Immersion nozzle for continuous casting

Abstract

The present invention provides a continuous casting nozzle that prevents mortar peeling in high-temperature environments and prevents displacement of the nozzle body or metal case. [Solution] In a continuous casting nozzle, particularly a quick-change type immersion nozzle 10, the neck portion 10a, the joint portion 10c, and the sliding plate 12 are covered by a metal case 11. The metal case is fixed to the nozzle body by mortar filled in the gap 15 between the nozzle body and the metal case. Here, the immersion nozzle has a locking portion 20 with a recess 21 at a predetermined position on the peripheral wall surface of the neck portion, which is recessed along the radial direction when viewed in a vertical cross-section. The mortar filled to the back of the recess 21 hardens and locks into the locking portion. This increases the contact area of ​​the mortar with the neck portion and improves the degree of adhesion, so that the nozzle body or metal case does not shift from its predetermined position in high-temperature environments such as preheating.

Description

Technical Field

[0001] The present invention relates to a nozzle for continuous casting. immersion

Background Art

[0002] A nozzle for continuous casting is a refractory for pouring molten steel into another molten steel holding container such as a tundish or a mold below, which is joined to a molten steel outlet of a single molten steel holding container located above such as a ladle or a tundish. Therefore, the nozzle body of the nozzle for continuous casting may be covered with a metal case from the viewpoint of preventing breakage during movement and replacement. The metal case is composed of a predetermined refractory powder and clay, and is fixed to the nozzle body using a mortar having plasticity as an adhesive.

[0003] The nozzle for continuous casting disclosed in Japanese Patent Laid-Open No. 2-217144 takes a long nozzle as an example. When fixing the metal case to the nozzle body, protrusions are provided on the nozzle body to equalize the thickness of the mortar and facilitate the positioning of the metal case, thereby improving the fitting accuracy of the metal case.

[0004] Among such nozzles for continuous casting, a submerged nozzle used in an injection step for performing a process of injecting molten steel into a mold disposed below, which is joined to the molten steel outlet of a tundish, is frequently replaced at least once or several times for each such injection step. A submerged nozzle developed to smoothly and quickly perform this frequently performed nozzle replacement operation and not cool the molten steel and the next preheated nozzle is called a quick change type. A quick change type submerged nozzle has a flat sliding plate joined to the nozzle neck that fits into a sliding guide installed near the molten steel outlet of the tundish. ​The aforementioned metal case covers at least the sliding plate and nozzle neck, protecting them from impact during replacement. Then, a nozzle changer and a preheating device are installed near the tundish. The nozzle changer is configured to push a sliding plate from the unused immersion nozzle side, relative to the immersion nozzles in use and unused immersion nozzles, which are lined up along a sliding guide. This pushes out the immersion nozzle in use, allowing for quick replacement with an unused one. The preheating device is configured to heat the immersion nozzle, including the metal case that covers the neck of the nozzle body and the sliding plate, in order to preheat the next immersion nozzle to a predetermined temperature. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2-217144 [Overview of the project] [Problems that the invention aims to solve]

[0006] The continuous casting nozzles described above are used in high-temperature environments, with molten steel at high temperatures flowing through the nozzle bore. In particular, immersion nozzles, among the continuous casting nozzles, are preheated to a predetermined temperature before use to prevent damage from thermal shock caused by the high-temperature molten steel flowing through the nozzle bore. When the nozzle body, mortar, and metal case are heated in such a high-temperature environment, all three will expand due to the heat. In this case, the expansion rate of the mortar may be greater than that of the nozzle body or metal case. Here, the continuous casting nozzle, which consists of a roughly cylindrical nozzle body and a metal case covering it, is connected to the molten steel outlet of one molten metal holding container located above, and is used in an upright position along the axial direction to pour molten steel into another molten metal holding container located below. During use, that is, while high-temperature molten steel is flowing through the nozzle bore or during preheating, the nozzle undergoes significant thermal expansion. If the flow of molten steel is interrupted, or if preheating is complete and the nozzle is in standby mode, the continuous casting nozzle cools down through natural heat dissipation, causing the expanded mortar to cool and contract. If the mortar, which has expanded significantly compared to the nozzle body or metal case, shrinks to a thickness less than its original thickness, it may detach from the nozzle body or metal case, creating a gap in the detached area. When mortar like this peels off the nozzle body or metal case, and the continuous casting nozzle is used upright, there is a problem that the nozzle body or metal case may sag or fall off from its designated position due to its own weight along with the weight of the mortar.

