GB1281985A - Process for the production of oriented silicon iron by vacuum degassing and continuous casting - Google Patents

Abstract

1281985 Making silicon-iron sheet; continuous casting ARMCO STEEL CORP 9 March 1970 [14 March 1969] 11196/70 Headings B3A and B3F In a process of making grain oriented siliconiron sheet, the charge is tapped from an open hearth furnace into a first ladle to which is added aluminium partially to kill the steel. The charge is teemed into a second ladle with most of the slag retained in the first ladle. The silicon is preferably placed in the bottom of the second ladle before the charge is added. The melt is transferred to a vacuum degassing unit where minor additions may be made to obtain the desired chemistry in the steel. The silicon may be added in a degasser. After degassing, the melt is continuously cast and protection from oxidation, at least between a tundish and the mould, is given by a protective submerged entry tube and a powder cover of inorganic silicate (which also minimizes pick-up of hydrogen from mould lubricant) on the metal in the mould. The melting of the powder promotes its action both as a flux and lubricant between the melt as it solidifies and the mould. The solidified metal slab is slowly cooled by water spraying at a rate sufficient only to prevent damage to the metal, which may be rolled with residual heat, descaled, decarbonized, cold rolled and then annealed. In an alternative method a charge is tapped from an electric furnace into a ladle containing at least a substantial part of the silicon, the slag being minimized by known procedures. A preferred analysis of the metal is 2À5-40% silicon, 0À027-0À040% carbon, 0À04- 0-08% manganese, 0À020-0À026% sulphur or selenium, <0À004% oxygen, balance iron and impurities.