Vacuum Degassing of Steel
. This paper offers a brief review of current literature pertaining to vacuum degassing or vacuum casting of steel as practised in the U.S.A., Germany and the U.S.S.R. The advantages of vacuum degassing of large forging ingots, heavy section castings, for the conversion of rimming bessemer steels to killed steel and for the production of transformer steels are discussed. Operating pressures, reductions in gas contents and improvements in hydrogen segregation, steel cleanliness and mechanical properties, obtained with the various techniques, are described. The paper includes a description of an experimental vacuum streamdroplet degassing unit and some preliminary results obtained at the Physical Metallurgy Division Research Laboratories, Department of Mines and Technical Surveys, Ottawa, on laboratory steel melts. Experimental 500 lb direct arc, basic melts have been spray cast into either ingot moulds or dry sand moulds, held inside a vacuum tank. Also, 500 lb melts have been ladle degassed, or spray cast, into a ladle held inside the tank, and subsequently cast in air. Operating pressures of 3-10 mm Hg were used for the tests reported.
carbon steel, degassing, ingots, Ladle Vacuum, Casting, Castings, Degassing, Ingots, metals, Reduction, steel, Steels