Cold model experiment on infiltration of mould flux in continuous casting of steel: Simple analysis neglecting mould oscillation

A new cold model of continuous casting is developed to clarify the infiltration of mould flux into channel between a mould and a solidifying shell. In the experiment, silicone oil is poured and infiltrated down into the channel between an acrylic plate and a moving belt. In contrast with most of the previous analyses that assumed a fixed thickness of the liquid flux film, this model is based on an idea that the thickness can be varied depending on the balance of forces acting on the shell: static pressure in the molten steel pool, and dynamic and static pressure in the mould flux channel. Furthermore, a linear gauge sensor that is in contact with the acrylic plate monitors the film thickness of oil, while in continuous casting the thickness of mould flux cannot be measured during the operation. Simple experiments without oscillating motion clearly reveal that the infiltration behavior is largely dependent on the profile of channel: In the channel that becomes narrower in downward direction, the infiltration of oil is enhanced with the increase of both belt velocity and oil viscosity. In contrast, for the channel that becomes wider along the downward direction, the increase of the velocity and the viscosity reduces the oil infiltration. In continuous casting operation, the increase of both casting velocity and viscosity of mould flux decreases the mould flux consumption. Those observations indicate that the infiltration of mould flux is strongly governed by the channel that becomes wider in casting direction.