Solidification Behavior of Water-Cooled and Subzero-Chilled Cast Iron on Mechanical Properties

摘要

Hypoeutectic cast iron specimens cast using chills that are water-cooled and liquid-nitrogen-cooled (subzero chilling) were compared with specimens of the same chemical composition, which were sand-cast without any chill. The solidification behavior, number of eutectic cells, grain size, and effects of these on the mechanical properties such as strength and fracture toughness were recorded and analyzed in this paper.It is revealed from the above investigation that subzero and water-cooled chilled cast irons exhibit severe under cooling as compared to that of normal sand-cast iron. Thus, it is concluded from the investigation that nucleation conditions are completely altered during solidification, which is considered to be responsible for the variation in eutectic cell size, grain size, microstructure, and hence mechanical properties of the cast iron.