On the Behavior of Active Elements during Electroslag Remelting Process of Ni-base Alloy

Abstract

Behavior of such active elements as magnesium, aluminum and silicon during electroslag remelting process of a nickel-base alloy has been studied in a small scale ESR unit.
CaF₂-base Mg⁺⁺ bearing slags of two or three components; CaF₂-MgO, CaF₂-MgF₂, CaF₂-MgO-Al₂O₃, CaF₂-MgF₂-Al₂O₃, CaF₂-MgO-AlF₃, CaF₂-MgO-CaO were compared with conventional CaF₂ monoand CaF₂-Al₂O₃ binary slags.
Several hundred ppm of magnesium was found in the ESR ingots remelted under slags containing suitable amount of Mg⁺⁺ and low CaO and Al₂O₃, although none of magnesium but aluminum or silicon was added to the original electrodes.
It was shown that the distribution ratio of magnesium between slag and metal was related to the concentration of Al⁺⁺⁺ in the slag, oxygen and aluminum in the metal.