Hydrogen uptake and embrittlement behavior in pipeline steels: Insights from slow strain rate testing and synchrotron micro-CT imaging
Date
2025-02
Authors
Jack, Tonye
Webb, Mark Adam
Rahman, K.M. Mostafijur
Fazeli, Fateh
Szpunar, Jerzy
Journal Title
Journal ISSN
Volume Title
Publisher
Engineering Failure Analysis
ORCID
Type
Article
Degree Level
Abstract
Hydrogen embrittlement (HE) presents a major challenge to the integrity of steel pipelines, often leading to premature failure. Traditional methods using two-dimensional (2D) analysis of damaged structures, often overlook critical features related to failure. Hence, this study investigates the hydrogen embrittlement susceptibility of two pipeline steels, X60 and X65, using a combination of mechanical testing, hydrogen diffusion and trapping studies, microstructural characterization, and synchrotron micro-computed tomography (micro-CT) imaging. The results highlight the critical role of hydrogen trapping and retention in HE, with steel microstructure significantly affecting hydrogen uptake and diffusion as well as crack nucleation and propagation. Synchrotron micro-CT imaging provided more accurate crack pattern assessments than traditional 2D methods, revealing potential misinterpretations from 2D cross-sectional analysis. This study concludes that simultaneous hydrogen ingress and mechanical loading is more damaging than pre-charging with high hydrogen concentrations, and that hydrogen retention capacity plays a greater role in embrittlement behavior than crack initiation. The failure mechanism of the hydrogen-charged steels shifted from being plasticity-based to decohesion-driven, based on the hydrogen content and retention in the steel, which is in line with the unified HELP+HEDE model.
Description
Keywords
Pipeline steel, Hydrogen embrittlement, Synchrotron micro-CT imaging, Microstructure, Tensile testing, Thermal desorption analysis
Citation
Jack, T. A., Webb, M. A., Rahman, K. M. M., Fazeli, F., & Szpunar, J. (2025). Hydrogen uptake and embrittlement behavior in pipeline steels: Insights from slow strain rate testing and synchrotron micro-CT imaging. Engineering Failure Analysis, 172, https://doi.org/10.1016/j.engfailanal.2025.109419
Degree
Department
Program
Advisor
Committee
Part Of
item.page.relation.ispartofseries
DOI
https://doi.org/10.1016/j.engfailanal.2025.109419