Question

Which of the following type of cast irons that exhibits graphitization?

(a) Grey cast iron

(b) Nodular cast iron

(c) Malleable cast iron

(d) Grey cast iron, nodular cast iron, and malleable cast iron

This question was addressed to me at a job interview.

My question is taken from Eight Forms topic in division Eight Forms of Corrosion of Corrosion Engineering

Answer 1

The correct choice is (a) Grey cast iron

Explanation: Graphitization occurs only in grey cast iron whereas it doesn’t occur in nodular, malleable, and white cast iron as the graphite network is not present to hold together at the surface.