Inoculation of molten cast iron using magnesium wire - provided with protective coating, is carried out in pressurised furnace

A dosed amt. of Mg wire is added via an air lock in the furnace roof and travels downwards into the melt; and the wire has a protective sheath retarding the evapn. of the Mg before it enters the melt. The rate of feed of the Mg wire into the melt is pref. determined empirically, or by measuring the oxygen content of the melt. The pref. furnace has a gas-tight roof contg. a tube via which Mg wire is added to the melt from a spool and wire feeder located above the furnace. An exact amt. of Mg can be added to the melt, esp. for mfg. nodular cast iron.