why are cast iron made with carbon?

Question

benefits..

Answer 1

It's right that the amount of carbon in iron indicates its strength.

You can read it's benefits at

http://www.answers.com/topic/cast-iron
http://www.fantes.com/cookware.htm

thanks

Answer 2

The carbon adds strength and hardness. Cast iron contains more carbon than steel does. The difference between the two is that in steel all the carbon is either dissolved in the metal or chemically combined as iron carbide, while in cast iron free carbon is present as graphite.

Edit - I misstated this based on dimly remembered metallurgy classes. The carbon in cast iron can be either graphite or carbide. What distinguishes it is that due to an overabundance of carbon, the graphite or carbide in cast iron precipitates out of solution, giving you carbon-rich regions throughout the metal. In steel, the carbon, in whatever form, stays dissolved in the metal.

Answer 3

To make iron, you take iron ore from the earth & you refine it or convert it into iron. This iron contains a lot of carbon and is called cast iron.

So the answer to your question is: When iron is made, it naturally contains alot of carbon (from the refining process) and this is allowed to happen because the iron's hardness is useful. However, it's also brittle and can rust.

So, people make steel from this type of iron by removing a lot of the carbon & adding other metals to improve its usefulness.

Answer 4

It is not, carbon is added to cast iron to make steel.

Answer 5

To harden it. The amount of carbon in iron dictates its strength.