Plate refractory and slide valve device

Abstract

To provide a plate refractory and a slide valve device which can be manufactured by a relatively simple method and can suppress longitudinal cracks.SOLUTION: A plate refractory includes a body part 2 made of a refractory having a shape capable of distinguishing a longitudinal direction from a transverse direction in a plan view, a through-hole part 3 passing through the body part 2 at a position deviated from the longitudinal center of the body part 2 to one side, and a defective part 4 partially lacking the refractory in the body part 2. In a polar coordinate system in which the center of a through-hole part 3 in a plan view is set as an origin O and an imaginary line extending to the other side in the longitudinal direction is set as a starting line X, a proximal point 41, which is a point at which the distance from the origin O becomes minimum among the defective parts 4, exists in a first region A1 in which the absolute value of the deflection angle is 30° or more and 70° or less or a second region A2 in which the absolute value of the deflection angle is 110° or more and 150° or less, and a length of the defective part 4 along a third direction orthogonal to the longitudinal direction and the transverse direction is 4.0 mm or more.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a plate refractory and a slide valve device used for adjusting the flow rate of molten metal, etc. [Background technology]

[0002] A slide valve device is widely used as an outlet for flowing molten metal from a vessel such as a ladle or a tundish. The slide valve device includes a plurality of refractory plates that can slide relative to each other, and realizes flow rate control of the molten metal by adjusting the relative positions of through holes provided in each refractory plate.

[0003] When molten metal flows through the through-hole of the plate refractory, a temperature difference occurs between the periphery of the through-hole and the other parts. This temperature difference causes thermal stress and may cause cracks in the plate refractory. In particular, when a crack running in the sliding direction of the plate refractory (called a "vertical crack") occurs, the crack will occur at a position where it may come into contact with the flowing molten metal, and the plate refractory is likely to be damaged from the crack.

[0004] Non-Patent Document 1 examines the difference in crack occurrence behavior due to differences in fixing methods in a slide valve device for plate refractory materials in which iron bands are shrink-fitted to suppress cracks. Non-Patent Document 1 reports that vertical cracks are less likely to occur when the plate refractory material is restrained on four sides not including the sliding direction, and that vertical cracks are less likely to occur when the restraining position is brought closer to the through-hole of the plate refractory material.

[0005] Furthermore, Patent Document 1 discloses a plate refractory material in which a recess is provided on the outer periphery of the plate refractory material, thereby enabling the position of four-side restraint to be brought closer to the through-hole portion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2014-503364 [Non-patent literature]

[0007] [Non-Patent Document 1] Refractories, 1997, Vol. 49, No. 6, pp. 349-354 Summary of the Invention [Problem to be solved by the invention]

[0008] However, when trying to suppress vertical cracks according to the technical idea disclosed in Non-Patent Document 1, the restraining surface of the plate is arranged in a direction significantly different from the sliding direction of the plate. In other words, the angle that the restraining surface makes with the load direction becomes small, and the restraining force needs to be considerably large to securely fix the plate. Therefore, a large force is required to remove the plate refractory, and the replacement work of the plate refractory may be difficult. This problem can be alleviated by adding some ingenuity to the shape of the plate refractory as in the technology of Patent Document 1, but on the other hand, there is a problem that the required level of processing accuracy of the plate refractory is high.

[0009] Therefore, there is a need to develop a plate refractory and a slide valve device that can be manufactured by a relatively simple method and that can suppress vertical cracks. [Means for solving the problem]

[0010] The plate refractory according to the present invention comprises a refractory body having a shape that allows a distinction between a longitudinal direction and a lateral direction in a plan view, a through hole portion penetrating the body portion at a position offset to one side from the center of the longitudinal direction of the body portion, and a defective portion in which the refractory is partially missing from the body portion, wherein in a polar coordinate system with the center of the through hole portion in the plan view as the origin and a virtual line extending to the other side in the longitudinal direction as the initial line, a proximal point of the defective portion, which is a point that is a shortest distance from the origin, is located in a first region where the absolute value of the deflection angle is 30° or more and 70° or less, or in a second region where the absolute value of the deflection angle is 110° or more and 150° or less, and the length of the defective portion along a third direction perpendicular to the longitudinal direction and the lateral direction is 4.0 mm or more.

