MgO-Cr7C3 brick for ladle slag line and production method of MgO-Cr7C3 brick

Abstract

The invention relates to a MgO-Cr7C3 brick for a ladle slag line and a production method of the MgO-Cr7C3 brick. According to the technical scheme, the production method includes: using 55-65wt% of high-purity magnesia particles as the aggregate and 15-25wt% of fused magnesia fine powder, 10-15wt% of Cr7C3 fine powder and 5-10wt% of SiC fine powder as the matrix materials; according to the contents of the aggregate and the matrix materials, evenly mixing the matrix materials first, adding the evenly-mixed matrix materials into the aggregate, and evenly mixing; adding alumina sol accounting for 3-7wt% of the sum of the aggregate and the matrix materials, mixing for 5-10 minutes, and using a semi-dry method to perform mechanical pressing; placing the formed blank into a high-temperature furnace, sintering at 1500-1600 DEG C and under the argon atmosphere, and keeping the temperature for 2-3 hours to obtain the MgO-Cr7C3 brick for the ladle slag line. The production method has the advantages that the method is simple in process, and the produced MgO-Cr7C3 brick is high in compactness, large in high-temperature bending strength, high in slag erosion resistance and low in pollution to molten steel.

Description

technical field [0001] The invention belongs to the technical field of refractory materials for ladle slag lines. Specifically relate to a kind of MgO-Cr for ladle slag line 7 C 3 Bricks and methods of making them. Background technique [0002] Ladles are important storage, transportation and smelting equipment in the steel industry. The refractory material at the ladle slag line is subjected to the erosion and flow of steel slag and molten steel during the steelmaking process, resulting in structural spalling and slag erosion. Therefore, the ladle slag line generally requires service refractories to have good thermal shock stability, slag erosion resistance and erosion resistance. [0003] At present, the refractories for ladle slag line generally adopt magnesia-calcium refractories and magnesia-carbon refractories. [0004] Magnesium-calcium refractories are used as refractory materials for ladle slag lines. Although they have good high-temperature mechanical properti...

AI Technical Summary

Problems solved by technology

[0004] Magnesium-calcium refractories are used as refractory materials for ladle slag lines. Although they have good high-temperature mechanical properties, excellent corrosion resistance to molten steel and steel slag, good thermal shock stability, and especially the characteristics of purifying molten steel, magnesia-calcium refractories In the process of preparation and use, it is easy to absorb moisture in the external environment and be pulverized and damaged, which greatly reduces the life of magnesium-calcium refractory materials, thereby restricting the turnover and use of ladles.

[0005] Magnesia-carbon refractories are used as refractory materials for ladle slag lines. Although they can meet the service life requirements, the biggest problem is the carbon increase in the subsequent ladle refining process.

At the beginning of production, most steel types have a relatively high frequency of carbon exceeding the standard, which reduces the quality of the steel

In addition, due to the oxidation of carbon, magnesia-carbon refractories form a decarburization layer, which accelerates the erosion of slag liquid on refractories and restricts the use of magnesia-carbon refractories.