What is Ductile Iron
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Nodular cast iron is a high-strength cast iron material developed in the 1950s. Its comprehensive properties are close to steel. Based on its excellent properties, it has been successfully used to cast some parts with complex stress and high requirements for strength, toughness and wear resistance. Nodular cast 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 nodular cast iron.
Nodular cast iron is spheroidized and inoculated to obtain spherical 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 carbon content greater than 2.11%. It is obtained by high-temperature melting and casting of industrial pig iron, scrap steel and other iron and its alloy materials. In addition to Fe, the carbon contained in other cast iron is precipitated in the form of graphite. If the precipitated graphite is in strip form, the cast iron is called gray cast iron or gray cast iron, the cast iron in worm form is called vermicular cast iron, and the cast iron in flocculent form is called malleable cast iron or code iron The cast iron when it is spherical is called nodular cast iron.
Except for iron, the chemical composition of nodular cast iron is usually: carbon content of 3.0 ~ 4.0%, silicon content of 1.8 ~ 3.2%, total amount of manganese, phosphorus and sulfur of no more than 3.0%, and an appropriate amount of nodular elements such as rare earth and magnesium.