[0011] The slide valve device of the present invention comprises a first plate refractory which is the above-mentioned plate refractory, and a second plate refractory which is a plate refractory having a second main body portion made of a refractory material having a shape which allows a distinction between the longitudinal direction and the lateral direction in a plan view, and a second through hole portion which penetrates the main body portion at a position offset to one side from the center of the longitudinal direction of the main body portion, and is characterized in that the lateral range of the defective portion in the first plate refractory does not overlap with the lateral range of the second through hole portion in the second plate refractory.

[0012] According to these configurations, since the crack can be guided in the direction where the defect exists, it is easy to suppress vertical cracks. Also, since it is possible to manufacture a refractory with a part of the defect by a conventional method, it is relatively easy to manufacture the plate refractory and the slide valve device of the above configuration. Furthermore, according to the slide valve device of the above configuration, since the defect of the plate refractory is unlikely to come into contact with the molten metal, it is easy to prevent the intrusion of the molten metal.

[0013] Preferred embodiments of the present invention will be described below. However, the scope of the present invention is not limited to the preferred embodiments described below.

[0014] In one aspect of the plate refractory according to the present invention, it is preferable that a range of the through hole portion in the lateral direction does not overlap a range of the defective portion in the lateral direction.

[0015] According to this configuration, the defective portion is unlikely to come into contact with the molten metal, making it easier to prevent the molten metal from entering.

[0016] In one aspect of the plate refractory according to the present invention, the length of the missing portion along the third direction is preferably 30% or more of the length of the main body along the third direction.

[0017] With this configuration, the defect portion is more likely to exhibit the effect of inducing cracks.

[0018] In one aspect of the plate refractory according to the present invention, in the polar coordinate system, the distance between the proximal point and a distal point, which is the point of the missing portion that is the farthest from the origin, is preferably 2.0 mm or more.

[0019] With this configuration, the defective portion is more likely to induce cracks.

[0020] In one aspect of the plate refractory according to the present invention, in the polar coordinate system, it is preferable that the deflection angle between the proximal point and a distal point, which is a point of the missing portion that is farthest from the origin, coincide with each other.

[0021] This configuration tends to increase the effect of the defective portion in inducing cracks.

[0022] In one embodiment of the plate refractory according to the present invention, the missing portion is preferably spaced from the outer periphery of the main body by 5.0 mm or more in a plan view.

[0023] With this configuration, the defective portion is less likely to become a cause of outside air inflow.

[0024] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which are given with reference to the drawings. [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a plan view of the plate refractory according to the embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 11 is a plan view of a plate refractory material according to a modified example. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Diagram 5] 1 is a side cross-sectional view of a slide valve device according to an embodiment. [Figure 6] FIG. 2 is a schematic plan view showing a fully closed state of the slide valve device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] An embodiment of a plate refractory and a slide valve device according to the present invention will be described with reference to the drawings. In the following, an example in which the plate refractory according to the present invention is applied to a plate refractory 1 used in a slide valve device 10 will be described.

[0027] [Configuration of plate refractory material] The plate refractory 1 includes a body 2 made of refractory material, a through hole 3 penetrating the body 2, and a missing portion 4 where the body 2 is partially lacking in refractory material (FIGS. 1 and 2).

[0028] The main body 2 is a plate-shaped member made of a refractory material. As the refractory material constituting the main body 2, a dense refractory material conventionally applied to a plate refractory material for continuous casting can be used. As the dense refractory material, a dense refractory material normally used in this field can be used, and as the base material thereof, various materials can be exemplified, such as oxide-based materials generally used as refractories such as alumina, mullite, spinel, magnesia, and zirconia, and materials combining these oxides with non-oxides such as carbon.

