The electromagnetic cold crucible as a tool for melt preparation and continuous casting

Abstract

Electromagnetic cold crucibles (EMCC) are now standard equipment in material science laboratories and are gradually coming into use in two types of industrial applications, i.e. as batch crucibles for melt preparation and as bottomless cylindrical ingot moulds for continuous casting. The principal advantage is the absence of contamination. For this reason, they are at present mainly used in the preparation of strictly controlled refractory alloys, typically titanium based alloys. However, in light of increasingly stringent quality requirements, their use may soon be extended to a wider range of alloys. In melt preparation, the advantage of EMCCs with respect to other cold hearth furnaces is a much more uniform heating of the charge, resulting in a more uniform alloy composition and lower evaporation losses. With respect to coreless induction hot crucibles, another advantage is faster tap to tap cycles. EMCCs also offer a number of benefits for alloy remelting and shaping in continuous casting processes. In addition to the absence of contamination, EMCCs offer advantages related to the electromagnetic forces that can be used to reduce friction effects in the moulding system, improve surface structure and create liquid flow conditions that can control the grain structure and accelerate online chemical treatment. EMCCs can therefore raise quality and production rates in mass production processes.