Development of an Infrared Laser-Based Apparatus for Investigating the Heat Transfer Characteristics of Mold Slag

The heat transfer performance of mold slag significantly affects strand quality and the continuous casting process, especially near the meniscus. To investigate the underlying heat transfer mechanisms, an infrared laser-based heat transfer simulation setup (IR-LHTS) was developed and validated through high-temperature experiments. Structural difference analysis was employed to accurately distinguish the thicknesses of solid and liquid slag films, thus improving calculation accuracy. The IR-LHTS achieved shell surface temperature of 1723–1773 K or higher and steady-state heat flux exceeding 2.0 MW/m², both significantly higher than previously reported values, which were below 1673 K and 1 MW/m². Using mold slags with basicities of 1.25 and 1.75, the calculated interfacial thermal resistances between the solid film and copper plate were below 4 × 10⁻⁴ m² K/W, accounting for only 27 to 38 pct of the total thermal resistances between the shell and the copper plate, significantly lower than the 40 to 80 pct reported by conventional methods. These results closely matched findings from industrial trials. The similarity in interfacial thermal resistance suggests comparable cooling rates of the slag film, with the resulting slag film structure closely resembling that of slag films extracted from the mold. Thus, IR-LHTS successfully replicates key thermal conditions in the meniscus region, including shell surface temperature, heat flux, slag film thickness, and interfacial thermal resistance, and provides an accurate evaluation of the heat transfer characteristics of mold slag.