This is a great achievement in the ancient casting iron techniques in our country, and is also a miracle in the history of international metallurgy development. As nodular cast irons have many excellent properties, they can be substitutes for expensive cast steel and forged steel in use. Thus they’re widely adopted in machine manufacturing industry. Once upon a time, all the International metallurgical organizations mostly believed nodular cast iron was invented by an Englishman in 1947.
Within a rather long period, the Si contents are all lower among the disclosed ancient iron castings. That’s to say that those globular graphite of Chinese ironwares could be achieved by dithering and annealing treatments through low-Si pig iron castings during Western Han Dynasty..
Some western scholars even alleged it’s unimaginable to create nodular cast iron without modern techniques. But when Chinese professionals adopted related modern technological means to further study the 513 unearthed ironwares in Han and Wei Dynasties in 1981, they concluded nodular cast iron had been existed in the Han Dynasty by analyzing plenty of data. Related essays with the discovery were read out in The 18-session World Conference on History of Science, which shocks the international casting field and the history of science field.
The rule of how to create nodular cast iron by dithering method has early been found among the ancient Chinese people. It means the part of international metallurgy history will be rewritten.