China OEM custom ductile iron lost wax investment casting products with CNC machining, heat treatment and surface treatment services.
Usually cast by investment casting, green sand casting and shell mold casting, ductile iron castings offer design flexibility and reduced manufacturing costs versus welded fabrications and forgings. Ductile iron castings have many characteristics, however, are not always the most cost-effective alternative to other ferrous alloys. Additionally, ductile irons are widely used in numerous manufacturing industries, including agriculture, automotive, hydaulics, rail trains, commercial trucks and aerospace industries.
Cast iron, mainly including the gray cast iron and ductile (nodular) cast iron are mainly used for casting by processes of sand casting, shell moulding casting, coated sand casting or lost foam casting. However, for some special situation, the lost wax investment casting process is also used due to their fine surface and higher accuracy. At RMC, we also have tha ability of casting gray iron and ductile with precision lost wax investment casting using silica sol and water glass for shell building. 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).
When 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 components 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.
