JP2003025060A - Combined sealing member in nozzle joining part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combined sealing member in a nozzle joining part which can hold liquid tightness having high reliability in good yield and is suitable to a production of a high quality cast product, etc. SOLUTION: This combined sealing member in the nozzle joining part is provided with a first annular zone 6 contacting with molten and a second annular zone 7 surrounded and integrated with the first annular zone 6 in the same plane, and the first annular zone 6 is constituted of a corrosion resistance and fire proof material having >=1400 deg.C softening temperature, and the second annular zone 7 is constituted of the fire proof material having 600-1100 deg.C softening temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal member for a nozzle joint when supplying molten metal to a mold or the like.

[0002]

2. Description of the Related Art In the present situation where secondary processing in a ladle and continuous casting are generalized, a slide gate device with an immersion nozzle is used for controlling the flow rate of molten metal (molten metal), for example. . In order to configure this slide gate device, a seal member for preventing gas seal is often used as an indispensable fire resistant member at the nozzle joint joint.

[0003] Here, a slide gate device in which a dipping nozzle installed at the tap of a molten steel container is joined, usually, two or three plates having a molten metal outlet hole are combined in a stack to form a relative structure. It is configured such that the flow rate of the molten metal can be controlled by shifting the outflow hole of each slide plate by the dynamic sliding. Further, the molten metal whose flow rate is controlled is supplied to a mold through, for example, an immersion nozzle, and required casting is performed.

FIG. 4 is a sectional view showing a schematic structure of a slide gate device in which an immersion nozzle is joined. In FIG. 4, 1 is an upper fixed plate facing the molten metal outlet of the molten metal container, 2 is a slide plate facing the molten metal outlet hole 1a of the upper fixed plate 1, and 3 is a molten metal outlet hole 2a of the slide plate 2. The lower fixing plate 4 facing the immersion nozzle 4 facing the molten metal outflow hole 3a of the lower fixing plate 3 is interposed between the immersion nozzle 4 and the lower fixing plate 3 to form a liquid-tight connection part. It is a sheet-like packing (sealing member) made of refractory material. The sheet-like packing 5 is also inserted between the connection surfaces of the upper fixed plate 1 to the molten metal discharge port of the molten metal container.

In the above-mentioned laminated slide gate device, the upper and lower plates 1 and 3 are fixed plates, and one slide plate 2 can slide between the fixed plates 1 and 3.
Moreover, it adopts a liquid-tight arrangement. Then, by sliding the slide plate 2, the molten metal outflow holes 1a, 2a,
3a is slid to control the flow rate and supplied to the mold through the immersion nozzle 4. Therefore, the slide gate plates 1, 2 and 3 have physical effects such as rapid thermal shock and wear due to the molten metal flow, as well as chemical erosion effects (corrosion) due to the molten metal and molten slag, and further the chemical action. The material is selected in consideration of the erosion effect (erosion) in which the physical action and the physical action are combined. It should be noted that a paste-based coating film such as mortar may be formed to make the joint liquid-tight or seal, but the handling operation becomes complicated as compared with the case of the sheet packing 5.

Corresponding to the above functions, the slide gate plates 1, 2 and 3 are made of alumina-carbon which is excellent in slidability, wear resistance and strength against pressure, corrosion resistance and erosion resistance. The material system is composed of the alumina-zirconia-carbon material system.
The alumina-zirconia-carbon material system is widely used in the steel industry because it has the most stable durability.

On the other hand, the sheet-like packing 5 is made of a refractory material having a high melting point or a refractory material having a low melting point as a raw material in accordance with the requirements such as liquid tightness. Here, examples of the high melting point refractory material include, for example, a thin plate-shaped molded article containing alumina-silica as a main component, and examples of the low melting point refractory material include low melting point ceramics and a glass-based molded article. Can be mentioned. In addition, these sheet-like packings 5
In any case, the molded body contains an organic or resinous binder, etc., and the organic or resinous binder is volatilized and the refractory material is sealed by the heat of the molten metal in the inserted state.