[0007] The misalignment of the nozzle body or metal case described above is a problem that can occur in all continuous casting nozzles equipped with a metal case and used in high-temperature environments. However, in recent years, this problem can be even more pronounced in quick-change type immersion nozzles, which are now preheated to particularly high temperatures. This is likely because quick-change type immersion nozzles have a large, flat sliding plate that protrudes significantly from the upper end of the neck of the nozzle body. The weight of the metal case covering the sliding plate, which overhangs from the neck of the nozzle body, places a significant load on the mortar below. Furthermore, if the metal case shifts from its designated position on the sliding plate or becomes detached and twisted during preheating, it may become impossible to set the immersion nozzle in the nozzle changer. This could alter the timing and cycle of replacing the immersion nozzle, potentially preventing continuous casting from proceeding as planned.

[0008] Here, in the invention related to a continuous casting nozzle disclosed in the above-mentioned Japanese Patent Publication No. 2-217144, which provides projections on the nozzle body to improve the positioning accuracy of the metal case, the detailed description of the invention exemplifies a long nozzle, so it is not clear whether a structure with simple projections at key points on the nozzle body can prevent mortar peeling and fix the metal case that protrudes significantly together with the sliding plate. However, the inventors of the present invention have conceived that by making appropriate improvements based on the prior invention related to the continuous casting nozzle, it may be possible to enhance the effect of preventing the metal case covering the sliding plate from shifting.

[0009] Therefore, the problem that the present invention aims to solve is to prevent mortar peeling in a high-temperature environment and to prevent displacement of the nozzle body or metal case for continuous casting. immersion The objective is to provide a nozzle. [Means for solving the problem]

[0010] Continuous casting method according to claim 1 immersion The nozzle is A joint comprising a roughly flat sliding plate, It consists of a neck that is roughly the shape of an inverted truncated cone and a roughly cylindrical body that is integrally formed and connected to the lower end of the neck. The lower surface of the joint is integrally connected to the upper end surface of the neck portion. The nozzle body and the nozzle body The aforementioned joint and It consists of a metal case that covers the aforementioned neck portion, A continuous casting method is used, wherein a predetermined refractory material with plasticity is filled into the gap formed between the nozzle body and the metal case, thereby fixing the metal case to the nozzle body. immersion It is a nozzle, At a predetermined position on the peripheral wall surface of the neck portion, when the peripheral wall surface is viewed in a longitudinal section along the axial direction, it is recessed along the radial direction. Along with, grooves formed along the circumferential direction of the peripheral wall surface, or When the peripheral wall surface is viewed in a longitudinal section along the axial direction, Projecting radially Along with the circumferential ridges formed along the circumferential direction of the aforementioned peripheral wall surface A locking portion is provided, formed from either one or both of the following: The invention is characterized in that the refractory material is locked to the locking portion.

[0011] The nozzle for continuous casting according to claim 2 immersion In the invention according to claim 1, when the nozzle body is viewed in a longitudinal sectional view along the axial direction, the concave groove and the Projection are formed so as to be adjacent to each other alternately.

[0012] The nozzle for continuous casting according to claim 3 immersion In the invention according to claim 1, the refractory is mortar.

