Non-carbonaceous brick for ultra-low carbon steel external refining steel ladle and preparation method of non-carbonaceous brick

Abstract

The invention discloses a non-carbonaceous brick for an ultra-low carbon steel external refining steel ladle and a preparation method of the non-carbonaceous brick. The non-carbonaceous brick is made of aggregate, a powder material and a binding agent, wherein the aggregate is corundum of which the particle size is greater than 0.088 mm and smaller than or equal to 5 mm; the particle size of the powder material is smaller than or equal to 0.088 mm; the binding agent is a non-phosphorus binding agent consisting of organic binding agents and inorganic binding agents. The non-carbonaceous brick has the advantages that firstly, no carbon or phosphorus is used, and requirements that carbon or phosphorus is not increased to molten steel by working layer materials of a steel ladle melting tank area of low and super-low carbon steel in the external refining process, and the service life is long are met; secondly, the production efficiency of the non-carbonaceous brick is greatly improved, the production cycle is shortened, the supply capability is greatly improved, and organic combination of improvement of production efficiency and prolonging of service lives of non-carbonaceous bricks is achieved.

Description

technical field [0001] The invention relates to a refractory material, in particular to a carbon-free brick for ultra-low carbon steel out-of-furnace refining ladle and a preparation method thereof. Background technique [0002] The ladle is an important container for holding and transporting molten steel and for refining outside the furnace. The chemical composition of the lining material of the ladle directly affects the purity of the molten steel after refining outside the furnace. Most of the working lining materials in the molten pool area of ​​the ladle are mainly magnesia-aluminum-carbon or aluminum-magnesium-carbon bricks with a C content of more than 8.0%. Part of C in it dissolves into the molten steel and has a carburizing effect on the molten steel. The carburizing effect of the working layer material in the ladle molten pool area on the molten steel seriously restricts the smelting of ultra-low carbon steel and other pure steels. It is urgent to reduce the C co...

AI Technical Summary

Problems solved by technology

[0005] Although pouring carbon-free bricks has been successfully applied in large ladles, the casting process has the following disadvantages: firstly, the production efficiency of pouring prefabricated blocks is low, and a large number of molds and large production sites are required; secondly, production, delivery The delivery cycle is long, and it generally takes 20-30 days to produce a set of cast carbon-free bricks; thirdly, the production of cast carbon-free bricks basically needs to complete the molding process manually, the level of automation is low, and the labor intensity of workers is very high

However, there are essential differences in the material design and microstructure of the materials prepared by casting molding and machine pressing molding, resulting in a large difference in the microscopic pore size distribution of carbon-free bricks, and the pore size distribution of casting-molded carbon-free bricks is concentrated in 2 Micron, while the pore size distribution of machine-pressed carbon-free bricks is concentrated at 5-10 microns, which is an order of magnitude higher than the pore size of cast-formed carbon-free bricks

The penetration depth of high-temperature slag in refractory materials is proportional to the square root of the pore diameter of the material. The pore size of machine-pressed carbon-free bricks is an order of magnitude higher than that of cast-formed carbon-free bricks, resulting in machine-pressed carbon-free bricks. During use, the penetration depth of high-temperature slag in machine-pressed carbon-free bricks is much deeper than that in cast-formed carbon-free bricks. The significant increase in the penetration depth of slag will make machine-pressed carbon-free bricks thicker The metamorphic layer has obvious peeling and damage in the middle and late stages of use, so that the service life of machine-pressed carbon-free bricks is not as good as that of cast carbon-free bricks, and the service life of machine-pressed carbon-free bricks is not as good as that of poured carbon-free bricks. It is ultra-low carbon steel The main reason for the refractory materials in the working layer of the refining ladle molten pool area is to use cast-formed carbon-free bricks instead of machine-pressed carbon-free bricks