The use of oxygen activity measurement to determine optimal properties of ductile iron during production

Oxygen activity in ductile cast iron melts with ferritic and pearlitic structure has been measured as a function of the time while keeping the furnace temperature approximately constant around 1420ºC. A commercially available sensor, improved very recently, has been employed. The measurements are done in a 250 kg capacity induction furnace representing industrial circumstances. In ductile iron, oxygen activity measurement permits to determine the optimal melt condition. Castings poured in these circumstances present maximal nodularity, elongation and ferrite content combined with lowest hardness.