Study on Wear Phenomena of Tundish Working Lining by Slags of Billet Caster

Total number of heats taken in tundish refractory working linings (MgO-based) varies with three steel grades produced in the Long Product Complex at Tata Steel. The duration of the sequence heats (of 60-70 min) for low-C, med-C and high-C steel grades made at billet caster are 14-16, 16-18 and 22-24 h respectively. These differences are due to different rates in erosion and corrosion of the three types of tundish slags arising in three different steel grades and different liquidus temperatures of three steel grades. The tundish slags have different chemical compositions, liquidus temperatures and viscosity. An attempt has been made in the present work to understand the wear mechanisms of MgO-based refractory linings by different tundish slags in the three steel grades. Chemical analysis, optical and scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) have been used to characterize the slag infiltrated MgO-based tundish lining samples collected from the plant. The present work has been undertaken to find out the wear mechanism by different tundish slags, take corrective measures with regard to slag chemistry and MgO lining material to minimize the erosion and corrosion, and enhance the continuous casting durations.