1 Introduction In the past,several oxide scale failure models were developed for different types of failure,and approaches exist to combine these models with oxide failure diagrams.The most well known concept is described in EPRI report FP686 from 1978 which served as a basis for the assessment of strain tolerance 1 Introduction In the past, several oxide scale failure models were developed for different types of failure, and approaches exist to combine these models with oxide failure diagrams. The most known concept is described in EPRI report FP686 from 1978 which served as a basis for for the assessment of strain tolerance