Born in henan ligou iron ditch of iron smelting sites of the late in the western han dynasty, unearthed in iron ?, through metallographic examination, has a radial spherical graphite, spheroidization rate is equal to the modern standard level. The modern nodular cast iron is developed as late as 1947. Ancient Chinese cast iron, silicon content in a fairly long period of time are low, in the western han dynasty about 2000 years ago, the spheroidal graphite iron, China has low silicon pig iron castings by diffusion annealing method. This is the major achievement of ancient Chinese cast iron technology, is also a miracle in the history of world metallurgy.
Nodular cast iron with its excellent performance, in use can replace expensive sometimes cast steel and forging steel, widely used in mechanical manufacturing industry. International metallurgy line