Quantification of growth kinetics and adherence of oxide scales formed on Ni-based superalloys at high temperature

Abstract

Cyclic and isothermal oxidation behaviors of first and fourth-generation superalloys AM1 and MCNG were investigated to evaluate the ability of the scratch test to quantify the adhesion of multi-layered oxide scales. Effects of sulfur content and of scale thickness were studied independently. Available models lead to large discrepancies in the calculated work of adhesion values with the evaluation of the residual stress being the largest source of error. Nevertheless, models can assess the effect of sulfur content and the scratch test can be used to correlate the long-term cyclic oxidation behavior and the adhesion of oxide scales.

Characterisation of oxide scale adherence after the high temperature oxidation of nickel-based superalloys

“…In a previous work [14], the ability of the scratch test to quantify the adherence of oxide scale formed on Ni-base superalloys after short term isothermal oxidation was evaluated. However, the mechanical behaviour of thin film/ substrate systems under sliding indenter loading is complex.…”

Microstructure And Mechanical Properties Of Crofer 22 APU Ferritic Stainless Steel

“…The first acoustic emission peak observed and the variation of the frictional force provide complementary information for critical load measurements [15]. The multilayered structure of the oxide scale must be accurately known for a correct analysis of scratch-test results.…”

“…The multilayered structure of the oxide scale must be accurately known for a correct analysis of scratch-test results. Indeed, the layering of the oxide scale influences the values measured for the critical load [15].…”

“…It is important to point out that the studied case of the oxide scale adherence on a steel is more complex than that of a film deposited on a substrate. For a thermally grown oxide, it may be necessary to distinguish the effect of oxide scale thickness and the effect of oxidation duration on the adhesion behavior [15].…”

“…Difficulties include complicated stress-strain field, different failure modes occurring at the same time, numerous intrinsic and extrinsic parameters. Therefore, the technique is usually regarded as semi quantitative [15].…”