Thoughts about the initial solidificatio

The initial solidification process in continuous casting is critical for the surface quality of the strand, particularly concerning oscillation marks formed by mould oscillation. This study distinguishes between folding marks and overflow marks, analyzing the main parameters influencing their formation through theoretical and metallographic analysis. The research presents an examination of the effects of casting speed and oscillation frequency on oscillation mark formation. It is demonstrated that a meniscus forms at the top of the growing shell, with its maximum height determining the ideal distances between marks, which are tied to the mould frequency. Deviations from this ideal frequency lead to the emergence of overflow marks and folded marks, often resulting in macrosegregation and cracks, thereby varying the distances between marks. The depth of these marks is calculated based on heat flow and surface tension balance, revealing a decrease in mark depth correlated with increased superheat and decreased surface tension of the meniscus. The study also discusses crack formation in folded marks and segregation associated with both mark types, offering insights into the underlying mechanisms of defect formation in continuously cast materials.