In the production of specialty steels, a number of merallurgical problems are encountered that affect the ultimate quality and cost. To name a few, there are high-cost charging materials, long melting times, inadequate alloy recovery, the need for compliance with extremely close compositional analysis, costly desulfurization, slow precipitation of deoxidizing products, high hydrogen contents, oxygen, nitrogen, and hydrogen pick-up during tapping, and segregation during solidification. Various degassing methods developed, with and without agitation, washed and non-washed baths, are all applied in vacuum decarburizing, deoxidizing, and complemental alloying. It is possible to keep these operations separate from the actual melting plant and adopt a two-stage technique made up of the “melting furnace” and “plant for treatment.” This separation increases capacity substantially and reduces costs. Larger, economical vacuum-induction furnaces permit melting, decarburizing, deoxidizing, alloying, evaporation, and pouring under vacuum or inert gas. Two remelting practices using vacuum and slag have been developed to very high technological standards which permit the application of additional refining and ensure a practically segregation-free solidification.

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