Question

The forging of cast iron is not possible due to which property?

Answer 1

Cast iron has a carbon content of approximately 4.2 wt%, which is the solubility limit of carbon in iron. Consequently, cast iron, while resistant to wear, is quite brittle, and cannot be forged. You would have to reduce the carbon content to something around 2% or less, which means that then you have steel, which can be forged. How is the carbon content of cast iron reduced? By melting it and blowing oxygen through the liquid iron to remove carbon as CO and CO2.