Advantages of the Invention

[0013] According to the present invention In the immersion nozzle for continuous casting thus, The continuous casting immersion nozzle consists of a joint with a substantially flat sliding plate, a neck portion that is substantially inverted truncated cone shape, and a substantially cylindrical body portion integrally formed to the lower end of the neck portion, with the lower surface of the joint integrally formed to the upper end surface of the neck portion, and a metal case that covers the joint and neck portion of the nozzle body. The gap formed between the nozzle body and the metal case is filled with a predetermined refractory material that has plasticity, thereby fixing the metal case to the nozzle body. At this time, A locking portion is provided at a predetermined position on the circumferential wall surface of the neck, formed from either a groove that is recessed radially and formed along the circumferential direction of the circumferential wall surface when the circumferential wall surface is viewed in a longitudinal section along the axial direction, or a projection that is radially protruding and formed along the circumferential direction of the circumferential wall surface when the circumferential wall surface is viewed in a longitudinal section along the axial direction, or both thereof, so that refractory material can be locked into the locking portion. Thereby, the contact area of the refractory with respect to the neck portion can be increased, and the adhesion degree of the refractory with respect to the neck portion can be improved. And groove is filled with the refractory, or Projection bites into the refractory to fix the refractory to the locking portion. Therefore, even in a high-temperature environment such as preheating, when the refractory peels off from the nozzle body or the refractory is slightly damaged and the weight of the refractory is added to the metal case, the refractory locked to the locking portion can hold the nozzle body or the metal case in a predetermined position. In this way, the adhesion degree of the refractory with respect to the neck portion of the nozzle body is improved, and the refractory locked to the locking portion holds the metal case. Therefore, it is possible to prevent the nozzle body or the metal case from deviating from a predetermined position in a high-temperature environment such as preheating. Furthermore, by configuring the nozzle as a groove or protrusion along the circumferential direction, it is possible to prevent the manufacturing process from becoming complicated and reduce manufacturing costs. And preferably, when the nozzle body is viewed in a longitudinal sectional view along the axial direction, groove and Projection are formed adjacent to each other alternately. Thereby, the contact area of the refractory with respect to the neck portion of the nozzle body is increased to improve the adhesion degree, and groove and ProjectionThe refractory material, which is secured to the locking portion composed of the above, holds the metal case in place, thus preventing the metal case from shifting from its predetermined position in high-temperature environments such as preheating. More preferably, mortar was used as the refractory material. This improves the workability when fixing the metal case to the nozzle body. [Brief explanation of the drawing]

[0014] [Figure 1] This is an explanatory diagram showing a schematic configuration of a continuous casting immersion nozzle according to the first embodiment. [Figure 2] This is a partially enlarged cross-sectional view showing a schematic representation of the longitudinal cross-sectional shape along the axial direction around the neck portion of the immersion nozzle for continuous casting according to the first embodiment. [Figure 3] This is a partially enlarged cross-sectional view showing variations in the shape of the locking portion of the immersion nozzle for continuous casting according to the first embodiment, when viewed in a longitudinal section. [Figure 4] This is an explanatory diagram showing a schematic configuration of the neck area of ​​the immersion nozzle for continuous casting according to the first embodiment. [Figure 5] This is an explanatory diagram illustrating the schematic configuration of other components around the neck of the immersion nozzle for continuous casting according to the first embodiment. [Figure 6] This is an explanatory diagram illustrating the general configuration of other configuration examples for the neck area of ​​the immersion nozzle for continuous casting according to the first embodiment. [Figure 7] This diagram illustrates the state of the immersion nozzle after heating when it is heated, as described in the first embodiment of the heating test of the immersion nozzle for continuous casting. [Figure 8] This is an explanatory diagram showing the state after heating when a conventional immersion nozzle is heated, as described in the heating test of the immersion nozzle for continuous casting according to the first embodiment. [Figure 9] This is a partially enlarged cross-sectional view showing a schematic representation of the longitudinal cross-sectional shape along the axial direction around the neck portion of the immersion nozzle for continuous casting according to the second embodiment. [Figure 10]This is a partially enlarged cross-sectional view showing variations in the shape of the locking portion of the immersion nozzle for continuous casting according to the second embodiment, when viewed in a longitudinal section. [Figure 11] This is an explanatory diagram illustrating the schematic configuration of the neck area of ​​the immersion nozzle for continuous casting according to the second embodiment. [Figure 12] This is an explanatory diagram illustrating the schematic configuration of other components around the neck of the immersion nozzle for continuous casting according to the second embodiment. [Figure 13] This is an explanatory diagram illustrating the general configuration of other examples of the neck area of ​​the immersion nozzle for continuous casting according to the second embodiment. [Figure 14] This is a partially enlarged cross-sectional view showing a schematic representation of the longitudinal cross-sectional shape along the axial direction around the neck portion of the immersion nozzle for continuous casting according to the third embodiment. [Figure 15] This is a partially enlarged cross-sectional view showing variations in the shape of the locking portion of the immersion nozzle for continuous casting according to the third embodiment, when viewed in a longitudinal section. [Figure 16] This is an explanatory diagram illustrating the schematic configuration of the neck area of ​​the immersion nozzle for continuous casting according to the third embodiment. [Figure 17] This is an explanatory diagram illustrating the schematic configuration of other components around the neck of the immersion nozzle for continuous casting according to the third embodiment. [Modes for carrying out the invention]

