In-depth study of mold heat transfer for the high speed continuous casting process

Mold heat transfer during the commercial high speed continuous casting up to 7 m/min was investigated in order to clarify the influence of various operating conditions such as casting speed, mold flux, mold thickness, thickness and height of mold coated layer and so on. A simple, but practical formula of heat flux has been derived in terms of those operating conditions by analyzing the heat flux data obtained in CEM® (Compact Endless Casting and Rolling Mill) caster based on simplified one dimensional heat transfer model. Especially, impact of mold parameters such as mold thickness, mold coated layer thickness and its height on the heat flux can be linearly expressed in the empirical formula derived. Heat flux ratio (HR), the ratio of the narrow face heat flux to the wide face one, is one of the important indicators to evaluate whether the solidified shell is evenly robust or not. Averaged HR in CEM® caster is around 0.87, which varies according to the caster specifications and operating conditions. It is suggested that the mold taper should be adjusted to maintain the HR as close to 0.87 as possible.