[0008]

However, the following disadvantages are recognized in practical use in the slide gate device in which the immersion nozzle is joined. For example, the sheet-like packing 5 inserted on the connection surface of the upper fixed plate 1 with respect to the molten metal discharge port of the molten steel container and the connection surface of the immersion nozzle 4 with respect to the lower fixed plate 3 may not sufficiently fulfill the required functions. .

That is, in the case of the sheet-like packing 5 made of a refractory material having a high melting point, although the smoothness of the surfaces to be connected to each other is ensured, it is the actual situation that a minute gap is likely to be formed on the contact surface. Is. Here, if a minute gap is formed, the molten metal leaks from this gap. Further, when the inside of the immersion nozzle 4 is in a depressurized state due to the action of the molten metal flow, external air is drawn from the gap, which causes inconvenience such as oxidation of the molten metal.

On the other hand, in the case of the sheet-like packing 5 made of a low melting point refractory material, the molten metal is apt to cause thermal damage, so that so-called molten metal leakage is likely to occur. That is, in the case of a low-melting-point refractory material, it is easy to fill fine gaps due to the thermal softening property, and it is possible to temporarily secure good liquid tightness. But,
Since heat deterioration and flow progress in a continuous use process, there is a problem that the shield function is easily impaired, and phenomena such as leakage of hot water and drawing of outside air occur.

As described above, in the construction of the slide plate device in which the immersion nozzle is joined, the sealing means for maintaining the liquid tightness of the connected portion is the operation of attachment / detachment / assembly by inserting the sheet packing. Alternatively, it has an advantage of greatly simplifying operations such as attachment / detachment / replacement. On the other hand, however, the safety of the work environment may be impaired due to the occurrence of hot water leaks. Furthermore, since there is concern that the quality of the cast product may deteriorate due to the oxidation of the molten metal, the development of more practical and effective means is awaited.

The present invention has been made in view of the above circumstances, and has a composite seal of a nozzle joint portion, which has a high yield, maintains a highly reliable liquid-tightness, and is suitable for manufacturing a high-quality cast product. The purpose is to provide members.

[0013]

According to a first aspect of the present invention, a first annular region that contacts molten metal and a second annular region that surrounds and integrates the first annular region in substantially the same plane. And a first annular region made of a corrosion-resistant refractory material having a softening temperature of 1400 ° C. or higher, and a second annular region made of a refractory material having a softening temperature of 600 to 1100 ° C. It is a composite seal member for a nozzle joint part to be used.

According to a second aspect of the present invention, in the composite seal member for a nozzle joint according to the first aspect, the planar annular width ratio of the substantially concentric first annular region and the second annular region is from 1: 1.
It is characterized by having 5: 1.

According to a third aspect of the present invention, in the composite seal member for a nozzle joint according to the first or third aspect, the first annular region and the second annular region have an external ratio of 10 to 20% by mass of organic matter. Or containing a resinous binder.

In the first to third aspects of the present invention, the first annular region that comes into contact with the molten metal is, for example, the molten metal outflow hole portion and the connecting surface portion adjacent to the molten metal outflow hole portion, and specifically, the annular sheet. It corresponds to the inner area of the packing. That is, in the configuration of the slide gate device in which the immersion nozzle is joined, the annular sheet-like packing inserted between the fixed plate to be connected is connected to the molten metal outflow hole portion of the fixed plate, and the central portion forming the molten metal flow path. The side region is made of a refractory material having high corrosion resistance such as alumina, zirconia, zirconia-based ceramics such as zirconia-alumina, siliceous ceramics, alumina, magnesia / spinel ceramics and a softening temperature of 1400 ° C. or higher.

