Ductile Cast Iron Investment Casting

OEM custom ductile cast iron castings with investment casting process from China casting company. We can also provide services of CNC machining, assembly and surface treatment. 

Cast irons are the ferrous alloys which have carbon contents of more than 2%. Though cast irons can have a carbon percentage between 2 to 6.67, the practical limit is normally between 2 and 4%. These are important mainly because of their excellent casting qualities. The gray cast irons and ductile cast irons (also called nodular cast iron or spheroidal graphite iron) are the mostly used in casting foundry.

The ductile cast iron is a nodularized iron whose graphite is present as small, round, and well-distributed particles, its weakening effect is small and such cast irons would have higher ductility. This type of cast iron is called ductile or nodular iron or spheroidal graphite or simply SG iron. This form of graphite can be achieved by adding elemental magnesium or cerium or a combination of the two elements to molten cast iron. Magnesium is added in quantities of 0.07 to 0. 10% followed by the addition of ferro-silicon to promote graphitization. During solidification, magnesium helps in the distribution of graphite throughout the metal.

Ductile iron has better strength-to-weight ratio, better machinability and higher impact value. Moreove, the ductile iron castings are produced by casting process wherein better control of component shape can be achieved compared to drop forging. Thus, many a component such as crank shafts and connecting rods manufactured usually by drop forging is increasingly being replaced by ductile iron castings.