Question

Which of the following is/are the causes for the poor oxidation resistance of metal oxide with high Pilling and Bed worth ratio?

(a) Large compressive stresses in the oxide

(b) Cracking

(c) Spalling

(d) Large compressive stresses in the oxide, cracking and spalling

This question was posed to me during an online interview.

This key question is from High-Temperature Corrosion in chapter High Temperature Corrosion of Corrosion Engineering

Answer 1

Correct answer is (d) Large compressive stresses in the oxide, cracking and spalling

To explain I would say: Metal oxides with a value greater than 1 Pilling and Bed worth ratio have poor oxidation resistance due to large compressive stresses in the oxide, cracking, and spalling.