About this Abstract |
| Meeting |
2026 AWS Professional Program
|
| Symposium
|
2026 AWS Professional Program
|
| Presentation Title |
Evaluation of Hydrogen Embrittlement Susceptibility in Flat X65 Pipeline Steel Weld Specimens |
| Author(s) |
Fernando Romero Consuegra, Boian T Alexandrov |
| On-Site Speaker (Planned) |
Fernando Romero Consuegra |
| Abstract Scope |
The objective of this study is to evaluate the effect of weld metal and heat affected zone (HAZ) microstructures on the hydrogen embrittlement (HE) susceptibility in API X65 pipeline steel weldments. We utilized the delayed hydrogen cracking test (DHCT), per standard AMPP TM21453, by applying a constant tensile load below the yield strength to unnotched specimens with in-situ electrolytic hydrogen charging. Time-to-failure (TTF) and sustained mechanical energy (SME) of test specimens are considered for ranking the HE susceptibility of different X65 multipass weld combinations. SME quantifies the energy associated with the HE nucleation and propagation mechanisms.
Previous DHCT work showed the effect of natural stress concentration from weld cap and root pass geometries on the HE susceptibility of X65 welds. Test results were compared to published data from slow strain rate testing (SSRT) and fracture toughness tests (FTT) of pipeline steel welds under high-pressure hydrogen environments. It was demonstrated that, compared to DHCT, SSRT required up to two orders of magnitude higher SME to generate HE failure. This was attributed to enhanced localized plastic strain, which is required to achieve critical hydrogen concentration for crack nucleation and propagation in the necking region. The SME in DHCT and the provisional fracture resistance (JQH) in literature FTT had overlapping ranges, potentially due to similarities in the crack propagation mechanisms.
The current scope of work evaluates the effect of microstructure and hardness on the HE in X65 steel welds. Flat gauge section specimens, extracted from a range of GMAW and SAW weldments with varying weld metal and HAZ strength, were subjected to DHCT. The test results are utilized in a larger scale study, aiming to establish correlation between DHCT and FTT results, and develop a database of HE susceptibility in pipeline steel welds. |
| Proceedings Inclusion? |
Undecided |