JP2024007115A - Nozzle shape refractory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress edge cracking while maintaining the flow controllability of molten metal for an extended period of time.

SOLUTION: A nozzle shape refractory has an upper nozzle 10, a slide plate unit 20 including a plurality of mutually slidable plates, and a lower nozzle, in this order, and has an inner hole 40 inside them, where a joint 50 is provided in at least one of a connection between the upper nozzle 10 and the slide plate unit 20, and a connection between the slide plate unit 20 and the lower nozzle, the average thickness of the joints 50 in the inner region 53 that is at least a part of the portion of the joints 50 in contact with the inner hole 40 is greater than the average thickness of the joints 50 in regions other than the inner region 53.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a nozzle-shaped refractory.

BACKGROUND OF THE INVENTION A nozzle-shaped refractory equipped with a slide plate unit is commonly used as an outlet for flowing molten metal from a container such as a ladle or a tundish. In this type of refractory, the flow rate of molten metal is adjusted by adjusting the opening of the flow path by sliding the plates that constitute the slide plate unit. Generally, cylindrical refractories are placed above and below the slide plate unit, and mortar joints filled with refractory mortar are provided in the gaps between the slide plate unit and the adjacent refractories.

In a nozzle-shaped refractory, since high-temperature molten metal flows through the inner hole, a temperature difference occurs between the outer peripheral side and the inner hole side, and cracks may occur in the refractory due to thermal stress. Among these cracks, cracks that originate from the peaks (edges) between the inner hole surface and the sliding surface are called edge cracks, and edge cracks are caused by thermal expansion of the refractory along the flow direction of molten metal. occurs. There is a risk that the area where an edge crack has occurred will be lost as the slide plate unit slides, and further damage may proceed from the missing area, so various studies have been conducted to prevent edge cracks. .

For example, in the plate brick of JP-A-11-245019 (Patent Document 1), by providing a notch at the edge that forms the boundary between the slide plate sliding surface and the inner hole, the This reduces the stress that occurs and suppresses the occurrence of edge cracks. Note that JP-A-11-57989 (Patent Document 2) discloses a plate brick having a recessed edge portion, and the same technical idea as Patent Document 1 can be seen here. Furthermore, in the sliding nozzle plate of JP-A-2-175068 (Patent Document 3), a ring-shaped refractory is arranged in the inner hole, and the base body into which the ring is fitted is made of a material with a higher coefficient of thermal expansion than the ring material. By forming the inner hole, the stress caused by heating the inner hole is alleviated, and the generation of radial cracks from the inner hole toward the outer periphery is suppressed.

Japanese Patent Application Publication No. 11-245019 Japanese Patent Application Publication No. 11-57989 Japanese Unexamined Patent Publication No. 2-175068

However, in the techniques of Patent Document 1 and Patent Document 2, since the joint space necessary for alleviating thermal stress is adjacent to the inner hole, molten steel may enter the space and lead to metal insertion. This is the same situation as when the edge portion of the slide plate is missing due to crack damage, which leads to a decrease in the flow rate controllability of the molten metal, which can cause troubles such as poor molten metal stoppage and steel leakage. Furthermore, the technique disclosed in Patent Document 3 could not be expected to have an effect of suppressing edge cracks.

Therefore, there is a need for a nozzle-shaped refractory that can suppress edge cracks and maintain molten metal flow control over a long period of time.

The nozzle-shaped refractory according to the present invention includes an upper nozzle, a slide plate unit including a plurality of mutually slidable plates, and a lower nozzle in this order, and has an inner hole inside. A joint is provided in at least one of the connecting portion between the upper nozzle and the slide plate unit and the connecting portion between the slide plate unit and the lower nozzle, and a portion of the joint in contact with the inner hole is provided with a joint. The average thickness of the joint in at least a part of the inner region is larger than the average thickness of the joint in a region other than the inner region.

According to this configuration, thermal stress can be alleviated by thickening the joint around the inner hole, thereby suppressing edge cracks. Further, in areas where there is little need to alleviate thermal stress, the joints are made thinner to prevent molten steel and outside air from entering, so the flow rate controllability of molten metal can be maintained for a long period of time.

Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited to the preferred embodiments described below.

