Development of nodular cast iron:
Cast iron was developed by the French in 1722. At that time, white heart malleable cast iron was developed. Later, black heart malleable cast iron was developed successively. Until 1947, an Englishman found that there was spheroidal graphite in a kind of cast iron, in fact, it was a kind of spheroidal graphite cast iron. Later, through continuous improvement, some rare earth magnesium were added to the cast iron to get the true meaning of ductile iron. Since then, it has also started large-scale production application, become a widely used cast iron material. We know that China is one of the first countries in the world to start metal smelting. Therefore, in some iron unearthed ancient smelting sites in China, a small amount of radial spheroidal graphite was found. According to textual research, these iron appeared in the Western Han Dynasty, more than 2000 years ago, which once again proves that ancient China has a very high smelting technology.
Features of nodular cast iron:
Nodular cast iron has the advantages of high strength, light weight, good toughness, impact resistance high low temperature resistance, so it is widely used in some key parts of machinery, such as crankshaft, valves pipes.