Refractory lining of induction holding furnaces for the foundry

In the foundry industry, the development of melting equipment - long campaign cupola furnaces and medium-frequency induction furnaces - has forced founders to install holding furnaces to regulate production, promote liquid metal homogeneity and stabilize temperature. Increasing demand and the automation of casting processes led to a rapid increase in holding furnace capacity, from 50 tons of cast iron yesterday to over 100 tons today. Induction furnaces with holding channels are definitely the best adapted to this function and evolution.

Particularly in cast iron foundries, this development has brought to light a number of problems with refractory linings. The fact is that the vessel and inductor are subject to considerable metallostatic pressure, which can lead to damage or infiltration, even to the point of piercing the refractory lining and bringing the furnace to a halt.

Faced with this worrying situation, particularly for holding furnaces, furnace builders, refractory material manufacturers and foundrymen joined forces to design and develop more reliable, higher-performance linings. These joint efforts rapidly doubled the service life of furnaces and their inductors.

This article describes these new designs which take into account new metal alloys, the necessary increase in furnace capacity and higher electrical power for inductors.