In one aspect of the nozzle-shaped refractory according to the present invention, the average thickness of the joints in the inner region is 1.3 times or more and 3.0 times or less the average thickness of the joints in other than the inner region. It is preferable.

According to this configuration, it is easy to achieve both relaxation of thermal stress and gas sealing performance.

In one embodiment of the nozzle-shaped refractory according to the present invention, the radial width of the inner region is 0.1 times or more the diameter of the inner hole, and 0.1 times the radial width of the joint. It is preferable that it is 5 times or less.

According to this configuration, it is easy to achieve both relaxation of thermal stress and gas sealing performance.

In one aspect of the nozzle-shaped refractory according to the present invention, the plates include a first plate that is in contact with the joint, and a second plate that slides on the first plate, and the inner region is It is preferable that the second plate is provided in a portion of the joint that contacts the inner hole in a direction in which the second plate moves relative to the first plate when closing the inner hole.

According to this configuration, since the inner region is provided in a portion where it is especially necessary to alleviate thermal stress, edge cracks can be suppressed more reliably.

In one embodiment, the nozzle-shaped refractory according to the present invention has at least an angle of deviation of -45° or more in a polar coordinate system in which the center of the inner hole in contact with the joint is the origin and the direction of the relative movement is 0°. It is preferable that the inner region is provided in the following regions.

According to this configuration, edge cracks can be further suppressed.

Further features and advantages of the invention will become clearer from the following description of exemplary and non-limiting embodiments, written with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a continuous casting nozzle according to an embodiment. It is a longitudinal cross-sectional view showing the structure of mortar joints of the continuous casting nozzle according to the embodiment. It is a longitudinal cross-sectional view which shows the structure of the mortar joint of the nozzle for continuous casting based on a modification. It is a figure showing arrangement of mortar joints of a nozzle for continuous casting concerning a modification. FIG. 7 is a longitudinal cross-sectional view showing the structure of mortar joints in Examples 2 and 8. FIG. 9 is a longitudinal cross-sectional view showing the structure of mortar joints in Examples 3 and 9. FIG. 7 is a vertical cross-sectional view showing the structure of a mortar joint in Example 4. It is a longitudinal cross-sectional view showing the structure of a mortar joint of a comparative example.

Embodiments of the nozzle-shaped refractory according to the present invention will be described with reference to the drawings. Below, an example in which the nozzle-shaped refractory according to the present invention is applied to a continuous casting nozzle 1 (FIG. 1) for pouring molten steel tapped from a ladle (not shown) into a tundish (not shown) will be explained. .

[Basic configuration of continuous casting nozzle]
The continuous casting nozzle 1 according to the present embodiment includes an upper nozzle 10, a slide plate unit 20, and a lower nozzle 30 in this order from above (FIG. 1). Note that "vertical direction" in this document refers to the vertical direction in FIG. 1 unless otherwise specified. Further, the "horizontal direction" in this document refers to the left-right direction in FIG. 1 unless otherwise specified.

A through hole is provided inside each of the unit members constituting the upper nozzle 10, the slide plate unit 20, and the lower nozzle 30, and these through holes are connected to form an inner hole 40. The slide plate unit 20 includes a fixed plate 21 (an example of a plate) connected to the upper nozzle 10 and a sliding plate 22 (an example of a plate) connected to the lower nozzle 30. include. Mortar joints 50 (51, 52) ( This is an example of a joint).

The continuous casting nozzle 1 is provided below the ladle. Therefore, the molten steel discharged from the ladle moves downward by gravity and is poured into the tundish through the continuous casting nozzle 1 (inner hole 40). Although details will be described later, the continuous casting nozzle 1 includes a slide gate device that can control the flow of molten steel by sliding a slide plate 22 that constitutes a slide plate unit 20. In this embodiment, the sliding plate 22 is connected to the lower nozzle 30, so when opening and closing the slide gate device, the sliding plate 22 and the lower nozzle 30 move together.

The upper nozzle 10, the slide plate unit 20, and the lower nozzle 30 are all made of refractory material. As the refractory used here, dense refractories conventionally used in continuous casting nozzles can be used. As the dense refractory, dense refractories commonly used in this field can be used, and the base material may be alumina, mullite, spinel, magnesia, zirconia, etc., which are commonly used as refractories. Examples of such materials include oxide-based materials and materials that combine these oxides with non-oxides such as carbon.

