Malleable cast iron is produced

A. By adding magnesium to molten cast iron

B. By quick cooling of molten cast iron

C. From white cast iron by annealing process

D. None of these

Answer: Option C

Solution(By Examveda Team)

Malleable iron is obtained by the heat treatment of white iron so the hard iron carbide structure of ledeburite is converted to a matrix of ferrite or pearlite and graphite is precipitated within the iron.
This form of graphite is sometimes referred to as tempered carbon.