[0015] This invention can be highly effective for all types of nozzles used in continuous casting, and is particularly effective for immersion nozzles, which are known as quick-change type nozzles. As shown in Figures 1 and 2, the quick-change type continuous casting immersion nozzle 10 consists of a nozzle body and a metal case 11. The nozzle body consists of a neck portion 10a with a roughly inverted truncated cone shape, a cylindrical body portion 10b connected to the lower end of the neck portion 10a, and a joint portion 10c having a roughly flat sliding plate 12 connected to the upper end of the neck portion 10a. The specific shapes of the neck portion 10a, the body portion 10b, and the sliding plate 12 are designed as appropriate. As shown in the figure, the metal case 11 consists of a box-shaped portion 11a that covers the joint portion 10c, and a portion connected to the box-shaped portion 11a that surrounds the neck portion 10a. canopy It consists of a cylindrical body portion 11b. The outer wall or lower end surface of the box portion 11a is configured to slide along a guide rail (not shown) that guides the nozzle body to a predetermined position opposite the molten steel outlet of the tundish (not shown). This allows the outer wall and lower end surface of the box portion 11a to slide along the guide rail, enabling quick replacement from one immersion nozzle to another, and the metal case 11 protects the nozzle body from the impact that occurs during such replacement. As shown in Figure 2, the gap 15 formed between the neck portion 10a and the metal case 11 is filled with refractory material. Preferably, this refractory material is mortar, which is made by mixing a predetermined powdered refractory material and clay in a predetermined ratio and kneading it with water or a predetermined organic resin. As the filled mortar hardens, the metal case 11 can be fixed to the nozzle body via the mortar. The following describes various embodiments of the present invention using a nozzle in which a metal case 11 is assembled with mortar to an immersion nozzle 10 as shown in Figure 1 as an example. [Examples]

[0016] For continuous casting according to the present invention immersion An example of the nozzle will be described with reference to the attached drawings. Figure 1 is an explanatory diagram illustrating a continuous casting immersion nozzle as described above. Figure 2 is a partially enlarged cross-sectional view showing a portion of the joint and neck of the continuous casting immersion nozzle when viewed in a longitudinal section along the axial direction of the nozzle body.

[0017] For continuous casting shown in Figure 1 immersion nozzle 10 As described above, it consists of the nozzle body and the metal case 11. The nozzle body consists of a neck portion 10a that is roughly in the shape of an inverted truncated cone, a cylindrical body portion 10b that is connected to the lower end of the neck portion 10a, and a joint portion 10c that is connected to the upper end of the neck portion 10a. As shown in the figure, the metal case 11 consists of a box-shaped portion 11a that covers the joint portion 10c, and a portion connected to the box-shaped portion 11a that surrounds the neck portion 10a. canopy It consists of a cylindrical body portion 11b. The outer wall or lower end surface of the box portion 11a is configured to slide along a guide rail (not shown) that guides the nozzle body to a predetermined position opposite the molten steel outlet of the tundish (not shown). This allows the outer wall and lower end surface of the box portion 11a to slide along the guide rail, enabling quick replacement from one immersion nozzle to another, and the metal case 11 protects the nozzle body from the impact that occurs during such replacement. As shown in Figure 2, the gap 15 formed between the neck portion 10a and the metal case 11 is filled with refractory material. Preferably, the refractory material is mortar, which is made by mixing a predetermined powdered refractory material and clay in a predetermined ratio and kneading it with water or a predetermined organic resin. As the filled mortar hardens, the metal case 11 can be fixed to the neck portion 10a and joint portion 11c of the nozzle body via the mortar.

[0018] The joint portion 10c is equipped with a substantially flat sliding plate 12, and a nozzle inner hole 13a is formed in the approximate center of the sliding plate 12, penetrating toward the neck portion 10a. The upper surface of the sliding plate 12 is configured to abut against a predetermined refractory material installed around the molten steel outlet of the tundish, and to be slidable.

