JP3754165B2 - Refractories for side weirs for continuous casting of thin plates - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refractory for a side weir used in a thin plate continuous casting apparatus.
[0002]
[Prior art]
FIG. 3 is a schematic view of a thin plate continuous casting apparatus. Side weirs 1 and 2 of the thin plate continuous casting apparatus are brought into contact with both end surfaces of a pair of rotating cooling drums 3 and 4 and injected from the tundish through a nozzle 5. The molten steel 6 is sealed to prevent leakage from the rotating drum end face.
[0003]
FIG. 4 shows a conventional side weir, FIG. 4-a is a plan view of the side weir, and FIG. 4-b is a side view of the side weir. As disclosed in Japanese Patent No. 90548, the side weir frame 7 includes an indefinite refractory 8, a base member 9, and a ceramic plate 10 fixed to the base member 9. The ceramic plate 10 is rotated. The moving mold is formed by directly contacting both end faces of the drum.
[0004]
Since the material of the ceramic plate 10 is required to have lubricity and wear resistance, and the base member 9 is a material that requires thermal shock and creep resistance characteristics, both functions cannot be satisfied with one material. , Each made from different materials.
[0005]
However, if the ceramic plate 10 is not firmly fixed to the base member 9, the seal is deteriorated, causing leakage steel.
[0006]
Therefore, for example, a structure disclosed in Japanese Patent Laid-Open No. 7-68353 or Japanese Patent Laid-Open No. 7-68352 has been developed. FIG. 5 shows a conventional side dam, FIG. 5-a is an external view of a refractory for the side dam, and FIG. 5-b is a longitudinal sectional view showing the structure of a ceramic plate and a base member, which is disclosed in the publication. The refractory for the side weir has a structure in which the ceramic plate is fixed to the groove of the base member with an adhesive, and between the ceramic plate 10 and the base member 9, the side gap 11 and the bottom gap 12 are inorganic. A base adhesive 9 is filled to fix the base member 9 and the ceramic plate 10.
[0007]
[Problems to be solved by the invention]
However, such side dam refractories have the following problems.
[0008]
As a first problem, in the structure in which the ceramic plate is fixed with the inorganic adhesive in the groove of the base member as disclosed in JP-A-7-68353, the inorganic bonding between the ceramic plate and the base member is performed. The ceramic plate is fixed by the hot adhesive force of the agent. That is, since the ceramic plate is required to have lubricity as a characteristic to be provided, a material such as BN-based carbon is applied. Therefore, the adhesiveness is poor because the reactivity with the inorganic adhesive is low, and since the inorganic adhesive shrinks due to heat from the molten steel during use, there is a gap between the ceramic plate and the base member. The force further decreases with heat. Furthermore, since this joint is also arranged on the molten steel immersion side, molten steel infiltrates into the joint during long-time casting, resulting in poor adhesion. For this reason, the ceramic plate may be displaced or lifted when used for casting for a long time, resulting in poor adhesion to the drum end surface and poor sealing performance. Therefore, molten steel may leak from between the drum end surface and the ceramic plate.
[0009]
As a second problem, in the side weir disclosed in Japanese Patent Laid-Open No. 7-68352, the ceramic plate is broken in the processing operation to polish the surface accuracy of the ceramic plate to 10S in order to improve the sealing performance with the drum end surface. Will occur. When processing the surface of a ceramic plate bonded to a conventional base member, if the adhesive is not uniformly and evenly filled on the back side of the ceramic plate, the ceramic plate will bend due to the pressing force of the grindstone, and a predetermined amount will be generated. Processing accuracy cannot be obtained, and in some cases, damage occurs during processing.
[0010]
Filling the back side with a uniform thickness and evenly with an inorganic adhesive is a rather difficult operation, and good accuracy of the surface polishing of the ceramic plate cannot be obtained, resulting in a high defect rate.
[0011]
The third problem is that the ceramic plate inevitably gets into the gap between the ceramic plate and the ceramic plate that come into contact with each other due to the bonding work with the inorganic adhesive. In this case, burrs are generated, and the burrs adhere to the end surface of the drum and rotate, so that the ceramic plate may be mechanically damaged and lost.
[0012]
As a fourth problem, the operation of bonding the ceramic plate to the base member is disclosed in Japanese Patent Application Laid-Open No. 7-68353, but it is very complicated, and the ceramic plate is divided into many parts as a measure against anti-sboring. When it has a shape, it takes more time for the bonding operation. For this reason, it is a neck work process in terms of manufacturing cost and construction period in manufacturing the side weir.
