Question

At ________ iron changes its BCC structure to FCC.

(a) 308^oC

(b) 568^oC

(c) 771^oC

(d) 906^oC

This question was addressed to me in an interview for job.

I want to ask this question from Types of Solids, Crystal Structures and Lattices in section Solid Solutions & Crystallography of Engineering Material & Metallurgy

Answer 1

Correct answer is (d) 906^oC

To explain: Similar to metallic crystals, a few non-metallic crystals also change form due to temperature and pressure differences. This process is termed as polymorphism. Iron changes from BCC at room temperature to FCC form at 906^oC.