[0019] As shown in Figure 1, the neck portion 10a, which is roughly inverted truncated cone shape, has a diameter at the upper end that is slightly larger than the diameter at the lower end, and is formed to protrude outward as it approaches the upper joint portion 10c. The nozzle bore 13b of the neck portion 10a communicates with the nozzle bore 13a of the joint portion 10c and penetrates through to the body portion 10b along its axis. A locking portion 20 is provided at a predetermined position on the outer peripheral wall surface of the neck portion 10a. The cylindrical body portion 10b is connected to the neck portion 10a at its upper end and has a pair of discharge ports 14 near its lower end. The nozzle inner hole 13c of the body portion is axially connected from the nozzle inner hole 13b of the neck portion toward the discharge ports 14. When the immersion nozzle 10 described above is installed in a predetermined position directly facing the molten steel outlet of the tundish, the nozzle's internal holes 13a, 13b, and 13c communicate with each other from the molten steel outlet toward the discharge port 14, allowing molten steel to be supplied into the mold (not shown).

[0020] Here, Figure 2 is a partially enlarged cross-sectional view showing the portion relating to the gap 15 between the neck portion 10a and the metal case 11, when viewed in a longitudinal section along the axial direction of the nozzle body. As shown in Figure 2, the locking portion 20 provided on the neck portion 10a is composed of a recess 21 cut out to a predetermined depth along the radial direction of the neck portion 10a. Furthermore, the longitudinal cross-sectional shape of the recess 21 is not limited to the rectangular cross-section shown in Figure 2. That is, the longitudinal cross-sectional shape of the recess may be, for example, a semicircular recess 21a shown in Figure 3(a), a trapezoidal recess 21b shown in Figure 3(b), or a triangular recess 21c shown in Figure 3(c).

[0021] Furthermore, the recess 21, which has the above-described vertical cross-sectional shape as the locking portion 20, forms a groove 22 that is formed to encircle the outer peripheral wall surface in a strip-like manner, as shown in Figure 4. In this embodiment, the locking portion 20 is a groove 22 for ease of processing, but it is not limited to this. For example, as shown in Figure 5, the locking portion 20 may be a plurality of elongated slits 23 arranged at predetermined intervals along the circumferential direction on the outer peripheral wall surface of the neck portion 10a, or, as shown in Figure 6, a closed-end hole portion 24 with an open end formed in a predetermined shape may be provided on the outer peripheral wall surface of the neck portion 10a. These can achieve the same effect as the recess 21 described above. The predetermined shape of the open end of the closed-end hole portion 24 may be, for example, a circular open end 24a shown in Figure 6(a), a triangular open end 24b shown in Figure 6(b), or a rhomboid or rectangular open end 24c shown in Figure 6(c). In this way, by providing the locking portion 20 at a predetermined position on the outer peripheral wall surface of the neck portion 10a, the mortar can be filled into the groove 22, slit 23, or bottomed hole 24 of the locking portion 20 and solidified. Therefore, the contact area of ​​the mortar with the neck portion 10a can be increased, improving the degree of adhesion of the mortar to the outer peripheral wall surface, and thus the mortar can be bonded to the neck portion 10a very strongly.

[0022] A heating test was conducted by placing the immersion nozzle 10 having the above configuration in an environment similar to actual usage conditions and preheating treatment. Figure 7 shows an explanatory diagram of the immersion nozzle 10 equipped with the locking part 20 according to this embodiment after heating, and Figure 8 shows an explanatory diagram of a conventional immersion nozzle after heating for comparison.

