9th ECCC European Continuous Casting Conference – ECCC 2017

Atypical secondary oscillation marks (SOM), and related transversal surface cracks, have been detected on the billet surface between two consecutive primary oscillation marks, when casting with abnormal oscillation settings in Curve Continuous Casting (CCC). The study of the obtained near surface solidification microstructure under this conditions have shown similarities with the microstructure obtained in the Horizontal Continuous Casting (HCC), where SOM were also frequently observed. The oscillation parameters and the corresponding shell formation of both casting processes have shown close similarities when in the CCC process the movement of the strand relative to the mould is considered. The study of solid shell formation under this perspective gives a new insight in the very beginning of solidification and on the formation oscillation marks mechanism. A study of the equivalence between the HCC extraction parameters and CCC oscillation parameters is carried out, in order to avoid SOM and the formation of hook segregated cracks.