Ductile iron is a high-strength cast iron material developed in the 1950s. Its comprehensive performance is close to that of steel. Based on its excellent performance, it has been successfully used to cast some complex forces, strength, toughness, wear resistance. Parts with high performance requirements. Ductile iron has rapidly developed into a widely used cast iron material, second only to gray cast iron. The so-called "replacing steel with iron" mainly refers to ductile iron.
Ductile iron is obtained by spheroidization and inoculation treatment to obtain spheroidal graphite, which effectively improves the mechanical properties of cast iron, especially the plasticity and toughness, so as to obtain higher strength than carbon steel.
Cast iron is an iron-carbon alloy with a carbon content of more than 2.11%. It is obtained from industrial pig iron, scrap steel and other steel and its alloy materials through high temperature melting and casting. In addition to Fe, it also contains carbon in other cast irons in the form of graphite. If the precipitated graphite is in the form of flakes, the cast iron is called gray cast iron or gray cast iron, the cast iron when it is vermicular is called vermicular graphite iron, the cast iron when it is flocculent is called malleable cast iron or yard iron, and the cast iron when it is spherical is called It is called ductile iron.
The chemical composition of ductile iron except iron is usually: carbon content of 3.0 to 4.0%, silicon content of 1.8 to 3.2%, manganese, phosphorus and sulfur total not more than 3.0% and an appropriate amount of rare earth, magnesium and other spheroidizing elements.
Ductile iron castings are used in almost all major industrial sectors that require high strength, plasticity, toughness, wear resistance, resistance to severe thermal and mechanical shock, resistance to high or low temperatures, corrosion resistance, and dimensional stability. To meet these variations in service conditions, ductile iron is available in many grades, offering a wide range of mechanical and physical properties. It is pearlitic ductile iron with medium and high strength, medium toughness and plasticity, high comprehensive performance, good wear resistance and vibration damping, and good casting process performance. Its properties can be changed by various heat treatments. Mainly used for various power machinery crankshafts, camshafts, connecting shafts, connecting rods, gears, clutch plates, hydraulic cylinders and other parts.
