Features and Restrictions of Electroslag Remelting with Silica‐Bearing Slags for Lightweight High Manganese Steel

Abstract

Experiments are conducted to investigate the electroslag remelting process of Fe‐(20‐30)Mn‐(10‐12.0)Al‐(1‐2)C (wt%) steel in a short collar mold using a characteristic silica‐bearing slag to improve nonmetallic inclusion morphology. The effect of the “one‐slag melt” with silica on the changes in the chemical composition of the ESR ingot along its height is studied. The observed silicon pick‐up in metal at ESR is caused by the interaction of silica‐bearing slag with aluminum from metal composition (10%), stipulated by the ESR process nature and cannot be avoided. CALPHAD prediction of phase formation at observed changes of metal chemistry is proved by microstructure and EDS investigations of as‐cast metal of remelted ingot. Silicon pick‐up in obtained limits does not change the morphology of the main phases in the remelted Fe–Mn–Al–Cr‐C‐(Si) steel, but the microhardness of the phases becomes higher. Due to the low speed of remelting provided by ESR TC, the as‐cast metal structure and nonmetallic inclusions are refined. Experiments show that high silica‐bearing slag is not convenient for remelting high aluminum steels because of silicon transfer into ESR ingot at slag's silica reduction by aluminum.