On the role of precipitates in hydrogen trapping and hydrogen embrittlement of a nickel-based superalloy. (January 2019)

• Record Type: Journal Article
• Authors: Zhang, Zhenbo; Moore, Katie L.; McMahon, Greg; Morana, Roberto; Preuss, Michael
• Is Part Of: Corrosion science. Volume 146(2019)
• Page Start: 58
• Page End: 69
• Publication Date: 2019-01
• Subjects: Nickel-based superalloy -- Hydrogen embrittlement -- NanoSIMS -- Hydrogen adsorption -- Precipitates; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2018.10.019
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Successfully imaged H concentrations in δ phase and carbonitrides, and at their interfaces with the matrix using NanoSIMS in alloy 718. δ attracts a higher concentration of H than the matrix while carbonitrides adsorb much less. No H segregation was observed at the interfaces. The higher vulnerability of δ in H induced cracking is attributed to its higher capacity in H adsorption, and vice versa for carbonitrides. Abstract: Here we report imaging of hydrogen/deuterium concentrations in δ phase and carbonitrides, and at their interfaces with the matrix in a nickel-based superalloy using Nanoscale Secondary Ion Mass Spectrometry. It is found that δ phase attracts a higher concentration of hydrogen than the matrix during cathodic charging, while carbonitrides adsorb much less. No hydrogen segregation was observed at the interfaces. Detailed electron microscopy analysis of the H-charged samples after tensioning to failure demonstrates that the higher vulnerability of δ in hydrogen induced cracking is largely attributed to its higher capacity in hydrogen adsorption, and vice versa for carbonitrides.