TEM investigation of SCC crack tips in high Si stainless steel tapered specimens

Aäron Penders, Milan Konstantinovic, Wouter Van Renterghem, Rik-Wouter Bosch, Dominique Schryvers

Research outputpeer-review


The stress corrosion cracking (SCC) mechanism is investigated in high Si duplex stainless steel in a simulated PWR environment based on TEM analysis of FIB-extracted SCC crack tips. The microstructural investigation in the near vicinity of SCC crack tips illustrates a strain-rate dependence in SCC mechanisms. Detailed analysis of the crack tip morphology, that includes crack tip oxidation and surrounding deformation field, indicates the existence of an interplay between corrosion- and deformation-driven failure as a function of the strain rate. Slow strain-rate crack tips exhibit a narrow cleavage failure which can be linked to the film-induced failure mechanism, while rounded shaped crack tips for faster strain rates could be related to the strain-induced failure. As a result, two nominal strain-rate-dependent failure regimes dominated either by corrosion or deformation-driven cracking mechanisms can be distinguished.
Original languageEnglish
Pages (from-to)767-777
Number of pages12
JournalCorrosion Engineering, Science and Technology
Issue number8
StatePublished - 14 Feb 2021

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