ABSTRACT
Physical methods of refining are used for two purposes: refining raw steel to prepare speciality alloys of certain ranges of physical and mechanical properties and increasing the purity of certain metals used for special purposes. Electron beam refining process is used for refining steel as well as other metals. It utilizes a cascading action of molten metal in a vacuum. In case of steel the metal is melted in an induction heated crucible inside a vacuum chamber. In case of refining a refractory metal like molybdenum by this method, the heat generated by electron bombardment is enough to melt the metal and volatilize the impurities. Electric Arc Melting technique is particularly important for reactive metals with high melting points, example titanium, tantalum, zirconium, molybdenum, and special alloy steels. The process is conducted under high vacuum or in an inert gas atmosphere.
