Towards a Predictive, Physics-Based Model of Hydrogen-Assisted Fatigue Crack Growth: Measurements of Strain Fields and Isotope Effects

Published

November 10, 2016

Author(s)

Matthew Connolly, Andrew Slifka, Elizabeth S. Drexler

Abstract

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.

Proceedings Title

World Materials Research Institutes Forum International Workshop for Young Scientists

Conference Dates

November 14-17, 2016

Conference Location

Tsukuba, JP

Pub Type

Conferences

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Keywords

Hydrogen, Fatigue, Pipeline Steel, Neutron Diffraction, Fracture, Deuterium, Corrosion, Isotope Effects

Citation

Connolly, M. , Slifka, A. and Drexler, E. (2016), 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 30, 2024)