Possibility of Producing High Quality Cold Rolled Coils with Thin Slab Casting Production Route

Mold powder entrapment is much easier to occur in thin slab casting because the fluctuation of the liquid steel level and the velocity of the surface flow of the liquid steel in thin slab casting mold are larger than those in conventional slab casting owing to the higher casting speed and smaller volume of the mold in thin slab casting.The production in NUCOR, Thyssen-Krupp, etc. indicates that the surface quality of the cold rolled coils produced with thin slab casting route is still lower than that produced with conventional route.In order to produce higher quality cold rolled products, thickness of the slab should be relatively increased to decrease the casting speed and enhance the cushion function of the mold to the steel flow.It is recommended by the author to use 120 mm thick mold and casting speed of 3 m/min.In addition, for reducing mold powder entrapment, systematic investigations should be done on the liquid steel flow control in the mold of the middle thickness thin slab caster, such as the structure of the SEN, the immersion depth of the SEN, the optimized casting speed, EMBr, mold powders, etc..