Last month, we began a discussion on mold flux related defects by focusing on the surface defects of longitudinal face cracks. This month, we will discuss the surface defects of star cracks, oscillation marks and transverse corner cracks, surface inclusions and the carburiza-tion of the strand surface. Star cracks - Star cracks have been associated with the presence of copper in the surface of the strand. They usually are generated in the lower half of the mold, where the copper is scraped from the mold plates by the descending solid shell. The cause of star cracks lies in the phenomenon called hot shortness.
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