Towards a Predictive, Physics-Based Model of Hydrogen-Assisted Fatigue Crack Growth: Measurements of Strain Fields and Isotope Effects
Matthew Connolly, Andrew Slifka, Elizabeth S. Drexler
A predictive, physics-based model of hydrogen-assisted fatigue crack growth in pipeline steel is necessary to provide accurate lifetime predictions for current and future pipelines. It is necessary to inform such a model with physical data, namely crack tip strains and hydrogen diffusion rates. In this paper, we present measurements of the elastic crack tip deformation near cracks grown via fatigue in air and in a hydrogen environment. Drastic differences in both magnitude and spatial extent of the crack tip strain fields grown in each condition are demonstrated. We then present tensile and fatigue data for steel specimens measured in-air, in-hydrogen, and in-deuterium, which present a measure of the role diffusion plays in hydrogen embrittlement and hydrogen assisted fatigue crack growth. A large diffusion effect is observed for hydrogen assisted fatigue crack growth rate, while only a small dependence is observed for hydrogen embrittlement measurements.
World Materials Research Institutes Forum International Workshop for Young Scientists
, Slifka, A.
and Drexler, E.
Towards a Predictive, Physics-Based Model of Hydrogen-Assisted Fatigue Crack Growth: Measurements of Strain Fields and Isotope Effects, World Materials Research Institutes Forum International Workshop for Young Scientists, Tsukuba, JP, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=921733
(Accessed December 7, 2023)