INVESTIGATING THE ROLE OF HYDROGEN ON STRESS CORROSION CRACKING BY MICROMECHNAICAL TESTING

摘要

A high-resolution characterization approach wasemployed to understand the effect of hydrogen on stresscorrosion cracking (SCC) in austenitic alloys. Micromechanicaltesting, in the form of nano-indentation, onnear (001) grains on alloys ranging from 12-70% Ni wereperformed with and without electro-chemical hydrogencharging.The deformed region was further examined byTEM and the role of hydrogen on the dislocation mobilityanalyzed and compared between the different alloys.Furthermore, a coupled elastoplastic-transient hydrogendiffusion model was implemented using the UMAT-HT usersub-routine, to model the effect of hydrogen on materialsunder deformation. To validate this approach, simulatedload- displacement curves are compared to those producedduring this study and in the wider literature. Based on theresults obtained during this study, the effect of hydrogenas a mechanism on SCC is discussed.