High-speed continuous casting is prerequisite to realize the hot direct rolling. It is necessary to understand the phenomena of solidification and lubrication in the mold for the prevention of the troubles on the operation of high-speed casting.
In this work, the effects of mold oscillation curves on the heat transfer rate and lubrication behaviour in the mold are investigated by means of the measurement of temperature in the copper plate of mold, and hydraulic pressure of the cylinder for oscillating the mold, and the behaviour of lubrication in the mold at high-speed casting are discussed. The results obtained are as follows:
(1) The heat transfer rate near the meniscus for the non-sinusoidal oscillation curve is reduced approximately 10% in comparion with that for the conventional sinusoidal oscillation curve.
(2) The frictional force in the mold is proportional to the relative velocity of mold to casting speed, and the non-sinusoidal oscillation curve can reduce the frictional force drastically.
(3) The lubrication mechanism in mold at high-speed casting can be assumed to be liquid lubrication for the reason that the measured frictional force has a good agreement with the values calculated from the liquid lubrication model.
(4) The upper limit of casting speed in the continuous casting process with oscillating mold can be predicted to be 5 to 8 m/min on the basis of the comparison of the frictional force and the tensile strength of solidified shell beneath the meniscus.