The mortar joints 50 (51, 52) are made of a mortar material conventionally used in continuous casting equipment. As such a mortar material, for example, thermosetting refractory mortar can be used.

The upper nozzle 10 is a cylindrical body connected to the lower side of the ladle, and a convex portion 11 is provided at the lower end of the upper nozzle 10. Further, the fixed platen 21 has a shape in which a through hole is provided in a part of a plate-like member, and a recessed portion 23 is provided on the upper surface of the fixed platen 21. The upper nozzle 10 and the fixed platen 21 are connected in such a manner that the convex portion 11 and the concave portion 23 fit together. Note that a mortar joint 51 is formed between the convex portion 11 and the concave portion 23.

The lower nozzle 30 is a cylindrical body connected to the lower side of the slide plate unit 20, and a recess 31 is provided at the upper end of the lower nozzle 30. Further, the sliding plate 22 has a shape in which a through hole is provided in a part of a plate-shaped member, and a convex portion 24 is provided on the lower surface of the sliding plate 22. The sliding plate 22 and the lower nozzle 30 are connected in such a manner that the convex portion 24 and the concave portion 31 fit together. Note that a mortar joint 52 is formed between the convex portion 24 and the concave portion 31.

The mortar joint 51 has a shape that follows the shapes of the convex portion 11 and the concave portion 23 (FIG. 2). An inner region 53 is provided in a portion of the mortar joint 51 that is in contact with the inner hole 40 . In this embodiment, an inner region 53 is provided over the entire circumference of the inner hole 40 . For distinction, the area other than the inner area 53 of the mortar joint 51 will be referred to as a normal area 54.

The mortar joint 52 has a shape that follows the shapes of the convex portion 24 and the concave portion 31. Similar to the mortar joint 51, an inner region is provided in a portion that contacts the inner hole 40. Note that the effects brought about by the mortar joints 52 and preferred aspects of the mortar joints 52 are the same as those of the mortar joints 51. However, the dimensional conditions regarding the average thickness and width of the inner region in the mortar joint 52 may be the same as or different from the dimensional conditions regarding the average thickness and width of the inner region in the mortar joint 51. .

The inner region 53 is provided on the inner side (the part in contact with the inner hole 40) where a relatively large thermal stress tends to be a problem, and is designed to prevent thermal expansion of the refractory along the direction in which the inner hole 40 extends (vertical direction in FIG. 1). plays a role in absorbing The refractory mortar constituting the mortar joints 50 (51, 52) has more elasticity than the refractories constituting the upper nozzle 10, slide plate unit 20, and lower nozzle 30. Even if stress is generated that compresses (51, 52) in the vertical direction, the mortar joints 50 (51, 52) can be elastically deformed to alleviate the stress. In order to expect this effect to occur, it is advantageous for the mortar joints 50 (51, 52) to be thicker.

On the other hand, the refractory mortar constituting the mortar joints 50 (51, 52) acts to prevent the entry of molten steel flowing through the inner hole 40 (base metal insertion) and the entry of outside air from the outside of the continuous casting nozzle 1. In terms of this, it is inferior to the refractories that constitute the upper nozzle 10, slide plate unit 20, and lower nozzle 30. Therefore, in order to prevent molten steel and outside air from entering, it is advantageous for the mortar joints 50 (51, 52) to be thin.

In the continuous casting nozzle 1 according to the present embodiment, the mortar joints 50 (51, 52) are locally thickly provided in a portion where thermal stress is likely to be a problem, that is, the inner region 53, and the thermal stress applied from above and below this portion is reduced. I've made it possible for you to relax. On the other hand, in areas where thermal stress is less likely to be a problem, that is, in the normal area 54, thin mortar joints 50 (51, 52) are provided to prevent molten steel and outside air from entering. In this way, by providing the mortar joints 51 with a thickness that corresponds to the function required in each part, edge cracks are suppressed by alleviating thermal stress, and life is extended by preventing intrusion of molten steel and outside air. Both are compatible.