[0029] In a plan view (FIG. 1), the main body 2 has a rectangular shape with four chamfered corners, so that the main body 2 has a shape that allows a distinction between the long side (left-right direction on the paper in FIG. 1) and the short side (up-down direction on the paper in FIG. 1) in the plan view.

[0030] The through-hole portion 3 is a hole portion that penetrates the main body portion 2. The direction in which the through-hole portion 3 penetrates the main body portion 2 is the thickness direction (one example of a third direction) of the main body portion 2, which is a plate-like member, and is a direction perpendicular to the above-mentioned longitudinal direction and lateral direction (direction perpendicular to the paper surface of FIG. 1). In this embodiment, the through-hole portion 3 is a circle with a diameter of 80 mm in a plan view. Note that protrusions are provided around the through-hole portion 3 for connecting to a lower nozzle N2 (described later).

[0031] In the plan view (FIG. 1), the through-hole portion penetrates the main body portion 2 at a position offset to one side from the center in the longitudinal direction of the main body portion 2. In this embodiment, an example is shown in which the through-hole portion 3 is provided at a position offset to the left side from the center in the longitudinal direction in FIG.

[0032] The defective portion 4 is a portion where the refractory is partially missing in the main body 2. The defective portion 4 is provided in the form of, for example, a through hole penetrating in the thickness direction from the upper surface to the lower surface of the main body 2, a recess provided in a manner that does not penetrate in the thickness direction from the upper surface or the lower surface of the main body 2, and a gap that does not open to either the upper surface or the lower surface of the main body 2, and in any case, the length of the defective portion 4 along the third direction is 4.0 mm or more. In this embodiment, an example in which the defective portion 4 is provided in the form of a through hole is shown.

[0033] The shape of the cutout 4 in the plan view (FIG. 1) is not particularly limited, and may be any shape, such as a circle, an ellipse, an oval, a rectangle, a polygon, a straight line, a curved line, a wavy line, or a combination of these. Note that a plurality of cutouts 4 may be provided, and in this case, the shapes of the plurality of cutouts 4 may be selected independently. In this embodiment, an example in which two circular cutouts 4 are provided in the plan view is shown.

[0034] Next, the position of the defect portion 4 will be described. As a prerequisite, a polar coordinate system expressing the position of the defect portion 4 is defined. The position of the defect portion 4 is expressed in a polar coordinate system in which the center of the through-hole portion 3 in the plan view is the origin O, and a virtual line extending to the other side in the longitudinal direction is the initial line X (FIG. 1). In this embodiment, since the through-hole portion 3 is circular in the plan view, the center of the through-hole portion 3 is the center of the circle, which becomes the origin O of the polar coordinate system. Note that, if the through-hole portion is a figure that is not circular in the plan view, the geometric center of the figure becomes the origin of the polar coordinate system. In addition, in this embodiment, since the through-hole portion 3 is provided at a position shifted to the left in FIG. 1, the initial line X extends from the origin O to the right in FIG. 1.

[0035] The missing portion 4 is provided so that the proximal point 41, which is the point of the missing portion 4 that is the shortest distance from the origin, is present in the first region A1 where the absolute value of the deflection angle is 30° or more and 70° or less (FIG. 1). Since the first region A1 is defined by the absolute value of the deflection angle, one first region A1 exists above and one below the initial line X as shown in FIG. 1. In this embodiment, two missing portions 4 are provided in each of the two first regions A1. The missing portion 4 may be provided so that the proximal point 41 is present in the second region A2 (FIG. 1) where the absolute value of the deflection angle is 110° or more and 150° or less. This point will be described later as a modified example. In FIG. 1, the straight lines that define the first region A1 and the second region A2 are shown with the value of the deflection angle θ.

[0036] By providing the defective portion 4 in the first region A1 or the second region A2, it is possible to guide cracks occurring in the main body portion 2 to the first region A1 and the second region A2. This makes it easier to prevent cracks from running in the longitudinal direction of the main body portion 2 (generation of vertical cracks).