Incidentally, zirconia-based ceramics, etc.
For example, it is preferable to use particles partially stabilized by adding calcium oxide, yttrium oxide, or the like as a material. Further, the first annular region may be a pressure-molded body (unsintered body) containing an organic binder component or a sintered body. Here, in the case of the pressure-molded body, in the use state in which the molten metal is flowed, the form of the sintering progresses by the heat from the molten metal.

In the first to third aspects of the present invention, the second annular region surrounds the first annular region in the same plane and surrounds the first annular region. In other words, the ring-shaped first annular region has substantially the same thickness. A configuration in which one annular region and a ring-shaped second annular region are fitted and integrated is adopted. Here, the refractory material having a low softening temperature forming the second annular region has a softening temperature of 600.
Ceramics, glasses, or a glass-ceramics mixed system at ˜1100 ° C. Specifically, it is a mixed system of low-melting ceramics such as feldspar or loach and an inorganic binder such as frit or sodium silicate, and is usually formed as a green body to which an organic system such as vinyl acetate resin is added. To be done.

In the first to third aspects of the present invention, the first annular region and the second annular region are integrated with each other by, for example, an annular molded body made of a refractory material having a low melting point and an annular body made of a refractory material having a high melting point. This is performed by adopting a configuration in which a molded body or a sintered body is fitted. In addition, in this fitting type integration,
In the case of molded bodies, after fitting, the main surface is pressed to ensure secure fitting and flattening. In addition, when fitting a sintered compact, it is easier and more intimately integrated by adopting the structure of fitting and tightening by utilizing the heat shrinkability of the annular molded body made of refractory material with a low melting point. Can be converted.

It is also possible to adopt a structure in which the fitting surfaces of the first annular region and the second annular region are stepped or have uneven surfaces, and the integration of these is promoted by their engagement. Further, between the first annular region and the second annular region, a refractory material having a lower melting point than the refractory material forming the first annular region and a higher melting point than the refractory material forming the second annular region. The third annular region made of a material may be interposed.

In the first to third aspects of the invention, the inner diameter and the outer diameter of the first annular region and the second annular region are set according to the purpose of use and the mode of use of the refractory member. For example, in a sliding nozzle device, in the case of a sheet-like packing that seals the connection between the lower fixing plate and the immersion nozzle, the inner diameter of the first annular region is about the same as the molten metal flow diameter of the immersion nozzle, and The outer diameter of the annular region (sheet-like packing) is set to be approximately the same as the outer diameter of the end surface of the immersion nozzle with respect to the fixed platen.

Here, the ratio of the difference between the outer diameter and the inner diameter (plane width) of the first annular area and the difference between the outer diameter and the inner diameter of the second annular area (plane width) is the same as that of the fixed plate. It is preferable to set it in consideration of the temperature of the connection portion with the immersion nozzle. For example, when the temperature of the connection portion exceeds 1100 ° C., 2: 1 to
5: 1 or below 1100 ° C,
Set about 1: 1 to 2: 1.

According to the first to third aspects of the invention, the region in contact with the molten metal is made of a corrosion-resistant high-melting-point refractory material, and the outer peripheral region is integrally surrounded by the low-melting-point refractory material in a plane. There is. Therefore, the molten metal (molten metal) that contacts
On the other hand, while exhibiting excellent corrosion resistance and the like, the softening / filling property of the outer peripheral edge region ensures a dense filling / sealing of the outer peripheral edge region of the connected portion, thus exhibiting a highly durable shield function.

That is, the region in contact with the molten metal exhibits the required function mechanically and chemically due to excellent heat resistance and corrosion resistance, while the region surrounding and integrating this region is heated by the molten metal. It easily softens or exhibits flowability / fillability, and seals the outer peripheral edge region of the connected part without any gap. More specifically, mechanical and chemical deterioration and damage of the seal packing in the connected portion are eliminated, and further, it functions as a fire resistant member capable of reliably forming and securing excellent liquid tightness. Therefore, the reliability and the useful life of the slide gate device used in contact with the molten metal are improved, and the yield and durability are improved.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described below with reference to FIGS. 1 (a), 1 (b), 2 and 3.

