The clogging of the Submerged Entry Nozzle (SEN) during
billet continuous casting of mid-carbon steel is studied.
Clogging materials and inclusions in steel samples taken at
ladles, tundish and billets are investigated. The total oxygen on
the whole section of the billet is measured. Steel cleanliness at
unsteady casting states, including cast start, ladle change, SEN
change, cast end, and the special unsteady pouring period
induced by SEN clogging, are studied. Fluid flow and inclusion
motion and entrapment to SEN surface are also simulated.