[0037] In this embodiment, the cutout 4 is provided at a position where the range Y1 in the short-side direction of the through-hole portion 3 does not overlap with the range Y2 in the short-side direction of the cutout 4. The range Y1 and the range Y2 are preferably spaced apart by 3.0 mm or more.

[0038] In this embodiment, the defect portion 4 is a circle having a diameter of 4.0 mm in a plan view. Therefore, the proximal point 41 is the point closer to the origin O of the polar coordinate system, among the two intersection points between the line L1 connecting the origin O of the polar coordinate system and the center of the defect portion 4 and the circumference of the defect portion 4. The distal point 42, which is the point of the defect portion 4 that is the longest distance from the origin, is the point farthest from the origin O of the two intersection points. As is clear from the above relationship, the proximal point 41 and the distal point 42 are both on the line L1, and therefore the deviation angles of the two points are the same.

[0039] Moreover, the distance between the proximal point 41 and the distal point 42 is 4.0 mm, which is the same as the diameter of the defect 4. As in this example, if the distance between the proximal point 41 and the distal point 42 is 2.0 mm or more, the defect 4 is more likely to induce cracks, which is preferable.

[0040] In the plan view (FIG. 1), the cutout 4 is provided in an area 5.0 mm or more inward from the outer periphery of the main body 2. As in this example, if the cutout 4 is spaced 5.0 mm or more away from the outer periphery of the main body 2, it is preferable because it is easy to prevent a decrease in strength of the main body 2 caused by the cutout 4 and it is easy to prevent outside air from entering from the outer periphery of the main body 2 via the cutout 4.

[0041] [Method of manufacturing plate refractory] The plate refractory 1 according to the present embodiment can be manufactured by a known manufacturing method for refractory members. That is, a mixed material obtained by mixing desired materials in a desired mass ratio is molded into a plate shape to obtain a preform, and then the preform is fired to obtain the plate refractory 1. As for the through hole portion 3 and the defect portion 4 (hereinafter referred to as the defect portion 4, etc.), a method of manufacturing a plate-shaped refractory without the defect portion 4, etc., and then removing the refractory from the portion corresponding to the defect portion 4, etc., a method of providing a protrusion or the like corresponding to the defect portion 4, etc. on a mold used for molding the preform, a method of forming the portion corresponding to the defect portion 4, etc. of the preform with a burnt-out material that is burnt-out by firing (the burnt-out material is burnt out after firing to form a space corresponding to the defect portion 4, etc.), etc. can be exemplified.

[0042] [Modification of plate refractory] Next, modified examples of the missing portion will be described. Note that the configurations of the main body 2 and the through-hole 3, the definitions of the longitudinal direction, the lateral direction, and the thickness direction (third direction), and the definition of the polar coordinate system are the same as those in the above embodiment.

[0043] The plate refractory 1A according to the modification (FIGS. 3 and 4) has four elliptical cutouts in a plan view (FIG. 3). Two of the cutouts 5 are provided so that their proximal points 51 are in the first region A1, and the remaining two cutouts 6 are provided so that their proximal points 61 are in the second region A2. That is, in this modification, the four cutouts 5 and 6 are provided, one on each of the four sides of the through-hole portion 3.

[0044] Not only the proximal point 51 but the entire defect 5 is present in the first region A1. Meanwhile, a portion of the defect 6 is outside the second region A2. Thus, as long as the proximal point is in the first region A1 or the second region A2, a portion of the defect may be outside the first region A1 or the second region A2.

[0045] In the plan view (FIG. 3), the major axis of the ellipse of the defect 5 is on the line L2 connecting the origin O of the polar coordinate system and the proximal point 51. Therefore, the distal point 52 of the defect 5 is also on the line L2, and the deviation angles between the proximal point 51 and the distal point 52 are the same. On the other hand, the major axis of the ellipse of the defect 6 is not on the line L3 connecting the origin O and the proximal point 61. Therefore, the distal point 62 of the defect 6 is not on the line L3, and the deviation angles between the proximal point 61 and the distal point 62 do not match. In this way, it is arbitrary whether the deviation angles between the proximal point and the distal point of the defect match or not.

