Question

The carbon content of cast iron ranges from _______.
1. 10 to 12%
2. 2 to 4%
3. 8 to 14%
4. 12 to 14%

Answer 1

Correct Answer - Option 2 : 2 to 4%

Explanation:

Cast iron

• Cast iron is an alloy of iron, carbon and silicon and it is hard and brittle.
• Carbon content in CI may be within 1.7% to 3% and carbon may be present as free carbon or iron carbide Fe3C.
• In general, the types of cast iron are (a) grey cast iron and (b) white cast iron (c) malleable cast iron etc

Wrought iron

• Wrought iron is a very pure iron where the iron content is of the order of 99.5%. 
• It usually contains less than 0.1% carbon and 1 or 2% slag.
• It is produced by re-melting pig iron and some small amount of silicon, sulphur, or phosphorus may be present.
• It is tough, malleable and ductile and can easily be forged or welded.
• It cannot however take sudden shock. Chains, crane hooks, railway couplings and such other components may be made of this iron.

Pig iron 

• Pig iron is an intermediate product of the iron industry. 
• Pig iron has a very high carbon content, typically 3.8–4.7%, along with silica and other constituents of dross, which makes it very brittle, and not useful directly as a material except for limited applications.

Steel 

• Steel is basically an alloy of iron and carbon in which the carbon content can be less than 1.7% and carbon is present in the form of iron carbide to impart hardness and strength.
• Two main categories of steel are (a) Plain carbon steel and (b) alloy steel.
• Thus, wrought iron is an iron alloy with a very low carbon (less than 0.08%) content in contrast to cast iron.