[0013]
Therefore, the present invention prevents the occurrence of floating and deviation during the casting of the ceramic plate, prevents the precision failure in the surface processing of the ceramic plate, reduces the gap between the ceramic plates in order to eliminate the occurrence of burrs, Provided is a refractory for a side weir for continuous casting of a thin plate having a structure that shortens the working time in the manufacture of a weir.
[0014]
[Means for Solving the Problems]
The refractory for the side weir for continuous casting of the present invention includes a ceramic plate divided into a plurality of pieces and a base member formed of a castable, and the divided ceramic plate forms a base member. The castable is cast into the castable in a state of direct contact with the ceramic plate, the distance between the joint surfaces of the divided ceramic plates is 200 microns or less, and the ceramic plates protrude from the base member at 1 mm or more and 30 mm or less. Features.
[0015]
Moreover, you may provide uneven | corrugated shape in the side surface which contact | connects the same base member of the ceramic plate embed | buried in a base member refractory with the refractory for side dams.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
The ceramic plate is divided into a plurality of parts for the purpose of preventing cracking damage during use due to pressure received from the drum or thermal shock.
[0017]
The material of the ceramic plate is BN material, BN-Si ₃ N ₄ material, BN-ALN material, BN-AlN-Si ₃ N ₄ material, BN-AlN-SiC material due to the wear characteristics when sliding with the cooling drum. _{, BN-Si 3 N 4 -AlN} -SiC material, Al ₂ O ₃ -C material, Al ₂ O ₃ -SiC-C material, MgO-C materials, MgO-SiC-C material, Al ₂ O ₃ -ZrO ₂ such -cr ₂ O ₃ material is used.
[0018]
The ceramic plates are cast on the surface so as to protrude from 1 mm to 30 mm and castable so that the distance between the ceramic plates is 200 microns.
[0019]
The ceramic plate protrudes 1 mm or more from the indeterminate base member toward the working surface, facilitating 10S surface polishing of the ceramic plate surface, and the drum body does not hit the base member when sliding with the end surface of the cooling drum. Only the drum end face can slide with the ceramic plate. Moreover, if it protrudes exceeding 30 mm, the fixing force to a base member will become weak and a ceramic plate will peel off by the frictional force at the time of sliding.
[0020]
If the distance between the bonding surfaces of the ceramic plates exceeds 200 microns, there is a molten steel insertion that causes burrs of the slab during casting, so the distance between the bonding surfaces is preferably 200 microns or less.
[0021]
Since the space between the joint surfaces of the divided ceramic plates is 200 microns or less, the molten steel does not infiltrate. In the prior art, since an adhesive is used, it is not possible to form all the surfaces of 200 microns or less because the adhesive adheres to the gap. In the present invention, the ceramic plates are formed integrally with the irregular base member after the ceramic plates are brought into close contact with each other, and therefore, the bonding surface between the ceramic plates can be easily formed to 200 microns or less.
[0022]
The ceramic plate and the castable are in direct contact with each other without using a filler or the like. As a result, since there is no inorganic adhesive between the ceramic plate and the base member that causes molten steel infiltration or shrinkage due to heat reception of the molten steel, the ceramic plate is not displaced or peeled off.
[0023]
The side surface where the ceramic plate is in contact with the castable is processed to have a concave-convex process, so that the fixing force to the base member is strengthened, and the structure is further prevented from falling off, peeling off or shifting.
[0024]
Castables used in the present invention are usually of ironmaking, it can castable the use of over general used in the steel making process, for example, Al ₂ O ₃ -SiC-C material, Al ₂ O ₃ -C material, Al ₂ O ₃ -SiC material, Al ₂ O ₃ -MgO material and the like can be used.
[0025]
【Example】
1 shows a side dam refractory according to the present invention, FIG. 1-a is a perspective view of a side dam refractory, FIG. 1-b is a longitudinal sectional view showing the structure of a ceramic plate and a base member, and FIG. c is a cross-sectional view of another embodiment of the ceramic plate. A plurality of ceramic plates 10 made of 56 wt% BN-31 wt% AIN-9 wt% SiC material are butted in a Y shape, and 72 wt% of the ceramic plate 10. It has a structure in which an amorphous base member 9 made of% A1 ₂ 0 ₃ -14% by weight SiC-8% weight C is integrated.