[0046] The defects 5 and 6 are recesses provided in a manner that does not penetrate from the lower surface (the lower surface in FIG. 4) of the main body 2 in the thickness direction (FIG. 4). The depth Z of this recess (an example of the length of the defect along the third direction) is 50% of the thickness H of the main body 2 at the portion where the defects 5 and 6 are provided (an example of the length of the main body along the third direction). As in this example, if the length of the defect along the third direction is 30% or more of the length of the main body, the effect of the defect inducing cracks is easily manifested, which is preferable. Note that, when multiple defects are provided in the form of recesses, the depths (the length of the defect along the third direction) of the respective defects may be the same or different from each other.

[0047] In this modified example, the defect 5 is filled with mortar M (FIG. 4). As in this example, the defect may be filled with a material other than refractory. Even if a material other than refractory is filled, the structure is still one in which the refractory is partially missing, and has the effect of inducing cracks as a discontinuous part in the main body 2. Examples of materials that can be filled in the defect include, but are not limited to, graphite paste, metal paste, and glaze, in addition to mortar. Some of these fillers have the effect of blocking the intrusion of outside air by sealing the gap caused by the defect itself or the induced cracks, and the effect of reinforcing the plate refractory, and can be used appropriately depending on the purpose.

[0048] [Embodiment of Slide Valve Device] Next, an embodiment of the slide valve device 10 will be described. The slide valve device 10 includes a plate refractory 1 (an example of a first plate refractory) and a second plate refractory 11, and an iron band 14 is attached to the plate refractory 1 and the second plate refractory 11 (FIG. 5). The second plate refractory 11 is connected to an upper nozzle N1 through which molten steel tapped from a ladle (not shown) flows, and the plate refractory 1 is connected to a lower nozzle N2 that guides the molten steel to a tundish (not shown). Note that, as materials constituting the second plate refractory 11, the upper nozzle N1, and the lower nozzle N2, known refractory materials are used as materials constituting the respective parts.

[0049] The second plate refractory 11 has a shape similar to that of the plate refractory 1, but does not have a missing portion. That is, the second plate refractory 11 has a second main body portion 12 and a second through hole portion 13, and the dimensions of each portion are similar to those of the main body portion 2 and the through hole portion 3 of the plate refractory 1. The second plate refractory 11 and the plate refractory 1 are combined alternately. That is, the through hole portion 3 of the plate refractory 1 is provided at a position offset to the left side of FIG. 5, while the second through hole portion 13 of the second plate refractory 11 is provided at a position offset to the right side of FIG. 5. The molten steel flowing through the slide valve device 10 flows from the top to the bottom of FIG. 5. Therefore, the second plate refractory 11 is provided on the upstream side of the plate refractory 1.

[0050] The second through-hole portion 13 of the second plate refractory 11 communicates with the upper nozzle N1 and functions as a passage for molten steel. Similarly, the through-hole portion 3 of the plate refractory 1 communicates with the lower nozzle N2 and functions as a passage for molten steel.

[0051] The slide valve device 10 is a device that adjusts the relative position between the second through hole portion 13 and the through hole portion 3 by sliding the plate refractory 1 (and the lower nozzle N2) against the second plate refractory 11, thereby adjusting the flow rate of molten steel. Specifically, the relative position between the second plate refractory 11 and the plate refractory 1 can be arbitrarily selected between a fully closed state (FIG. 6) in which the second through hole portion 13 and the through hole portion 3 have no overlapping portion in a plan view, and a fully open state in which the second through hole portion 13 and the through hole portion 3 coincide in a plan view, and is usually used in a state in which the second through hole portion 13 and the through hole portion 3 partially overlap in a plan view (FIG. 5).

