Influence of trace Sb addition in ductile cast iron

Abstract

Since the ductile cast iron has the characteristics, such as outstanding mechanical properties, it is broadly used for auto parts, machine structure parts and so on. RE elements are added as spheroidizing treatment. However, it is reported that it promotes growth of the chunkey graphite. Antimony is added as a purpose to prevent formation of the chunkey graphite. In this study, the influence of antimony to mechanical property and graphite formation on ductile cast iron is researched by changing quantity of antimony addition. In a scanning electron microscope (SEM) observation, the surface form of the spheroidal graphite was obtained the coarse surface in basic alloy, while the smooth surface was obtained in 0.097Sb. In transmission electron microscope (TEM) observation, internal structure was observed the shape of a block with the spheroidal graphite of the basic alloy, while the internal structure was observed smoother with the spheroidal graphite in 0.097Sb.