefore, it is necessary to select a filler that matches the operating conditions (molten metal temperature, molten metal time, etc.) when using the filler. For example, if a filler with a low sintering temperature is used for the operating conditions, it will be excessive. When sintering was performed and a material having a high sintering temperature was used, molten metal was inserted, and selection of this material was very difficult.
[0004]
[Problems to be solved by the invention]
Therefore, selection of a filler that matches the operating conditions has often been inferred from experience through trial and error. Therefore, as an experimental evaluation method of the filler, for example, in Japanese Patent Laid-Open No. 62-286665, the filler is put in a container having an opening on the side, and the container is immersed in molten metal, and the opening is inserted through the opening. The method of evaluating the sinterability and hot water resistance of the filler by repeating the inflow and outflow of the molten metal, and further the filler in a refractory container whose lower end is opened in JP-A-9-54077 The lower end opening is closed with an easily soluble metal thin foil, the lower part is immersed in molten metal in a vertical direction for a predetermined time, and then pulled up to give a temperature gradient in the filler. There are methods for evaluating the sinterability and hot water resistance of fillers.
However, under actual operation, a nozzle filler is provided at the bottom of the ladle containing the molten metal, and it is in a state where it has been subjected to the static pressure of the molten metal. It was impossible to test under the same conditions.
[0005]
An object of the present invention is to provide a ladle nozzle filler evaluation method and ladle capable of comparatively evaluating the characteristics of the filler under the same conditions as the actual operating conditions in which the filler is used. And
[0006]
[Means for Solving the Problems]
In the ladle nozzle filler evaluation method according to the present invention, the ladle laying portion is provided with a holding portion at a position different from the molten steel outflow nozzle, and the holding portion holds the evaluation nozzle filler, and the ladle After the molten steel is poured into the holding part, the nozzle filler in the holding part is recovered, and the sintering state of the nozzle filler and the penetration state of the metal are determined, and the holding part spreads downward. It is a method with a tapered shape with a material made of iron or refractory with excellent volume stability between hot, and as a method of building the holding part, volume stability from hot to cold This is a method of forming a holding portion on the laying portion using an amorphous refractory mainly composed of Al ₂ O ₃ or Al ₂ O ₃ -spinel having excellent properties, and the holding portion is directly subjected to a steel flow. It is a method that is used by providing a part of the floor portion .
Further, the ladle according to the present invention has a holding portion provided at a position different from the nozzle for flowing out the molten steel in the laying portion, and is configured to hold the nozzle filler for evaluation in the holding portion. The holding portion is configured to have a tapered shape that spreads downward.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a ladle nozzle filler evaluation method and ladle according to the present invention will be described with reference to the drawings.
FIGS. 1 and 2 show a ladle 2 according to the present invention. At a position deviated from the center of the laying portion 8, a brick 3, an upper nozzle 4, and a sliding nozzle device 5 forming a molten steel outflow nozzle 30 are formed. An upper plate 6, a lower plate 7, and a lower nozzle 4 </ b> A are provided. A holding portion 10 having a tapered cylindrical shape extending downward is fixed by an indefinite shape material 11 at a position shifted from the center of the upper surface of the floor portion 8. Has been. The molten steel outflow nozzle 30 composed of the brick 3 and the upper nozzle 4 is filled with the nozzle filler 1, and the holding portion 10 is filled with the nozzle filler 9 for evaluation. The holding portion 10 is not limited to the above-described cylindrical shape, and a hole can be formed by scraping the laying portion 8 downward as indicated by a dotted line. Moreover, the position of this holding | maintenance part 10 is comprised so that it may become the position shifted | deviated from the steel receiving position 20 at the time of receiving molten steel, as shown in FIG.
[0008]
That is, according to the present invention, the holding part 10 is formed in the laying part 8 of the ladle 2 at a position different from the molten metal outflow nozzle 30, and the nozzle filling material 9 for evaluation is put into the holding part 10, and actually After the molten steel is received and injected by continuous casting, the nozzle filler 9 remaining in the holding part 10 is recovered, so that the temperature equivalent to the nozzle filler 1 filled in the molten steel outflow nozzle 30 is obtained. This is an evaluation method capable of investigating the sintering state and the molten metal insertion state of the nozzle filler 9 subjected to static pressure.
In the method for evaluating a nozzle filler in the present invention, an evaluation test is performed, for example, with the configuration shown in FIG. That is, the holding part 10 of the laying part 8 of the ladle 2 may be any number as long as the molten metal is dropped from the converter into the ladle 2 as long as the molten steel is not directly hit, and spreads from the upper part to the lower part. The nozzle filling material 9 remaining in the holding portion 10 is dropped when the ladle 2 is turned over in order to discharge the slag in the ladle 2 after the end of pouring by continuous casting with this taper. Do not.
[0009]
Furthermore, in order to fix the holding | maintenance part 10 to the laying part 8 of the pan 2, the refractory indefinite shape material 11 is used. The amorphous material 11 to use a from between 1700 ° C. heat room temperature (20 ° C.) the expansion and contraction amount of over the small A1 ₂ O ₃ or A12 ○ 3- spinel. If a refractory having a large hot expansion, such as SiO ₂ or MgO, is used, the refractory of the floor portion 8 hardly expands in the lateral direction, whereas an indefinite shape material for fixing the holding portion. 11 expands, and due to this difference in expansion, the bond between the laying portion 8 and the holding portion 10 is peeled off. As a result, the holding portion 10 floats in the molten steel receiving steel, and the holding portion 10 falls when the slag is discharged. Arise.
[0010]
Accordingly, the nozzle filling material 9 for evaluation is filled in the holding part 10 fixed to the laying part 8 of the ladle 2, the molten steel is received under actual operation, and thereafter, under high temperature and high pressure until the pouring is completed in continuous casting. Contact with molten metal. After discharging the slag, the nozzle filler 9 is collected, and the state of sintering and the state of intrusion of molten metal are examined to evaluate the material.
As the evaluation of the nozzle filler 9, the metal insertion depth from the molten steel contact surface, the thickness and the sintered density of the sintered layer of the material from the molten steel contact surface are measured, and the appearance is visually observed and evaluated.
By performing the nozzle filler evaluation method according to the present invention, an experiment can be performed under the same conditions as the state in which the molten steel outflow nozzle 30 is filled. Therefore, the state of penetration of molten steel into the nozzle filler 9 is the conventional evaluation method so far. This makes it possible to select the nozzle filler 9 that appears more remarkably and is more suitable for actual operation.
[0011]
The nozzle filling material 1 of the embodiment is originally filled from the straw brick 3 which is a tuyere to the upper plate 6, and when the molten metal is poured from the ladle 2 into the tundish (not shown) in continuous casting, the lower plate 7 is used. The nozzle filler 1 is dropped just by opening, and the molten metal is filled in the molten steel outflow nozzle 30 aiming at the molten metal flowing into the tundish. However, if the nozzle filler 1 is oversintered due to contact with the molten steel for a long time, or if the molten steel is inserted deep inside the nozzle filler 1, the filling is performed even if the lower plate 7 is opened. Since the material does not fall, a phenomenon that the molten steel does not flow out occurs.
[0012]
Therefore, as a characteristic required for the nozzle filler 1, it is required not to oversinter even in contact with molten steel for a long time. In order to prevent oversintering, measures such as applying Cr ₂ O ₃ or MgO having a high melting point to the nozzle filler 1 or making the particle size of the nozzle filler 1 coarse can be considered. If such a measure is advanced, this time, when the molten steel is received, the molten steel is inserted deep inside the nozzle filler 1. Therefore, it is necessary to select the nozzle filler 1 having a material and particle size that match each operating condition.
[0013]
As a method for selecting a nozzle filler that matches each operating condition, the present invention uses a structure in which the holding portion 10 is placed on the laying portion 8 of the ladle 2 described above and fixed with an indefinite shape material 11.
This holding part 10 is placed at a position away from the place where the molten steel falls when the steel is discharged from the converter. The shape of the holding part 10 is 100 mm in height from the top when measuring the sinterability of the nozzle filler 9 and the depth of the metal insertion, A steel one having a diameter of 250 mm and a lower diameter of 300 mm was used. Furthermore, in order to prevent the material from flowing out from the steel flow in the ladle at the time of steel output by filling the nozzle filler 9, a lid (not shown) that is melted away by the heat of the molten steel can be used.
[0014]
Table 1 shows the material property table of the irregular shape material used when fixing the holding portion 10 to the laying portion 8. As the irregular shaped material, a Hi-Al ₂ O ₃ quality patching material having a small thermal expansion coefficient was used.
[0015]
[Table 1]