The average thickness of the mortar joints 50 (51, 52) in the inner region 53 is larger than the average thickness of the mortar joints 50 (51, 52) in the normal region 54. More specifically, it is preferable that the average thickness of the mortar joints 50 (51, 52) in the inner region 53 is 1.3 times or more and 3.0 times or less the average thickness of the mortar joints in other regions than the inner region. . When the ratio is 1.3 times or more, the effect of alleviating the thermal stress generated around the inner hole 40 is particularly likely to be exhibited. Further, when the ratio is 3.0 times or less, gas sealing properties of the mortar joints 50 (51, 52) can be easily ensured at a sufficient level. In addition, since the contact area between the molten steel and the mortar material can be suppressed, it is easy to suppress erosion of the joints.

The radial width W1 of the inner region 53 is preferably 0.1 times or more the diameter D of the inner hole 40. When the width W1 is 0.1 times or more the diameter D, the effect of alleviating the thermal stress generated around the inner hole 40 is particularly likely to be exhibited. Note that the radial width W1 of the inner region 53 is defined as the width W1 from the end of the inner region 53 on the inner hole 40 side to the position where the thickness of the mortar joints 50 (51, 52) is the same as the thickness in the normal region 54. , refers to the width of the inner hole 40 along the radial direction.

Further, the radial width W1 of the inner region 53 is preferably 0.5 times or less the radial width W of the entire mortar joint 50 (51, 52). When the width W1 is 0.5 times or less the width W, gas sealing properties of the mortar joints 51 can be easily ensured at a sufficient level. In other words, it is preferable to provide the inner region 53 within half the width of the mortar joints 50 (51, 52).

Note that suitable dimensional conditions regarding the average thickness and width W1 of the inner region 53 include, for example, providing a notch in a portion of the recess 23 corresponding to the inner region 53 so as to satisfy the above conditions. This can be achieved by a method.

[Modified example]
Next, a modified example of the slide plate unit 20 will be shown. In the above embodiment, the inner region 53 is provided over the entire circumference of the inner hole 40, but the inner region may be provided facing only a part of the inner hole. In the slide plate unit 20A according to the modification shown in FIG. 3, an inner region 56 is provided only on the left side of the mortar joint 55 in the figure, and the thickness of the mortar joint 55 is uniform on the right side of the figure. It has become. This modification is realized by the fact that the shape of the fixed platen 25 is different from that of the above embodiment (fixed platen 21), and more specifically, that the shape of the recessed part 26 is different from that of the above embodiment (recessed part 23). Note that the configuration of the sliding plate 22 is the same as in the above embodiment.

Here, with respect to the fixed plate 25 (which is an example of a first plate) with which the mortar joint 55 is in contact, the sliding plate 22 (which is an example of a second plate) that slides thereon is connected to the inner hole. An inner region 56 is provided in a portion on the side in the direction S1 that moves relative to each other when closing 40. FIG. 4 is a schematic diagram showing the positional relationship among the fixed platen 25, the sliding plate 22, and the inner region 56 of the mortar joint 55 in a modified example, viewed from above. The inner region 56 has an angle of deviation θ in a polar coordinate system in which the origin is the center O of the inner hole 40 in contact with the mortar joint 51 and the direction S1 of relative movement of the sliding plate 22 when closing the inner hole 40 is 0°. is provided within a range of ±45°.

When the slide plate 22 is moved in the direction S to partially close the inner hole 40, the lower surface 27 of the fixed plate 25 is exposed to the inner hole 40 in a region centered on the 0° declination in the polar coordinate system ( Figure 3). Therefore, in this region, the fixed platen 25 comes into contact with the molten steel not only on the inner circumferential surface 28 but also on the lower surface 27. Therefore, in this region of the fixed platen 25, the amount of heat received from the molten steel is greater than in other parts, and thermal stress is particularly likely to become a problem. Therefore, it is particularly necessary to provide the inner region 56 in this region.

On the other hand, in other areas, the thermal stress may fall within an allowable range without particularly adjusting the thickness of the mortar joints 55. Therefore, in other areas, priority is given to suppressing outside air suction, and no measures are taken to thicken the mortar joints 55.

For simplicity, the configuration of the sliding plate 22 has been described as being the same as that of the above embodiment, but it is also possible to apply the measure of providing only a partial inner area to the mortar joint between the sliding plate and the lower nozzle. . However, regarding the mortar joint between the sliding plate and the lower nozzle, the direction S2 (Fig. 3) of relative movement of the fixed plate when closing the inner hole should be treated as 0° in the polar coordinate system, and therefore the inside It should be noted that locations where it is highly necessary to provide areas appear horizontally reversed from the mortar joints 55 of the above modification.

