Based on the data of fluctuation of liquid level in mold and casting speed fluctuation during concasting process of billet of S20C medium carbon steel for 24 h

the curves of instantaneous position and fluctuation of liquid level in mold and the curves of fluctuation of casting speed have been plotted

and the thickness and shape of slag layer in mold are measured by a thin steel sheet. The effect of casting speed fluctuation on fluctuation of liquid level in mold is discussed. Results show that with increasing and decreasing casting speed the fluctuation of liquid level in mold becomes more violent

to a certain extent the casting speed fluctuation influences the fluctuation of liquid level in mold but not only one factor.