Abstract: Up to now, most factories still use traditional risering methods to produce ductile iron castings,resulting in high production cost and that it could not prevent castings from secondary shrinkage defects.
This paper expounds shrinkage characteristics of ductile iron in the course of cooling and solidification,and illustrates how pressure control risering principle is applied to the technology design of ductile iron castings. Using new risering technique can prevent castings from solidification defects and notably increase pattern yield.