(Formation of first annular region)

25% by mass of zirconia particles having a particle diameter of 1 to 0.5 mm and 10% by mass of zirconia particles having a particle diameter of 0.5 to 0.3 mm, each of which is partially stabilized by calcium oxide.
Composition of 65% by mass of zirconia particles having a particle size of less than 0.3 mm (Sample A-1), 10% by mass of zirconia particles having a particle size of 1 to 0.5 mm partially stabilized with calcium oxide, and a particle size of 0. Zirconia particles 20 of 5 to 0.3 mm
Composition of 70% by mass of zirconia particles having a particle size of less than 0.3 mm (Sample A-2), 25% by mass of zirconia particles having a particle size of 1 to 0.5 mm and partially stabilized with yttrium oxide, respectively. 1. 10% by mass of zirconia particles having a diameter of 0.5 to 0.3 mm, 65% by mass of zirconia particles having a particle size of less than 0.3 mm (Sample A-3), and 100 parts by mass of each of the pulp waste liquids. 5 parts by mass are added and kneaded to prepare 3 kinds of zirconia-based mixed soil.

Each of the mixed soils based on the compositions of Samples A-1 to 3 above had an inner diameter of 40 to 70 mm and an outer diameter of 80 to 150.
1 mm and a thickness of 2 to 6 mm, which is press-molded into an annular molded body, and FIG.
Three types of sheet-shaped annular molded bodies, each of which has a schematic plan view shown in (a), were manufactured.

(Formation of second annular region)

20% by mass of feldspar particles having a particle size of 1 to 0.5 mm, 10% by mass of feldspar particles having a particle size of 0.5 to 0.3 mm, 40% by mass of feldspar particles having a particle size of less than 0.3 mm, and a particle size of 0. 3m
4.5 parts by mass of pulp waste liquid is added to 100 parts by mass of a composition of 30% by mass of sodium silicate particles of less than m and kneaded to prepare a feldspar / sodium silicate mixed soil. This feldspar / sodium silicate mixed soil has an inner diameter of 80 to 150 mm and an outer diameter of 90 to 20.
A ring-shaped molded body having a thickness of 0 mm and a thickness of 2 to 6 mm was pressure-molded to produce a sheet-shaped circular molded body having a schematic plan view shown in FIG.

(Production of Sheet-like Packing) The first annular region molded body is fitted to the inner diameter surface of the second annular region molded body, and the main surface of the fitted body is pressed and integrated, Two types of sheet-like packings 8 on the same plane, in which the first annular region molded body 6 is surrounded and integrated by the second annular region molded body 7 as shown in the schematic sectional view in FIG. I made it. Here, in the first annular region molded body 6, the hollow portion 6a on the inner diameter side functions as a molten metal outflow hole, and the main surface 6b
Forms a sealing surface adjacent to the molten metal outflow hole 6a. further,
In the second annular region molded body 7, the cavity portion 7a on the inner diameter side functions as a fitting / mounting portion for the first annular region molded body 6,
Further, the main surface 7b constitutes the outer circumference of the sealing surface 6b of the first annular region molded body 6.

(Assembly of slide plate device in which immersion nozzles are joined)

According to the configuration shown in FIG. 4, the upper fixed plate 1 facing the molten metal outlet of the molten metal (molten steel) container, the slide plate 2 facing the molten metal outlet hole 1a of the upper fixed plate 1, the above The lower fixing plate 3 facing the molten metal outflow hole 2a of the slide plate 2, the immersion nozzle 4 facing the molten metal outflow hole 3a of the lower fixing plate 3, the immersion nozzle 4 and the lower fixing plate 3
The sheet-like packing 8 was inserted between the above and the above, and the slide plate device which joined the immersion nozzle was produced.