[0023] As shown in Figures 7 and 8, the heating test involved heating the immersion nozzle according to this embodiment and a conventional immersion nozzle in a high-temperature environment of 1100°C for 2 hours. In the conventional immersion nozzle shown in Figure 8, a gap is created between the lower surface of the joint 10c and the upper surface of the mortar, causing the metal case 11 to shift downward from its predetermined position before heating. On the other hand, in the immersion nozzle according to this embodiment shown in Figure 7, no gap is created between the lower surface of the joint 10c and the upper surface of the mortar. Considering the occurrence of gaps and the downward displacement of the metal case 11 in the case of conventional immersion nozzles, it is thought that the cause is the significant thermal expansion of the mortar filled between the peripheral wall surface of the neck portion 10a and the inner wall surface of the metal case 11 when heated. In other words, when heated, the mortar expands significantly, greatly widening the gap 15 between the peripheral wall surface of the neck portion 10a and the inner wall surface of the metal case 11. After the heating test is completed, as it cools and contracts, in the so-called overhang portion that protrudes significantly from the outer peripheral wall surface on the lower side of the joint portion 10c, the weight of the mortar itself and the metal case 11 to which the mortar is adhered is added during such contraction, causing the adhesion on the joint portion 10c side to peel off, and the mortar to sink together with the metal case 11. Furthermore, in heating tests other than those shown in Figure 8, it was confirmed that the higher the heating temperature, the greater the amount of displacement of the metal case 11 relative to the nozzle body. From the above, it is thought that the thermal expansion of the mortar has a significant effect on the formation of the gap between the metal case 11 and the joint portion 10c, and on the downward displacement of the metal case 11 relative to the nozzle body. In contrast, in the immersion nozzle 10 according to this embodiment, even if the mortar filled between the peripheral wall surface of the neck portion 10a and the inner wall surface of the metal case 11 undergoes significant thermal expansion during heating, the filled mortar expands in a way that widens the gap between the peripheral wall surface of the neck portion 10a and the inner wall surface of the metal case 11, thus expanding toward the recess 21 related to the filled locking portion 20. Furthermore, since the contact area of ​​the mortar with the neck portion 10a is increased and the degree of adhesion is improved, the mortar does not peel off from the peripheral wall surface of the neck portion 10a before and after the heating test. Therefore, even if the mortar shrinks as it cools, it does not fall out of the recess 21, and it is considered that no displacement of the metal case 11 relative to the neck portion 10a occurs. Furthermore, since the immersion nozzle 10 is heated in an upright position during preheating, when the mortar that has expanded due to heat contracts due to cooling, the mortar filled horizontally, such as on the lower surface of the joint 10c, falls and peels off due to its own weight, pulling on the mortar filled vertically. In this case, it is not limited to providing the locking portion 20 on the neck portion 10a of the nozzle body, as in the immersion nozzle 10 of this embodiment, but the same locking portion 20 may also be provided on the side of the joint 10c facing the inner surface of the box portion 11a of the metal case 11. Even in this case, displacement of the metal case 11 can be prevented.

[0024] Therefore, with the continuous casting nozzle according to this embodiment, particularly the quick-change type immersion nozzle 10, even after preheating, it is possible to prevent the metal case 11 from sliding down due to mortar peeling off due to thermal expansion, as shown in Figure 7. As a result, the quick-change type immersion nozzle can be quickly set on the guide rail after preheating, and can be quickly replaced along the guide rail from the immersion nozzle currently in use to the next immersion nozzle to be used. Furthermore, even with continuous casting nozzles other than the immersion nozzle 10, for example, if the nozzle body is housed in a metal case and the metal case is fixed to the nozzle body with mortar, providing the same locking part 20 as described above will prevent the mortar from peeling off and the metal case 11 from falling off when exposed to the high-temperature environment during preheating or continuous casting. [Examples]

[0025] Next, another embodiment of the immersion nozzle for continuous casting will be described with reference to the attached drawings. Figure 9 is a partially enlarged cross-sectional view showing the portion relating to the gap between the neck and the metal case when the nozzle body is viewed in a longitudinal section along the axial direction. The basic configuration of the immersion nozzle 10A according to this embodiment is the same as that of the first embodiment, so a description will be omitted. The immersion nozzle 10A according to this embodiment differs from the immersion nozzle 10 described in the first embodiment in the configuration relating to the sliding plate 12A and the locking portion 30.

[0026] The sliding plate 12A is configured to have a different center position than the sliding plate 12 described in the first embodiment. As shown in Figure 2, the center of the sliding plate 12 is eccentric from the center of the nozzle bore 13, and the protruding lengths on the left and right sides of the figure are different. In contrast, as shown in Figure 9, the sliding plate 12A is configured so that the center of the nozzle bore 13 and the center of the sliding plate 12A coincide at approximately the same point, and the protruding lengths on the left and right sides of the figure are equal. In other words, the quick-change type continuous casting immersion nozzle 10A equipped with the sliding plate 12A has a sliding plate 12A that protrudes in a circular or square shape, and the center of the sliding plate 12A coincides with the center of the nozzle bore 13. Therefore, when setting it on the guide rail, it can be quickly set without considering the orientation of the immersion nozzle 10A due to the difference in protruding length.

