MOLTEN STEEL INTERACTIONS WITH TUNDISH LININGS AND REFRACTORY GLAZES
"In the final stages of casting, molten steel is in contact with two main types of refractories: the working lining of the tundish used to serve as an intermediate vessel between the ladle and copper mold, and the various glazed carbon-bearing refractories used to control the flow of steel from the ladle to the tundish and from the tundish to the mold. If steel interacts with these refractories in such a way as to result in the formation of inclusions, it may be too late to remove them, leading to degradation of the steel’s mechanical properties. Understanding these interactions and what variables affect them will be aid in determining what refractories to use for these applications, which will reduce the risk of excess inclusion formation and slow down corrosion of the refractories. In this work, different approaches were taken to better understand the interactions between refractories and steel. Through the use of rotating dip tests, it was determined that the formation of spinel accretion occurs when a magnesia-based tundish lining material is in contact with aluminum-killed steel. This formation is limited by the ability of magnesium to transport to the interaction interface, which typically occurs due to the exudation of a liquid secondary phase found in dead-burned magnesia aggregates. Through corrosion studies, it was determined that basic tundish cover fluxes target the silica-rich phases often found in these tundish linings (such as olivine). Experimental studies also determined that inclusions would accumulate on the surface of glazed carbon-bearing refractories, and that this build-up may be modified through the reduction of refractory components. There is a possibility that glaze may influence the accretion and transformation of this material"--Abstract, p. iv
Magnesia, Nozzle Clogging, SEN, Spinel, Steel-Refractory Interactions, Tundish, Materials Science and Engineering
Missouri University of Science and Technology
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