As cast CC slabs of microalloyed steels are prone to surface cracking.
Precipitation phenomena, initiated during solidification, reduce ductility at
high temperature. The size, morphology and distribution of precipitates in as
cast semis depend on solidification rate, on secondary cooling, straightening
and cooling off the caster. Microsegregation of the microalloying additions
to the interdendritic boundaries during solidification increases precipitation
temperature. Results are presented concerning the effect of solidification
and cooling on precipitates characteristics in semis. The characterization
of precipitates is quite satisfactory although it could not be clearly correlated
with surface quality.