Effect of Slag Channel Longitudinal Pressure Distribution on Oscillation Mark Formation and Lubrication in Continuous Casting

As a link between mold oscillation and the slab shell mechanical response, slag channel pressure directly influences shell morphology and slag film lubrication. This study investigates longitudinal pressure distribution in the slag channel by developing a coupled model that incorporates multiphase flow, heat transfer, and solidification. The study reveals a functional zoning of pressure between the meniscus and submeniscus region and analyzes how pressure variations influence oscillation mark depth and slag channel lubrication under different mold oscillation parameters. Results show that meniscus pressure governs mark formation: larger pressure fluctuations deepening the marks. Conversely, submeniscus pressure regulates channel lubrication: higher pressure maintains wider channels and enhances lubrication. Parametric analysis indicates that lower amplitude or higher frequency reduces meniscus pressure fluctuations and deepens marks. However, the same parameter changes also decrease submeniscus pressure, producing narrower channels and decreased lubrication. Implementing nonsinusoidal waveforms achieves synergistic optimization by simultaneously reducing meniscus pressure differentials and raising pressure below the meniscus, which diminishes mark depth and improves lubrication. These insights elucidate the longitudinal pressure mechanisms in slag channel and provide theoretical guidance for optimizing continuous casting parameters.