Low-expansion high-fracture-resistance tundish retaining wall castable

Abstract

The invention relates to the technical field of tundish working layer refractory materials, in particular to a low-expansion high-fracture-resistance tundish retaining wall castable. The raw material components comprise, by mass, 13 to 16% of 85 alumina with a particle size of 15 to 8 mm, 13 to 16% of 85 alumina with a particle size of 8 to 5 mm, 6 to 8% of 85 alumina with a particle size of 5 to 3 mm, 6 to 10% of 85 alumina with a particle size of 3 to 1 mm, 5 to 10% of 85 alumina with a particle size of 1 to 0 mm, 6 to 10% of 91 magnesia with a particle size of 5 to 3 mm, 6 to 10% of 91 magnesia with a particle size of 3 to 1 mm, 4 to 9% of 95 magnesia with a particle size of 1 to 0 mm, 3 to 5% of 95 magnesia with a particle size of 200 meshes, 10 to 13% of white corundum dedusting powder and 2 to 5% of chrome corundum waste. The invention relates to a low-expansion-coefficient refractory castable which comprises the following components in percentage by weight: 2% of silica powder, 1-2% of aluminum oxide, 0.2-0.5% of 71 cement, 0.2-0.3% of sodium dihydrogen phosphate, 0.05-0.1% of sodium tripolyphosphate, 0.1-0.3% of organic fibers and 1-1.5% of steel fibers. Compared with the prior art through design, the low-expansion-coefficient refractory castable has the advantages of low expansion coefficient, high breaking strength, moderate cost and molten steel purification function.

Description

technical field [0001] The invention relates to the technical field of tundish working layer refractory materials, in particular to a low-expansion and high-flexural-resistance tundish retaining wall castable. Background technique [0002] The tundish retaining wall plays an extremely key role in the configuration of the tundish refractory. Its main function is to eliminate the slow flow area or stagnation area of ​​the molten steel in the tundish, adjust the flow field of the molten steel, and make the molten steel flow along the interface of the steel slag. , shorten the floating time and distance of harmful inclusions in molten steel, which is beneficial to purify molten steel and slow down the fluctuation of molten steel temperature in different parts of the tundish. During use, the retaining wall is immersed in molten steel as a whole, and the temperature is higher than 1500°C or even 1550°C. At the same time, it is impacted by the pressure difference of molten steel on...

AI Technical Summary

Problems solved by technology

Therefore, the existing tundish retaining wall is mainly made of bauxite particles-corundum powder series, which is prefabricated by adding a small amount of binder and adjusting components, and can be used online after baking. The advantage is high temperature conditions The lower strength is relatively high, but the disadvantage is that the cost is relatively high, and it does not have the effect of purifying molten steel, and even brings new impurities into molten steel

[0003] However, the bauxite / magnesia composite tundish retaining wall castable has the disadvantage of large high-temperature linear expansion coefficient, especially in the case of relatively large retaining walls, and the addition of low-cost magnesia is limited. It will lead to a sharp decrease in high-temperature strength, and accidents such as fracture and collapse will easily occur during use, which will bring great safety hazards. In the event of an accident, a large amount of molten steel will be polluted and the loss will be large

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