Electroslag remelting steel - to obtain low sulphur content

摘要

Process involves addn. of rare earths, pref. misch metal, to the consumable electrode in at lest the stoichiometric amt. to combine all the S in the electrode as sulphides, and using a slag of CaF2, Al2O3 and/or MgO without addn. of CaO and SiO2. Pref. the electrode is produced from a melt, contg. is not 0.024% S, which is vacuum degassed, strongly deoxidised and alloyed with the rare earths under vacuum. Remelting is carried out in a neutral or reducing atmos., pref. inert gas atmos. The prodt. has a sulphur content of 0.004%.