Correlative NanoSIMS and electron microscopy methods for understanding deuterium distributions after fatigue testing of 304/304L stainless steel in deuterated water. (31st July 2020)

• Record Type: Journal Article
• Authors: McMahon, Greg; Miller, Bryan D.; Burke, M. Grace
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 38(2020)
• Page Start: 20042
• Page End: 20052
• Publication Date: 2020-07-31
• Subjects: NanoSIMS -- TEM -- EBSD -- Fatigue -- Deuterium -- Hydrogen-assisted cracking; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.05.002
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: There is no single methodology that can map the distribution of hydrogen and relate it to specific crystallographic phases or defect structures. Here, we present a case study demonstrating two methodologies towards achieving this goal: Correlating nanoscale secondary ion mass spectrometry (NanoSIMS) deuterium maps with electron backscattered diffraction (EBSD) data ahead of crack tips in a 304 stainless steel sample fatigue tested in deuterated water, and secondly correlating NanoSIMS deuterium maps with (scanning) transmission electron microscopy ((S)TEM) data from focused ion beam (FIB) lift-out samples. Correlating NanoSIMS/EBSD images, we confirmed an association of deuterium with martensitic lath structures. Furthermore, we discovered localized enrichments of deuterium along the martensitic laths, with a higher associative preponderance to ε−martensite. Applying correlative NanoSIMS/(S)TEM imaging of the fracture surface, we found deuterium accumulation at the metal oxide interface. However, in the pre-crack region, the deuterium was clearly concentrated underneath the oxide layer. Graphical abstract: Image 1 Highlights: Correlative imaging shows associations of 2 H and BCC phases in stainless steel. Deuterium localizes at ε-martensite in stainless steel fatigue tested in D2 O. 2 H is co-located with a Ni-enriched layer formed below the surface oxide.