Interaction of Molten Ultra-low Carbon Steel with Carbide and Nitride Refractory Materials
Nozzle clogging of tundish and submerged entry nozzles causes low productivity and inferior quality during continuous casting of aluminum-killed steels. Clogging is caused by an accretion layer that forms on the inside surface of the nozzle orifice restricting flow of the liquid steel. The current generation of refractory materials is known to react with molten steel forming products in the nozzle orifice that can increase the clogging process. Nozzle materials that are either inert with liquid steel or prevent the attachment of inclusions decrease clogging. In the present investigation, molten steels containing different levels of aluminum were placed in contact with boron nitride, silicon carbide, and boron carbide to evaluate these materials as potential nozzle refractories. The contact surfaces between the refractory and steel were examined using reflected light, cathodoluminescence, and scanning electron microscopy. All three materials reacted with molten steel. Both boron nitride and boron carbide reacted with molten steel to form metallic iron and iron boride. On the other hand, the silicon carbide reacted with molten steel to form iron and iron silicide. Silicon carbide and boron carbide reacted more extensively with molten steel thatn boron nitride.
R. B. Tuttle et al., "Interaction of Molten Ultra-low Carbon Steel with Carbide and Nitride Refractory Materials," Refractories Applications Transactions, American Ceramic Society, Jan 2007.
Materials Science and Engineering
American Iron and Steel Institute
United States. Department of Energy
Keywords and Phrases
Aluminum-Killed Steels; Clogging; Submerged Entry Nozzles; Tundish Entry Nozzles
Article - Journal
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