[0016]
By using the material shown in Table 1, the holding portion 10 can be fixed to the laying portion 8 without rising when the molten steel is received and without falling when the slag is discharged.
[0017]
【The invention's effect】
Since the ladle nozzle filler evaluation method and ladle according to the present invention are configured as described above, the following effects can be obtained.
In other words, the nozzle filling material can be tested under conditions where static pressure of the molten steel is almost equal to the actual use location, so that the sinterability and the insertion state of the metal can be evaluated correctly, and by using the materials evaluated in this test The natural aperture ratio of the nozzle at the tuyere is improved than before, and the operation efficiency of the ladle can be greatly improved than before.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a state in which a nozzle filler for evaluation according to the present invention is provided in a pan.
FIG. 2 is a plan view showing a main part of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Nozzle filler 2 Ladle 3 Brick 4 Upper nozzle 5 Sliding nozzle apparatus 6 Upper plate 7 Lower plate 8 Laying part 9 Nozzle filler 10 for evaluation 10 Holding part 11 Indeterminate material 30 Molten steel outflow nozzle

Claims (6)

A holding part (10) is provided at a position different from the molten steel outflow nozzle (30) in the ladle part (8) of the ladle (2), and the nozzle filler (9) for evaluation is provided in the holding part (10). Hold and collect the nozzle filler (9) in the holding part (10) after pouring molten steel into the ladle (2), the sintering state of this nozzle filler (9) and the penetration state of the metal The evaluation method of the ladle nozzle filler characterized by determining. The ladle according to claim 1, wherein the holding portion (10) has a tapered shape which extends downward and is made of iron or a refractory material having excellent volume stability between heat. Evaluation method of nozzle filler. The method for construction of the holding portion (10), hot Al ₂ O ₃ or Al ₂ O ₃ has excellent volume stability toward cold from - the bottom part using a monolithic refractory mainly containing spinel The method for evaluating a ladle nozzle filler according to claim 1 or 2, wherein a holding portion is formed. The ladle nozzle filler evaluation according to any one of claims 1 to 3, wherein the holding portion (10) is used by being provided in a part of the laying portion (8) which is not directly exposed to the steel flow. Method. The laying part (8) has a holding part (10) provided at a position different from the molten steel discharge nozzle (30), and the evaluation nozzle filler (9) is held in the holding part (10). A ladle characterized by that. The ladle according to claim 5, wherein the holding portion (10) is formed in a taper shape extending toward the lower side.

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