16 - Characterization of Inclusions in Ductile Iron Castings

Abstract:

Many factors contribute to inclusion formation in cast metals, and this is particularly true in the production of ductile iron castings. The types of inclusions can range from oxides and sulfides to carbides and carbonitrides. Such inclusions can have a distinctly adverse effect on mechanical properties, and recent work sponsored by the DIS has shown that these inclusions can measurably reduce machinability. The incidence of inclusions is deceptive in some ways in that their damaging effects are not always readily seen in the standard tensile properties determined in the foundry; they show up in impact and fatigue properties.