to a casting orifice 15 a mold b is applied to the casting orifice by a pressure plate p activated by a jack not shown the interior 8 of the furnace is placed under pressure through a duct 5 from an inert gas source such as argon or nitrogen to displace the liquid metal alloy to the casting orifice without risk of oxidizing the molten alloy upon contact with the gas the drain 10 and channel 13 are heated and to this end a copper induction coil 17 is embedded inside the refractory lining 12 coaxially with the x x axis and follows the bent outline of the channel 13 along almost its entire length as is known the hollow induction coil 17 is internally cooled by water which eliminates all expansion problems with encasing the coil within the refractory lining 12 the ends of the coil are connected to two terminals 18 of an aperiodic electric current generator 19 in a conventional manner induction heating of the liquid metal alloy is obtained when the alloy completely fills the channel 13 and the coil 17 is fed with electric current the primary is the coil 17 and the secondary is the molten metal alloy according to the invention with regard to heating the channel 13 even in the absence of liquid metal inside the channel a graphite sleeve 20.