Fining cast iron by stirring (chaolian)
Afinado del hierro colado por agitación (chaolian)
- Date
- c. 100 BCE · confidence medium
- Place
- Tieshenggou, Gongyi, Henan, China
- Credited to
- State ironworks of the Han dynasty
- Field
- Matter & energy
What it is
Cast iron was melted and stirred in the open air in open hearths to burn off some of the carbon and obtain wrought iron or steel. It is the functional equivalent of European puddling, almost two thousand years earlier.
Henry Cort's puddling process (1784) was developed independently.
What it led to
- cheap steel and wrought iron from cast iron
- steel weapons and tools of Han China