Question

What is the element to be added to the molten cast iron in order to obtain the nodular cast iron?

• A. Cr
• B. Mn
• C. Mg
• D. Cu

Hint:

To obtain nodular cast iron, magnesium (Mg) is added to molten cast iron, which helps in forming spherical graphite.

Answer 1

The Correct Option is C

1. Introduction to Nodular Cast Iron:
Nodular cast iron, also known as ductile iron, is cast iron that has been modified to form nodular (spherical) graphite, rather than the typical flake graphite structure seen in gray cast iron. 2. Role of Magnesium:
To obtain nodular cast iron, magnesium (Mg) is added to molten cast iron. Magnesium reacts with sulfur and oxygen in the molten iron to convert the graphite from flakes to spherical nodules. 3. Effect of Magnesium on the Structure:
The spherical shape of the graphite in nodular cast iron significantly improves its mechanical properties, especially its ductility and toughness, making it more suitable for use in structural components.