[0052] In this embodiment, the defective portion 4 is provided at a position where the range Y1 in the short-side direction of the through-hole portion 3 does not overlap with the range Y2 in the short-side direction of the defective portion 4 (FIG. 1). In addition, the range in the short-side direction of the second through-hole portion 13 of the second plate refractory 11 does not overlap with the range in the short-side direction of the defective portion 4 of the plate refractory 1 (FIG. 6). Therefore, the defective portion 4 is provided avoiding a portion that may face the second through-hole portion 13 of the second plate refractory 11 due to the sliding action of the plate refractory 1. As a result, the defective portion 4 is unlikely to come into contact with the molten steel filling the second through-hole portion 13, so that it is easy to prevent the molten steel from entering the main body portion from the defective portion 4.

[0053] Other embodiments Finally, other embodiments of the plate refractory and the slide valve device according to the present invention will be described. Note that the configurations disclosed in the following respective embodiments can be combined with the configurations disclosed in other embodiments as long as no contradiction occurs.

[0054] In the above embodiment, a configuration has been described as an example in which the cutout 4 is provided at a position where the short-side range Y1 of the through-hole portion 3 does not overlap with the short-side range Y2 of the cutout 4. However, in the present invention, the short-side range of the through-hole portion and the short-side range of the cutout may overlap.

[0055] In the above embodiment, the slide valve device 10 including two plate refractories, the plate refractory 1 having the missing portion 4 and the second plate refractory 11 having no missing portion, has been described as an example. However, the number of plate refractories according to the present invention is not limited. For example, in the case where three plate refractories are included, that is, a plate refractory connected to an upper nozzle, a plate refractory connected to a lower nozzle, and a plate refractory slidably installed between them, any one of the plate refractories being the plate refractory according to the present invention is also an embodiment of the present invention.

[0056] In addition, in the above embodiment, a configuration in which only one of the two plate refractories included in the slide valve device 10 (plate refractory 1) has a missing portion 4 has been described as an example, but the number of plate refractories according to the present invention among the multiple plate refractories included in the slide valve device is not limited.

[0057] Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereto. A person skilled in the art would easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention. EXAMPLES

[0058] The present invention will be further described below with reference to examples, but the present invention is not limited to the following examples.

[0059] Example 1 A plate refractory was created with one defect in each of the two first regions. However, the thickness H of the main body was set to 40 mm, the diameter D of the through hole was set to 80 mm, and the defect was a circular through hole with a diameter of 2.0 mm. Since the defect was a through hole, the length Z of the defect was 40 mm, the same as the thickness H of the main body. In addition, the proximal point of the defect was set to the position (r, θ) = (71, 45°) in the polar coordinate system. The distance from the starting line of this proximal point was 50 mm.

[0060] Next, a slide valve device having the same configuration as the above embodiment (FIGS. 5 and 6) was produced using a plate refractory. A refractory having the same dimensions as the plate refractory except that it does not have a defective portion was used as a fixed plate refractory to be combined with the plate refractory of Example 1. In addition, the thickness of the iron band attached to the outer periphery of the plate refractory and the fixed plate refractory was set to 4.5 mm, and a load of 1 MPa was applied to the chamfered portions on all four sides of each plate refractory to restrain it.

[0061] The slide valve device described above was used as a slide valve device attached to the bottom of a ladle. The device was used multiple times, counting the number of times the device was used until all the molten steel filled in the ladle was discharged, and the number of times the device was used until it was determined that it was unusable due to damage was counted. In Example 1, the device was used 8 times until it was determined that it was unusable.

[0062] Example 2 Except for forming the defective portion as a circular through hole having a diameter of 4.0 mm, the test was carried out under the same conditions as in Example 1. In Example 2, the number of uses until it was determined that it was unusable was 8 times.

[0063] Example 3 The test was performed under the same conditions as in Example 1, except that the defect was a circular through hole with a diameter of 4.0 mm, and the proximal point of the defect was located at (r, θ) = (85, 45°) in the polar coordinate system. In this case, the distance from the starting line to the proximal point was 60 mm. In Example 3, the number of uses until it was determined that it was unusable was 8 times.

[0064] Example 4 The test was carried out under the same conditions as in Example 1, except that the recess was a circular recess having a diameter of 4.0 mm and a length Z of 25 mm. In Example 4, the number of uses until it was determined that it was unusable was 8 times.

