Recent Trend on Tundish Design

Abstract

Approximately 90 % of world’s crude steel production is casted using a continuous casting process where the liquid steel flows from ladle to tundish next to mold in a continuous casting system. In modern steelmaking and continuous casting plants, tundish technology from both fundamental and practical point of view is most important. Steel is produced in three basic route like, basic oxygen furnace (BOF), electric arc furnace (EAF) & induction furnace (IF). BOF hot metal and scrap are blown by oxygen gas with a flux addition such as lime etc. A modern EAF produces steel by remelting and refining steel from DRI, scrap and other raw materials, and also uses oxygen gas injection and lime addition. In induction furnace main input raw materials are DRI & scrap.The steel melt with dissolved oxygen thus produced is tapped into a ladle, where it is deoxidized with ferroalloys, Fe-Si, Fe-Si-Mn, and/or metallic aluminum. The deoxidation products,such as silica, manganosilicates, alumina, aluminosilicates, aluminates and/or their composites, are largely removed from the melt by flotation.Whenever necessary, the deoxidized melt is further processed in a ladle furnace (LF) to remove any remaining suspended oxide particles (called non-metallic inclusions, or simply inclusions), to lower the sulfur content, and to adjust the melt’s chemistry and temperature. Degassing of steel melt is done in vacuum refining facilities (RH, VAD, or VOD) to decrease hydrogen for crack sensitive grades and/or carbon for ultra low carbon grades. The melt is then transferred from the ladle via a tundish into the mold of a continuous casting machine and is solidified as slabs, blooms, or billets. In the last three decades, continuous casting has become a mature technology for the solidification of steel. Continuous casting offers many advantages including better premium cast-metal yield chemical homogeneity, and better inclusion cleanliness. In continuous casting process, the tundish plays an important role in linking the ladle with the continuous casting machine. Tundish technology as an important component of the steel production processes, with emphasis placed on the metallurgical aspects of producing clean steel.