Cold Model Experiment on Infiltration of Mould Flux in Continuous Casting of Steel: Simulation of Mould Oscillation

Abstract

For mould flux infiltration in an oscillating mould, we develop a new cold model experiment in which silicone oil is infiltrated down between a moving belt and an acrylic plate. The apparatus is designed on the basis of the following concepts:(1) The film thickness of liquid flux channel is varied during mould oscillation with the balance between the pressure in the flux channel and static pressure in the molten steel pool.(2) The flux channel has a profile that it becomes wider along casting direction.For this purpose, the film thickness of the infiltrating oil, which can be changed by the oscillating motion of the belt, is directly measured employing a linear gauge sensor.The experiment reveals that the film thickness is increased during the upward motion of the belt and is decreased during the downward motion. Using the measured film thickness, a theoretical model calculates infiltration rate of the oil that corresponds to mould flux consumption in casting operation. It successfully reproduces the empirical observation that mould flux consumption decreases with increasing casting velocity, flux viscosity or oscillating frequency. Those results provide a new mechanism of mould flux infiltration, where the flux is infiltrated down from the last stage of positive strip time until the latter half of negative strip time. In this period, the downward motion of the mould and strand draws the flux down through the channel that has been widen by the preceding upward stroke of the mould.