[0065] Example 5 The test was performed under the same conditions as in Example 1, except that the proximal point of the defect was set at a position of (r, θ) = (87, 35°) in the polar coordinate system. In this case, the distance from the starting line of the proximal point was 50 mm, which is the same as in Example 1. In Example 5, the number of uses until it was determined to be unusable was 8 times.

[0066] Example 6 The test was performed under the same conditions as in Example 1, except that the proximal point of the defect was set at a position of (r, θ) = (61, 55°) in the polar coordinate system. In this case, the distance from the starting line of the proximal point was 50 mm, which is the same as in Example 1. In Example 6, the number of uses until it was determined to be unusable was 8 times.

[0067] Example 7 The test was conducted under the same conditions as in Example 1, except that the defect was an elliptical through hole with a major axis of 8 mm and a minor axis of 2 mm. The defect was arranged so that the major axis of the defect was on the line connecting the origin of the polar coordinate system and the proximal point. In Example 7, the number of uses until it was determined that it was unusable was 8 times.

[0068] Example 8 The test was performed under the same conditions as in Example 1, except that the defect was a rectangular through hole with a long side of 8 mm and a short side of 2 mm, and the proximal point of the defect was located at (r, θ) = (78, 50 °) in the polar coordinate system. The defect was arranged so that the long side of the defect was parallel to the straight line connecting the origin of the polar coordinate system and the proximal point. In this case, the distance from the starting line of the proximal point was 50 mm, which is the same as in Example 1. In Example 8, the number of uses until it was determined that it was unusable was 8 times.

[0069] Example 9 Except for forming the defective portion as a rectangular through hole with a long side of 40 mm and a short side of 2 mm, the test was carried out under the same conditions as in Example 8. In Example 9, the number of uses until it was determined that it was unusable was 8 times.

[0070] Example 10 The test was conducted under the same conditions as in Example 9, except that the defect was filled with mortar. The defect was arranged so that the long side of the defect was parallel to the straight line connecting the origin of the polar coordinate system and the proximal point. In this case, the distance from the starting line of the proximal point was 50 mm, which is the same as in Example 1. In Example 10, the number of uses until it was determined that it was unusable was 8 times.

[0071] Example 11 Except for forming the defective portion as a circular through hole having a diameter of 1.0 mm, the test was carried out under the same conditions as in Example 1. In Example 11, the number of uses until it was determined that it was unusable was 7.

[0072] Example 12 The test was performed under the same conditions as in Example 1, except that the defect was a circular through hole with a diameter of 4.0 mm and the proximal point of the defect was located at (r, θ) = (42, 45°) in the polar coordinate system. In this case, the distance from the starting line to the proximal point was 30 mm. In Example 12, the number of uses until it was determined that it was unusable was 7 times.

[0073] Example 13 The test was carried out under the same conditions as in Example 1, except that the recess was a circular recess having a diameter of 4.0 mm and a length Z of 10 mm. In Example 13, the number of uses until it was determined that it was unusable was 7.

[0074] Comparative Example 1 Except for the structure having no missing portion, the test was carried out under the same conditions as in Example 1. In Comparative Example 1, the number of uses until it was determined to be unusable was six.

[0075] Comparative Example 2 The test was performed under the same conditions as in Example 1, except that the defect was a circular through hole with a diameter of 4.0 mm, and the proximal point of the defect was located at a position of (r, θ) = (118, 25°) in the polar coordinate system. In this case, the distance from the starting line of the proximal point was 50 mm, which is the same as in Example 1. In Comparative Example 2, the proximal point of the defect is in an area that does not fall into either the first area or the second area. In Comparative Example 2, the number of uses until it was determined that it was unusable was 6 times.

