Oscillation and Surface Mark Patterns in Slab Casting

摘要

Transverse surface cracks are caused by stresses and strains during casting and occur mostly in oscillation marks. Classical theory relates the depth of marks to the negative strip time and predicts the pitch of marks as given by the mould cycle. Measurement of mark spacing and depth under thick slab casting conditions at low casting speeds offers a chance to extend the knowledge into previously unexplored ranges. A large data set of profilometer sections from various casting parameters and some very long samples have been analyzed with respect to mark pitch and depth. The results are contrasted with the classical theory of oscillation marks. Some conclusions on the mechanism of mark formation are drawn.