For both the mortar joint between the upper nozzle and the slide plate unit and the mortar joint between the slide plate unit and the lower nozzle, as in the above modification, the first plate with which the mortar joint is in contact On the other hand, it is preferable that an inner region is provided on the side in which the second plate sliding therewith moves relative to the second plate when closing the inner hole. Further, it is more preferable that the inner region is provided at least in a region where the declination angle in a polar coordinate system where the direction of relative movement is 0° is −45° or more and 45° or less.

[Other embodiments]
Finally, other embodiments of the nozzle-shaped refractory according to the present invention will be described. Note that the configurations disclosed in each of the embodiments below can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs.

In the above embodiment, the slide plate unit 20 has been described as an example of a configuration in which the fixed plate 21 and the sliding plate 22 are combined. However, in the nozzle-shaped refractory according to the present invention, the number of plates constituting the slide plate unit may be any number greater than or equal to two. For example, the present invention can be implemented as a nozzle-shaped refractory that includes a slide plate unit having three plates, a fixed plate, a seal plate, and a sliding plate, in order from the top.

In the above-described embodiment, the mortar joint 51 between the upper nozzle 10 and the fixed plate 21 and the mortar joint 52 between the sliding plate 22 and the lower nozzle 30 are both provided with inner regions. It was explained as follows. However, in the nozzle-shaped refractory according to the present invention, a joint having an inner area is provided in at least one of the connection portion between the upper nozzle and the slide plate unit and the connection portion between the slide plate unit and the lower nozzle. It suffices to have one on both sides, and it is not necessarily necessary to provide one on both sides.

In the embodiment described above, the configuration in which a notch is provided in a part of the recess 23 to form the inner region 53 has been described as an example. However, in the nozzle-shaped refractory according to the present invention, the method for forming the inner region is not limited to the above example, and the inner region is formed in one or both of the upper nozzle and the slide plate unit (or the slide plate unit and the lower nozzle) in contact with the joint. , just provide a notch.

In the above embodiment, the thickness of the mortar joints 51 in the inner region 53 is uniform. However, the thickness of the joint may not be uniform within the inner region. Note that even within the normal region, the thickness of the joint may or may not be uniform.

The joints in the present invention are not limited to mortar joints, but may be joints made of materials commonly used as joint materials in the art. Examples of such materials include refractory ceramic fibers. Even if mortar joints are used, the construction method is not limited; mortar may be applied to the connection between the nozzle and slide plate unit when assembling the nozzle-shaped refractories, or packing-shaped joints may be applied in advance. A shaped mortar may be placed at the connection.

In the above embodiment, the convex part 11 of the upper nozzle 10 and the concave part 23 of the fixed platen 21 are fitted together, and the concave part 31 of the lower nozzle 30 and the convex part 24 of the sliding plate 22 are fitted. Explained as an example. However, in the nozzle-shaped refractory according to the present invention, the shape of the connecting portion between the upper nozzle or the lower nozzle and the slide plate unit is not particularly limited. For example, a fitting shape in which the nozzle is convex and the slide plate unit is concave (an example is the fitting between the convex part 11 of the upper nozzle 10 and the concave part 23 of the fixed platen 21), and a slide plate unit in which the nozzle is concave. The fitting shape is convex (an example is the fitting between the concave part 31 of the lower nozzle 30 and the convex part 24 of the sliding plate 22), a structure in which both the nozzle and the slide plate unit are flat, etc. Illustrated.

Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects, and the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, other embodiments that are modified without departing from the spirit of the present invention are naturally included within the scope of the present invention.

In the following, the present invention will be further explained by showing examples. However, the following examples do not limit the present invention.

[Nozzle-shaped refractory]
In each of the examples and comparative examples, nozzle-shaped refractories having shapes shown in FIG. 1 were created. However, in each example, the diameter of the inner hole was 90 mm, and the shape of the mortar joint between the upper nozzle and the slide plate unit was changed in each example. The shape of the mortar joints in each example will be described later. Note that the conditions of the refractories constituting the upper nozzle, slide plate unit, and lower nozzle, and the mortar material constituting the mortar joints are the same as in the embodiment described above. Furthermore, the mortar joint between the slide plate unit and the lower nozzle had a constant thickness in all examples.