[0027] As shown in Figure 9, the locking portion 30 is composed of a protrusion 31 that extends to a predetermined height along the radial direction of the neck portion 10a. Furthermore, the vertical cross-sectional shape of the protrusion 31 is not limited to the rectangular cross-section shown in Figure 9. That is, the vertical cross-sectional shape of the protrusion may be, for example, a semicircular protrusion 31a shown in Figure 10(a), a trapezoidal protrusion 31b shown in Figure 10(b), or a triangular protrusion 31c shown in Figure 10(c).

[0028] Furthermore, the protrusion 31, which has the above-described vertical cross-sectional shape as the locking portion 30, forms a ridge 32 that is formed to encircle the outer peripheral wall surface in a strip-like manner, as shown in Figure 11. Furthermore, the locking portion 30 in this embodiment is not limited to the protrusion 32. For example, as shown in Figure 12, the locking portion 30 may be an elongated tongue-shaped piece 33 arranged at predetermined intervals along the circumferential direction on the outer peripheral wall surface of the neck portion 10a. Alternatively, as shown in Figure 13, multiple projections 34 of a predetermined shape that protrude radially from the outer peripheral wall surface can be arranged in a row along the circumferential direction or randomly, and the same effect as the above-mentioned ridges 32 and tongue-shaped pieces 33 can be obtained. The projections 34 of a predetermined shape arranged in a row along the circumferential direction may be, for example, the hemispherical projection 34a shown in Figure 13(a), the prismatic projection 34b shown in Figure 13(b), or the triangular pyramidal projection 34c shown in Figure 13(c). In this way, by providing the locking portion 30 at a predetermined position on the outer periphery wall surface of the neck portion 10a, the locking portion 30 can reach deep into the mortar layer that is solidifying. Therefore, the contact area of ​​the mortar with the neck portion 10a can be increased, improving the degree of adhesion of the mortar to the outer periphery wall surface, and thus the mortar can be bonded very firmly to the neck portion 10a. [Examples]

[0029] Next, another embodiment of the immersion nozzle for continuous casting will be described with reference to the attached drawings. Figure 14 is a magnified cross-sectional view showing the portion relating to the gap between the neck and the metal case when the nozzle body is viewed in a longitudinal section along the axial direction. The basic configuration of the immersion nozzle 10B according to this embodiment is the same as that of the first and second embodiments, so a description will be omitted. The immersion nozzle according to this embodiment differs from the immersion nozzle described in the first or second embodiment in the configuration of the locking portion 40.

[0030] As shown in Figure 14, the locking portion 40 is constructed by arranging a rectangular recess 41 cut out to a predetermined depth along the radial direction of the neck portion 10a and a rectangular protrusion 42 projecting to a predetermined height along the radial direction of the neck portion, side by side along the axial direction of the neck portion. Furthermore, the vertical cross-sectional shape of the locking portion 40 is not limited to the cross-section in which a rectangular recess 41 and a protrusion 42 are arranged side by side as shown in Figure 14. That is, the vertical cross-sectional shape of the locking portion 40 may be, for example, a shape in which a protrusion 42a is sandwiched between semicircular recesses 41a, 41a as shown in Figure 15(a), or a shape in which a trapezoidal protrusion 42b is sandwiched between trapezoidal recesses 41b, 41b as shown in Figure 15(b), or a shape in which a trapezoidal protrusion 42c is sandwiched between triangular recesses 41c, 41c as shown in Figure 15(c), or even a cross-sectional shape that is constructed by arbitrarily combining these trapezoidal, triangular, and semicircular cross-sectional shapes.

[0031] Furthermore, the shape of the protrusion 42 sandwiched between the recesses 41, 41 that exhibit the above-described vertical cross-sectional shape as the locking portion 40 is as shown in Figure 16, where the band portion 44 sandwiched between grooves 43, 43 arranged in parallel along the axial direction is formed to circumferentially surround the outer circumferential wall surface of the neck portion 10a. Furthermore, the locking portion 40 in this embodiment is not limited to the grooves 43, 43 and the band portion 44 as shown in Figure 16. That is, when the nozzle body is viewed in cross-section along the axial direction, the shape is such that the protrusions 42 are sandwiched between the recesses 41, 41. For example, as shown in Figure 17, a circumferentially elongated tongue piece 45 is formed to protrude radially from the outer peripheral wall surface of the neck portion 10a, and a plurality of circumferentially elongated slits 46 are formed parallel to the tongue piece 45 above or below it, and these can be arranged at predetermined intervals. In this way, by providing the uneven locking portion 40 at a predetermined position on the outer periphery wall surface of the neck portion 10a, the contact area between the locking portion 40 and the mortar layer can be increased, improving the degree of adhesion of the mortar to the outer periphery wall surface, thereby allowing the mortar to be bonded very firmly to the neck portion 10a.

