High-thermal-conductivity unfired alumina-carbon sliding plate brick and preparation method thereof

Abstract

The invention discloses a high-thermal-conductivity unfired Al2O3-C sliding plate brick and a preparation method thereof. The sliding plate brick comprises the following raw materials in parts by mass: 50-75 parts of corundum particles, 10-20 parts of corundum fine powder, 5-10 parts of activated alumina micro powder, 2-5 parts of metal Al powder, 1-3 parts of metal Al fibers, 1-2 parts of elemental Si fibers, 1-3 parts of flake structure Al sheets, 1-3 parts of flake structure Si sheets, 0.5-1.5 parts of Si3N4 fibers, 2-4 parts of SiC fibers, 1-3 parts of high-temperature asphalt powder and 3-6 parts of a binding agent. The preparation method comprises the following steps: uniformly pre-mixing other raw materials except the corundum particles and the binding agent to prepare pre-mixed powder; the preparation method comprises the following steps: mixing and grinding corundum particles, a binding agent and premixed powder, ageing for more than 24 hours, then carrying out compression molding, baking for more than 24 hours at 180-260 DEG C, and directly sleeving a steel belt and a steel shell on the baked sliding plate brick, drilling, polishing and smearing a graphite coating to obtain the high-thermal-conductivity unfired Al2O3-C sliding plate brick.

Description

technical field [0001] The invention relates to the technical field of refractory materials for steelmaking, in particular to a high thermal conductivity non-burning alumina (Al 2 o 3 )-carbon (C) slide brick and preparation method thereof. Background technique [0002] The sliding nozzle refractory is the key component of the ladle flow control system, which plays a role in controlling and regulating the flow of molten steel. The working conditions during its use are very harsh, mainly manifested in: 1) long-term contact with high-temperature molten steel, affected by different chemical components Oxidation, scouring and erosion of molten steel; 2) The sharp change of temperature gradient up to about 1000°C in the process of pouring steel, resulting in huge thermal stress inside the material; 3) The flow of molten steel is controlled by opening and closing the slide plate, and the slide plate pulls the plate back and forth in the process There is a lot of wear between the...

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Problems solved by technology

[0005] 1) Low medium temperature strength: the binder cracks during the use of the skateboard, which reduces the internal bonding strength of the material;

[0006] 2) The problem of roughening and falling blocks on the surface of the slide plate: during the casting process of the slide plate, the periphery of the casting hole is in contact with molten steel, and its temperature is high, which can be sintered to produce greater strength. It cannot yet be melted or reacted to form a combination of ceramics, resulting in low strength in these areas, which causes the problem of roughening and falling off the surface of the slide when the slide is pulled back and forth during opening and closing;

[0007] 3) Poor thermal shock performance: It is difficult to form continuous carbon bonding, metal bonding or ceramic bonding inside the non-burning skateboard during use, so the thermal shock stability is poor;

[0008] 4) The problem of oxidation napping is prominent: the cause is similar to point 2), the temperature of the sliding area and non-sliding area outside the casting hole is low, and the antioxidant is difficult to play a good role, and the carbon source will be significantly oxidized, resulting in the problem of oxidation napping , there will be a risk of steel breakout in severe cases

[0009] In recent years, scientific and technological workers have done a lot of research work on non-burning skateboards, such as invention patent application documents CN106986619 A, CN 103011867 A, CN109400121 A, CN109160807 A, CN 106001532 A, etc. respectively report the introduction of nano-alumina powder into non-burning skateboards body, magnesia, spinel, aluminum titanate, etc. to improve the density, strength, oxidation resistance, thermal shock stability, etc. Low temperature strength and other problems, there will still be problems such as oxidized roughening and sliding board surface falling off during use

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