Electroslag Remelting of Manganese

Abstract

The achievable level of service characteristics of manganese-based microalloyed steels is determined mainly by their purity. The Mr-O brand of electrolytic manganese that is used for these alloys requires additional refining due to its high content of sulfur and dissolved gases. Additional refining is usually performed by radiofrequency induction (RFI) melting under a slag layer. In order to use this method, special melting techniques had to be developed because of some anomalies of the refining process. For example, exceptionally severe conditions require the use of special, high-quality refractories, for the furnace and the crucible linings. Relatively low slag temperature reduces slag reactivity and necessitates refining times of six to eight hours, during which time repeated adjustments of the slag composition are required, along with running-off of the slag. All these requirements make the process cumbersome and lead to significant losses of manganese [1, 2].