[0032] According to the continuous casting immersion nozzles 10, 10A, and 10B described in the first to third embodiments, when mortar is filled into the gap 15 formed between the nozzle body and the metal case 11 to fix the metal case 11 to the nozzle body, locking parts 20, 30, and 40 are provided on the neck portion 10a of the nozzle body to increase the contact area of ​​the mortar with the neck portion 10a and improve the degree of adhesion. This prevents the metal case 11 from shifting relative to the nozzle body even after heating such as preheating. Therefore, in the case of the quick-change type immersion nozzles 10, 10A, and 10B shown in the embodiment, they can be smoothly set into the quick changer after preheating. Furthermore, the invention is not limited to the immersion nozzles 10, 10A, and 10B shown in the examples, but can be broadly applied to various nozzles, such as long nozzles for continuous casting in which mortar is used as an adhesive to fix the metal case 11 to the nozzle body. In this case, not only are locking parts 20, 30, and 40 provided on the neck portion 10a, but parts having the same shape as the locking parts 20, 30, and 40 may also be provided at predetermined positions on the body portion 10b, or locking parts may be provided at predetermined positions on both the neck portion 10a and the body portion 10b. In either case, by using mortar as an adhesive and fixing the metal case 11 to the nozzle body, by creating irregularities on the peripheral wall surface of the nozzle body to increase the contact area of ​​the mortar layer, the adhesive strength of the mortar can be maintained even when the mortar expands due to thermal expansion in a high-temperature environment, and the metal case 11 can be held in the predetermined position on the nozzle body before and after heating. [Explanation of Symbols]

[0033] 10, 10A, 10B... Immersion nozzles for continuous casting, 10a...Neck section, 10b...Body section, 10c...Joint section, 11...Metal case, 12,12A...Sliding plate, 13a,13b,13c...Nozzle inner hole, 14...Discharge port, 15...Gap, 20, 30, 40... locking parts, 21...recess, 22...groove, 23...slit, 24...bottomed hole 31...convex part, 32...ridge, 33...tongue, 34...projection, 41...recess, 42...convex part, 43...groove, 44...band part, 45...tongue, 46...slit.

Claims

1. The nozzle body consists of a neck portion that is roughly shaped like an inverted truncated cone and a roughly cylindrical body portion that is integrally connected to the lower end of the neck portion, and a metal case that covers at least the neck portion of the nozzle body. A continuous casting nozzle is provided, wherein a predetermined refractory material with plasticity is filled into the gap formed between the nozzle body and the metal case, thereby fixing the metal case to the nozzle body. A locking portion is provided at a predetermined position on the circumferential wall surface of the neck portion, formed by either a recess that is recessed in the radial direction or a protrusion that is projected in the radial direction, or both, when the circumferential wall surface is viewed in a longitudinal section along the axial direction. A continuous casting nozzle characterized in that the refractory material is locked to the locking portion.

2. The nozzle body has a joint portion equipped with a substantially flat sliding plate, and the lower surface of the joint portion is integrally connected to the upper end surface of the neck portion, in an immersion nozzle, The continuous casting nozzle according to claim 1, characterized in that the metal case covers the neck portion and the joint portion.

3. The continuous casting nozzle according to claim 1, characterized in that the recess is composed of a groove formed along the circumferential direction of the peripheral wall surface.

4. The continuous casting nozzle according to claim 1, characterized in that the protrusion is composed of a ridge formed along the circumferential direction of the peripheral wall surface.

5. The continuous casting nozzle according to claim 1, characterized in that when the nozzle body is viewed in a longitudinal cross-section along the axial direction, the recess and the protrusion are formed to be adjacent to each other in an alternating manner.

6. The continuous casting nozzle according to claim 1, characterized in that the refractory material is mortar.

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