Cast iron is iron carbon alloy which carbon content is greater than 2%.Carbon exist in cast iron mostly as graphite morphology,sometimes as cementite. In addition to carbon,also contains 1%~3% of silicon in cast iron,and
manganese,phosphorus,sulfur and other elements..Cast iron could be divided into below:
1.Grey cast iron.High carbon content (2.7% ~ 4.0%),carbon mainly exist in flake graphite morphology,fracture grey.Low melting point (1145 ~1250 ℃),the shrinkage is small when solidification.Compressive strength and hardness is close to carbon steel,good shock absorption.Also the abrasion resistance is good because of flake praphite.Casting and machining performance is better.Used in the manufacture of machine tool bed, cylinder,enclosure structure, etc
2.White cast iron.Low content of carbon and silicon.Carbon mainly exist in cementite form, fracture in silver.The shrinkage is big when solidification,easy to produce shrinkage cavity and crack.High hardness, brittleness, unable to bear impact load.Mostly manufacture malleable iron blanks and wear resistance parts.
3.Malleable iron.Formed after annealing treatment of white cast iron,distribute as graphite flocculent,hereinafter referred to as ductile iron.For its uniform organizational performance, wear resistance,good plasticity and toughness.Used in the manufacture of complex shape parts, can withstand the strong dynamic load.
4.Nodular cast iron.The grey cast iron molten iron after spheroidizing treatment,precipitation of graphite spheres, hereinafter referred to as ductile iron.All or most of the carbon exist in free state of spheroidal graphite, fracture into silver.Than ordinary grey cast iron has high strength, good toughness and plasticity.
So what are the differences between cast steel and cast iron?
Properties:Cast steel is cast iron with carbon elements added.Cast steel is better to shape and less frangible .Also we could add some other elements into cast steel,such as chromium,which could make stainless steel.Cast iron is not easy into shapes for its frangibility and no good ductility.But the working life is long.
Application:cast iron is mostly used for some road covers and cookwares.however,cast steel is widely used in agricultural machinery,railway industry,ect.