[0076] Comparative Example 3 The test was performed under the same conditions as in Example 1, except that the defect was a circular through hole with a diameter of 4.0 mm, and the proximal point of the defect was located at a position of (r, θ) = (52, 75°) in the polar coordinate system. In this case, the distance from the starting line of the proximal point was 50 mm, which is the same as in Example 1. In Comparative Example 3, the proximal point of the defect is in an area that does not fall into either the first area or the second area. In Comparative Example 3, the number of uses until it was determined that it was unusable was 6 times.

[0077] Comparative Example 4 Except for the fact that the recess was a circular recess having a diameter of 4.0 mm and a length Z of 3 mm, the test was carried out under the same conditions as in Example 1. In Comparative Example 4, the number of uses until it was determined that it was unusable was 6.

[0078] 〔result〕 As is clear from the above examples and comparative examples, in examples 1 to 13 in which the position and size of the defect portion are within a specific range, the life of the plate refractory was longer than in comparative example 1 in which no defect portion was provided and comparative examples 2 to 4 in which at least one of the position and size of the defect portion is outside the specific range. It was shown that the life of the plate refractory can be extended by providing a defect portion that satisfies the conditions found by the present inventors.

[0079] Table 1: Examples 1 to 6 [Table 1]

[0080] Table 2: Examples 7 to 13 [Table 2]

[0081] Table 3: Comparative Examples [Table 3] [Industrial Applicability]

[0082] INDUSTRIAL APPLICABILITY The present invention can be utilized as a slide valve device used in casting, and a plate refractory material included in the slide valve device, for example. [Explanation of symbols]

[0083] 1: Plate refractory 1A: Plate refractory (variation) 2: Main body 3: Through hole 4: Defective area 41: Proximal point 42: Distal point 5: Missing part (modified form) 51: Proximal point 52: Distal point 53: Mortar 6: Defective part (variation) 61: Proximal point 62: Distal point A1:First area A2:Second area O: Origin of the polar coordinate system X: The starting line of the polar coordinate system 10: Slide valve device 11: Second plate refractory 12:Second body part 13:Second through hole section 14: Iron band N1: Upper nozzle N2: Lower nozzle

Claims

1. A refractory body having a shape that allows a distinction between a longitudinal direction and a lateral direction in a plan view; a through hole portion penetrating the main body portion at a position offset to one side from a center of the main body portion in the longitudinal direction; A missing portion in which the refractory material is partially missing in the main body portion, In a polar coordinate system in which the center of the through hole portion in a plan view is the origin and a virtual line extending to the other side in the longitudinal direction is the starting line, a proximal point, which is a point in the missing portion that is the shortest distance from the origin, is present in a first region where the absolute value of the deflection angle is 30° or more and 70° or less, or in a second region where the absolute value of the deflection angle is 110° or more and 150° or less, The length of the missing portion along a third direction perpendicular to the longitudinal direction and the lateral direction is 4.0 mm or more, In a plan view, the missing portion is spaced from the outer periphery of the main body by 5.0 mm or more.

2. The plate refractory material according to claim 1 , wherein a range of the through hole portion in the lateral direction does not overlap a range of the defective portion in the lateral direction.

3. The plate refractory material according to claim 1 or 2, wherein a length of the recess along the third direction is 30% or more of a length of the main body along the third direction.

4. 3. The plate refractory material according to claim 1, wherein in the polar coordinate system, a distance between the proximal point and a distal point, which is a point of the missing portion that is the farthest from the origin, is 2.0 mm or more.

5. 3. The plate refractory material according to claim 1, wherein, in the polar coordinate system, an angle between the proximal point and a distal point, which is a point of the missing portion that is farthest from the origin, coincides with an angle between the proximal point and a distal point of the missing portion.

6. A first plate refractory, which is the plate refractory according to claim 1 or 2; and A second plate refractory material having a second main body portion made of a refractory material having a shape that allows a distinction between a longitudinal direction and a lateral direction in a plan view, and a second through-hole portion penetrating the main body portion at a position shifted to one side from a center of the main body portion in the longitudinal direction, a widthwise range of the defective portion in the first refractory plate and a widthwise range of the second through hole portion in the second refractory plate do not overlap each other.

Images