Steuler-KCH GmbH (Höhr-Grenzhausen, Germany):

Schönwelski W., Mag. Min.

Ruwier K., Mag. Eng

Foellbach S., Mag. Eng

Sperber J., Mag. Eng., e-mail: m.merl@steuler.de

High-quality steel is characterized by absence of ceramic inclusions (so-called “clean steel”) that retard or hamper consequent ingot processing by rolling or forging. Recent developments of refractories already propose content of Al₂O₃ equals to 92 % as a standard, while materials with 99 b% content of Al₂O₃ are lo-cated on the threshold between laboratory level and commercial production. It is shown that corrosion susceptibility decreases with rise of alumina content level. Silica is the most weal ceramic component in refractory material that is used in bottom casting in ingots, and alumina content in it should be increased continuously up to maximum level. The authors displayed that complete wettability by steel melt can be achieved in the case when alumina-bearing material, containing nitrides, is used in corrosion resistance tests. Additionally, high-alumina materials practically are subjected to corrosion in rather less amount, comparing with the standard requirements. It is concluded that avoiding appearance of ceramic inclusions is espe-cially important for large ingots and, respectively, for more durable casting.

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