Continuous Casting of High-Al Steel in Shougang Jingtang Steel Works

Abstract

Reaction between mold flux and liquid high aluminum steel is considerably strong. It changes the physical property of the mold powder greatly and leads to a larger fluctuation of heat flux in the mold. Transverse depression and longitudinal cracks were often found on the slab surface. Three casting trials were carried out to investigate the effects of mold powder and slab width on castability and surface quality of high aluminum steels. The result shows that the SiO2 content of liquid mold powder decreases while Al2O3 content increases during the casting process. It was found that the degree of slag-metal reaction, addition and consumption of mold powder determined the final equilibrium content of SiO2 and Al2O3. Under the same process condition, it takes more time for the mold powder content to reach equilibrium when casting wide slabs than narrow ones. Considering the sticking and slab surface quality, mold powder A with high melting point and high viscosity is suitable for casting 1 200 mm-width slab and mold powder B with low melting point and low viscosity is suitable for casting 1 900 mm-width one.