The slide plate device to which the dipping nozzle having the above structure is joined is attached to a ladle having a capacity of 70 tons, and the casting temperature is 1580 to 1600 ° C. and the casting time is 180 to 42.
Continuous casting and testing of molten metal (molten metal) were performed under the condition of 0 minutes. As a result, in all cases, no air was sucked into the dipping nozzle and no hot water leaked. In other words, the occurrence of abnormal damage at the connection between the lower fixed platen 3 and the dipping nozzle 4 or the occurrence of trouble such as molten metal oxidation is reduced (30 to 50% lower than in the conventional case), and the stability is improved. Continuous casting was possible.

The sheet-like packing 8 is formed in the unsintered first annular region 6 in the process of continuous casting and testing.
In the second annular region 7, the low melting point component is softened by the heat of the flowing molten metal, and the refractory material is densified or semi-moltened to contribute to the shield action.

In the above description, an example in which the first annular region 6 and the second annular region 7 constitute the refractory seal member (sheet-like packing) 8 is shown. FIG. 3 shows a schematic sectional view. Thus, for example, between the first annular region 6 and the second annular region 7, the refractory material forming the second annular region 7 has a lower melting point than that of the refractory material forming the first annular region 6. A third annular region 9 made of a refractory material having a higher melting point may be fitted and arranged. Further, in this polycyclic formation, the annular region can be set to 4 or more according to the configuration shown in FIG.

Further, in the above, the structural example of the refractory shield member 8 in which the unsintered first annular region 6 and the second annular region 7 are integrally fitted is described. Even if 6 is a sintered type and the first annular region and the unsintered second annular region 7 are fitted and integrated, the same effect can be obtained.

The present invention is not limited to the above-mentioned embodiment, and the materials, shapes and dimensions of the refractory material to be combined are as follows.
It can be changed and set according to the usage conditions and mode. Of course, it can be used not only for joining a slide gate device joined with an immersion nozzle, but also as a packing member for a joining portion which has a region surface which comes into contact with molten metal and which is required to have a shielding property at high temperature.

[0039]

According to the first to third aspects of the present invention, when used as a slide gate device having an immersion nozzle joined thereto, a stable continuous casting operation becomes possible, and quality, productivity and yield are improved, and Since the cost can be reduced, it contributes to high quality casting and the like due to the operational stability.

[Brief description of drawings]

FIG. 1 is an exploded view of components of a composite seal member according to an embodiment, (a) is a plan view of a first annular region,
FIG. 6B is a plan view of the second annular region.

2 is a cross-sectional view of a composite seal member composed of the components shown in FIG.

FIG. 3 is a cross-sectional view showing the main configuration of a composite seal member according to another embodiment.

FIG. 4 is a vertical cross-sectional view showing the configuration of a main part of a slide gate device in which an immersion nozzle is joined.

[Explanation of symbols]

1 ... Upper fixed plate 1a: Molten metal outflow hole on the upper fixed plate 1b ... first area 1c ... second area 2 …… Slide plate 2a: Molten metal outflow hole of slide plate 3 ... Lower fixed plate 3a: Molten metal outflow hole on the lower fixed plate 4 ... Immersion nozzle 5, 8 ... Sheet packing (seal member) 6 ... First annular region molded body 7 ... Second annular region molded body

Claims (3)

[Claims] 1. A first annular region having a first annular region that contacts molten metal and a second annular region that surrounds and integrates the first annular region in a substantially coplanar manner. The region is made of a corrosion resistant refractory material having a softening temperature of 1400 ° C or higher,
The annular sealing region is made of a refractory material having a softening temperature of 600 to 1100 ° C., the composite seal member for a nozzle joint. 2. A composite seal for a nozzle joint according to claim 1, wherein the planar annular width ratio of the first annular region and the second annular region is 1: 1 to 5: 1. Element. 3. The first annular region and the second annular region contain an organic or resinous binder in an external ratio of 10 to 20% by mass. A composite seal member for a nozzle joint as described.