[0026]
As seen in the cross-sectional view of FIG. 1-b, the ceramic plate 10 and the irregular base member 9 are integrated with no joints. Also, as shown in the cross-sectional view of FIG. 1-c, by attaching unevenness to the portion embedded in the base member 11 of the ceramic plate 10, the fixing force to the base member 11 is strengthened, and further dropped, peeled off, misaligned, etc. Can be prevented. A heater hole 13 is formed on the side surface of the base member 11.
[0027]
FIG. 2 is a perspective view of an irregular casting metal frame for producing the side dam refractory according to the present invention shown in FIG. 1. The casting metal frame 14 has a Y-shaped groove (concave portion) 15 in which the ceramic plate 10 is disposed at the bottom. There is a heater hole forming metal frame rod hole 17 for holding the heater hole forming metal frame rod 16 on the side surface.
[0028]
A side dam refractory in which a ceramic plate and an irregular base member are integrated is manufactured using the cast metal frame 14. The procedure is to place the ceramic plate with the butt face processed to 10S before pouring the irregular refractory into the Y-shaped groove (recess), and to set the heater forming metal frame rod to the heater hole forming metal frame rod hole After setting, the casted refractory to be used as a base member is poured into a metal frame, and after curing, it is removed from the mold, so that the fixed refractory that has been poured is dry-shrinked and fixed without any joints. A product is formed. Further drying reduces the drying shrinkage and further fixes. Butting of the integrated ceramic plates is 200 microns or less. The ceramic plate protrudes about 4 mm from the base member. Further, in this case, the heater hole is formed by a heater hole forming rod. However, when the preheating method of the side weir is external preheating, it is not necessary to form the heater hole.
[0029]
The casting by the side weir manufactured in this example was capable of continuous casting for 60 minutes or more.
[0030]
The present invention is not limited to the above-described embodiment, and the structure, material, and manufacturing conditions of the refractory for the side weir are cooling drum conditions (material, dimensions, shape, etc. of the end face), side dam conditions (structure, dimensions) , Shape, combination of materials, preheating conditions, etc.), continuous casting conditions (temperature, speed, dimensions, etc.), etc., can be appropriately changed within the scope of the claims of the present invention.
[0031]
【The invention's effect】
The structure of the ceramic plate and the irregular base member of the present invention eliminates chipping of the ceramic plate due to joint damage between the ceramic plate and the base member and eliminates burrs, and further strengthens the adhesion between the ceramic plate and the base member. Will occur. For this reason, it has become possible to perform thin plate continuous casting for a long time (60 minutes or more), which was impossible with the prior art.
[0032]
In addition, it has become possible to provide cheaper and faster lead times than conventional products.
[0033]
Furthermore, by providing unevenness in the portion of the ceramic plate that is buried in the base member, the fixing force to the base member is strengthened, and it is possible to prevent the occurrence of falling off, peeling, displacement and the like.
[Brief description of the drawings]
1 shows a refractory for a side weir according to the present invention, FIG. 1-a is an external view of the refractory for a side weir, FIG. 1-b is a longitudinal sectional view showing the structure of a ceramic plate and a base member, FIG. -C is sectional drawing of the other Example of a ceramic plate.
2 is a perspective view of an irregular casting metal frame for producing the side dam refractory according to the present invention shown in FIG. 1. FIG.
FIG. 3 is a schematic view of a thin plate continuous casting apparatus.
4 shows a conventional side weir, FIG. 4-a is a plan view of the side weir, and FIG. 4-b is a side view of the side weir.
FIG. 5 shows a conventional side dam, FIG. 5-a is a perspective view of a refractory for the side dam, and FIG. 5-b is a longitudinal sectional view showing the structure of a ceramic plate and a base member.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 Side dam 3, 4 Cooling drum 5 Nozzle 6 Molten steel 7 Side dam metal frame 8 Indeterminate refractory 9 Base member 10 Ceramic plate 11 Side surface gap 12 Bottom surface gap 13 Heater hole 14 Cast metal frame 15 Y-shaped groove (Concave)
16 Heater hole forming metal frame rod 17 Heater hole forming metal frame rod hole

Claims (2)

A ceramic plate divided into a plurality of parts and a base member formed of castable,
The ceramic plates divided into a plurality are cast into the castable in direct contact with the castable forming the base member, and the bonding surface between the divided ceramic plates is 200 microns or less. A refractory for a side weir for continuous casting of a thin plate, wherein the plate protrudes from the base member at 1 mm or more and 30 mm or less.   2. A refractory for a side weir for continuous casting of thin plates according to claim 1, wherein a concave and convex shape is provided on a side surface of the ceramic plate in contact with the base member.

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