|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Seeing is Believing -- Understanding Environmental Degradation and Mechanical Response Using Advanced Characterization Techniques: An SMD Symposium in Honor of Ian M. Robertson
||In Situ Investigation of the Role of Slip in Crack Initiation in Hydrogen Embrittled Alloy 725
||Mengying Liu, Lai Jiang, Michael J. Demkowicz
|On-Site Speaker (Planned)
The factors responsible for hydrogen embrittlement (HE) of metals remain imperfectly understood, with prevailing theories emphasizing H-induced decohesion or H-enhanced plasticity. We use in situ tensile testing to clarify the role of slip in the initiation of intergranular cracks in alloy 725. We design specialized tensile specimens, introduce hydrogen, perform in situ tensile tests in a scanning electron microscope, and track surface plastic deformation using digital image correlation. Localized slip occurs predominantly along grain boundaries. At low H concentration, cracks initiate primarily in the vicinity of slipping boundaries, albeit not at locations of greatest slip, but rather where slip is arrested. At higher H concentration, most cracks initiate at locations with no nearby localized slip. We conclude that slip is not essential for crack initiation in HE alloy 725 and that, when it does play a role, its main effect is to generate local stress concentrations that promote decohesion.
||Mechanical Properties, Characterization,