〔Evaluation methods〕
The nozzle-shaped refractories of Examples and Comparative Examples were each used as a slide valve device attached to the lower part of a ladle. For each example, the ladle was used multiple times, counting the use until all the molten steel was discharged as one time, and the number of uses was counted until damage was observed and the ladle was judged to be unusable.

[Shape of each example]
(Example 1)
The shape of the mortar joint was the shape shown in FIG. 2 (mortar joint 51). In this example, the average thickness of the mortar joints in the inner region was 4.0 mm, and the average thickness of the mortar joints in the normal region was 2.0 mm. That is, the average thickness of mortar joints in the inner region was 2.0 times the average thickness of mortar joints in the normal region. In this example, the thickness of the mortar joints was uniform (4.0 mm) throughout the inner region. Further, the radial width of the inner region was 15 mm, and the radial width of the entire mortar joint was 50 mm. That is, the radial width of the inner region was 0.17 times the diameter of the inner hole and 0.30 times the radial width of the entire mortar joint.

(Example 2)
The shape of the mortar joint was set as shown in FIG. 5 (mortar joint 51A). The second embodiment differs from the first embodiment in that notches are provided in both the upper nozzle and the slide plate unit. In this example, the average thickness of the mortar joints in the inner region was 5.0 mm, and the average thickness of the mortar joints in the normal region was 2.0 mm. That is, the average thickness of mortar joints in the inner region was 2.5 times the average thickness of mortar joints in the normal region. In this example, the thickness of the mortar joints was uniform (5.0 mm) throughout the inner region. Further, the radial width of the inner region was 15 mm, and the radial width of the entire mortar joint was 50 mm. That is, the radial width of the inner region was 0.17 times the diameter of the inner hole and 0.30 times the radial width of the entire mortar joint.

(Example 3)
The shape of the mortar joint was set to the shape shown in FIG. 6 (mortar joint 51B). The third embodiment differs from the first embodiment in that the slide plate unit is provided with two-stage notches. In this example, the average thickness of the mortar joints in the inner region was 4.8 mm, and the average thickness of the mortar joints in the normal region was 2.0 mm. That is, the average thickness of mortar joints in the inner region was 2.4 times the average thickness of mortar joints in the normal region. Further, the radial width of the inner region was 20 mm, and the radial width of the entire mortar joint was 50 mm. That is, the radial width of the inner region was 0.22 times the diameter of the inner hole and 0.40 times the radial width of the entire mortar joint. Note that in this example, the inner area is divided into two areas. The area directly in contact with the inner hole has a radial width of 10 mm and a mortar joint thickness of 6.0 mm. The region following this has a radial width of 10 mm and a mortar joint thickness of 3.5 mm.

(Example 4)
The shape of the mortar joint was set as shown in FIG. 7 (mortar joint 51C). The fourth embodiment differs from the first embodiment in that the slide plate unit is provided with an inclined notch. In this example, the average thickness of the mortar joints in the inner region was 3.5 mm, and the average thickness of the mortar joints in the normal region was 2.0 mm. That is, the average thickness of mortar joints in the inner region was 1.8 times the average thickness of mortar joints in the normal region. Further, the radial width of the inner region was 20 mm, and the radial width of the entire mortar joint was 50 mm. That is, the radial width of the inner region was 0.22 times the diameter of the inner hole and 0.40 times the radial width of the entire mortar joint. In this example, the thickness of the mortar joint in the inner region gradually decreases from the part directly in contact with the inner hole toward the outside, and is 5.0 mm in the part directly in contact with the inner hole. , 2.0 mm at the outer edge of the inner region.

(Example 5)
The shape of the mortar joint was set as shown in FIGS. 3 and 4 (mortar joint 55). However, θ was set to 60°. In this example, the average thickness of the mortar joints in the inner region was 4.0 mm, and the average thickness of the mortar joints in the normal region was 2.0 mm. That is, the average thickness of mortar joints in the inner region was 2.0 times the average thickness of mortar joints in the normal region. In this example, the thickness of the mortar joints was made uniform (4.0 mm) throughout the inner region. Further, the radial width of the inner region was 15 mm, and the radial width of the entire mortar joint was 50 mm. That is, the radial width of the inner region was 0.17 times the diameter of the inner hole and 0.30 times the radial width of the entire mortar joint.

