Pilling-Bedworth theory

In the case of thick oxide formation at high temperature, the Pilling-Bedworth theory may have a limited applicability. Explain why this may be the case. 

Chapter 10 deals with high temperature corrosion, in which the thermodynamics and kinetics of metal oxidation are included. The Pilling Bedworth Ratio and Wagner s parabolic rate constant theories are defined as related to formation of metal oxide scales, which are classified as protective or nonprotec-tive. 

The mechanism and the theories of linear oxidation must be discussed with reference to specific examples. This will shortly be done, but it will be helpful to return first of all to the theories of Pilling and Bedworth. 

High-temperature corrosion is a form of corrosion that does not require the presence of a liquid electrolyte. Sometimes, this type of damage is called dry corrosion or scaling. The first quantitative approach to oxidation behavior was made in the early 1920s with the postulation of the parabolic rate theory of oxidation by Tanunaim and, independently, by Pilling and Bedworth. 

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