A formation mechanism of transverse cracks on CC slab surface.

Abstract

Transverse surface cracks were metallorgaphically investigated and the local segregation was found to be the origin of transverse surface cracks on continuously cast slabs. The positive segregation spreaded over an oscillation mark and showedhigh phosphorous content. At the same time, the sharp negative segregation was also seen adjacent to the positive segregation along the mark. This positive segregation penetrated deeply into austenite grain boundaries, through which transverse oracks propagated. Thefractured surface was smoothand the precipitates of MnS was found.