Question

Select the correct statement related to increasing the carbon content in steel from 0.2 to 0.9 percent.
1. Increasing the carbon content in steel decreases the yield stress and does not affect the ductility.
2. Increasing the carbon content in steel decreases the yield stress and increases the ductility.
3. Increasing the carbon content in steel increases the yield stress and reduces the ductility.
4. Increasing the carbon content in steel does not have any effect on the yield stress or ductility.

Answer 1

Correct Answer - Option 3 : Increasing the carbon content in steel increases the yield stress and reduces the ductility.

Explanation:

Carbon steel is an alloy of iron and carbon.

As the carbon content increases:

1. The ultimate strength of steel increases.
2. The elongation before fracture decreases.
3. The ductility of the metal decreases.
4. Increasing carbon also reduces the weldability, especially above 0.25% carbon.
5. Plasticity and ductility are similar.

Generally, carbon is the most important commercial steel alloy. Increasing carbon content increases hardness and strength and improves hardenability.