(Example 6)
The procedure was the same as in Example 5 except that θ was set to 45°.

(Example 7)
The procedure was the same as in Example 1 except that the radial width of the inner region was 5.0 mm. In this example, the radial width of the inner region was 0.056 times the diameter of the bore and 0.10 times the radial width of the entire mortar joint.

(Example 8)
The procedure was the same as in Example 1 except that the radial width of the inner region was 28 mm. In this example, the radial width of the inner region was 0.31 times the diameter of the bore and 0.56 times the radial width of the entire mortar joint.

(Example 9)
The procedure was the same as in Example 1 except that the thickness of the mortar joint in the inner region was 2.5 mm. In this example, the average thickness of mortar joints in the inner region was 1.3 times the average thickness of mortar joints in the normal region.

(Example 10)
The procedure was the same as in Example 5 except that θ was set to 30°.

(Comparative example)
The shape of the mortar joint was set as shown in FIG. 8 (mortar joint 51D). In this example, no inner region was provided at the mortar joint, and the thickness of the mortar joint was uniformly 2.0 mm.

〔Evaluation results〕
Table 1 shows the dimensional conditions for each example and comparative example and the number of times each example was used. In addition, for comparison with Example 5 (θ = 60°), Example 6 (θ = 45°), and Comparative Example 5 (θ = 30°), the other examples are shown in Table 1 with θ set to 180°. It shows.

Table 1: Examples and comparative examples

As shown in Table 1, in all Examples, the number of times of use increased compared to the Comparative Example. In addition, in Examples 1 to 6 and 8, the increase in the number of times of use was particularly remarkable. However, in Example 8, a slight deterioration in the quality of the steel was observed compared to Examples 1 to 6. This is considered to be because the amount of outside air sucked in Example 8 was larger than in Examples 1 to 6.

INDUSTRIAL APPLICATION This invention can be utilized as a nozzle used for continuous casting or ingot making, for example.

1: Continuous casting nozzle 10: Upper nozzle 11: Convex portion 20: Slide plate unit 21: Fixed plate 22: Sliding plate 23: Concave portion 24: Convex portion 30: Lower nozzle 31: Concave portion 40: Inner hole 50: Mortar joint 51: Mortar joint 52: Mortar joint 53: Inside area 54: Normal area 20A: Slide plate unit (modified example)
25: Fixed plate (modified example)
26: Recess (modified example)
27: Bottom surface (modified example)
28: Inner peripheral surface (modified example)
55: Mortar joint (modified example)
56: Inner area (modified example)
S: Direction of relative movement of the sliding plate to the fixed plate S2: Direction of relative movement of the fixed plate to the sliding plate O: Center of the inner hole θ: Declination angle

Claims (5)

An upper nozzle, a slide plate unit including a plurality of mutually slidable plates, and a lower nozzle are provided in this order, and the nozzle-shaped refractory has an inner hole inside,
A joint is provided in at least one of the connection portion between the upper nozzle and the slide plate unit and the connection portion between the slide plate unit and the lower nozzle,
A nozzle-shaped refractory, wherein an average thickness of the joint in an inner region that is at least a part of a portion of the joint in contact with the inner hole is larger than an average thickness of the joint in a region other than the inner region. The nozzle-shaped refractory according to claim 1, wherein the average thickness of the joints in the inner region is 1.3 times or more and 3.0 times or less the average thickness of the joints outside the inner region. The nozzle according to claim 1 or 2, wherein the radial width of the inner region is 0.1 times or more the diameter of the inner hole and 0.5 times or less the radial width of the joint. shaped refractories. The plates include a first plate that is in contact with the joint, and a second plate that slides on the first plate,
The inner region is provided in a portion of the joint in contact with the inner hole on a side in a direction in which the second plate moves relative to the first plate when closing the inner hole. The nozzle-shaped refractory according to claim 1 or 2. At least, the inner region is provided in an area where the deviation angle in a polar coordinate system whose origin is the center of the inner hole with which the joint contacts and the direction of the relative movement is 0° is from −45° to 45°. The nozzle-shaped refractory according to item 4.

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