FoundryMan-Custom manufacturer of ductile and chrome white iron castings

Grey iron and ductile iron

1. What is gray iron:
Grey cast iron, or gray iron, whose microstructure is characterized by the presence of flake graphite in the ferrous matrix, it is named after the grey color of the fracture it forms. Moreover, Fracturing is why gray iron has low tensile and impact strength. However, it is still the most common cast iron and the most widely used cast material.
2. Gray iron Composition:
The existence of graphite flakes is due to the addition of silicon, which acts to stabilize carbon in the form of graphite. Grey cast iron contains a composition of 2.5 wt.% – 4.0 wt.% carbon and 1.0 wt.% – 3.0 wt.% silicon, and some additions of manganese ranging from 0.1% to 1.2%
3. Grey iron applications:
Gray iron is a common engineering material because of its relatively low cost and good machinability. It is widely used in applications: internal combustion engine cylinder blocks, gears, hydraulic components, valves, pumps, tractor parts, truck parts, manhole covers, flywheels, manifolds etc.

1. What is Ductile iron:
Ductile iron is an iron-carbon-silicon alloy, also known as spheroidal graphite cast iron. Due to its unique microstructure, it has good machinability, plasticity, toughness, and higher strength comparing to carbon steel.
2. Ductile iron Composition:
Ductile iron is often made from scrap, pig iron and recycled ductile iron, contains 3.2 wt.% – 3.6 wt.% carbon, 2.2 wt.% – 2.8 wt.% silicon and 0.1 wt.% – 0.2 wt.% manganese, as well as smaller amounts of magnesium, phosphorus, sulfur and copper. The corrosion resistance of ductile iron can be improved if we adding chromium and nickel. Moreover, to reach better oxidation protection, Aluminum can be added replacing Silicon.
3. Ductile iron Applications:
Ductile iron material not only possesses comparable properties but also has competitive price than steel. Because it is more ductile than gray or white cast iron, it is ideal for a variety of engineering applications. For example, pipes for water and sewage infrastructure, vehicle gears and suspension components, brakes and valves, pumps and hydraulic parts, and housings for wind turbines etc.