Evaluation of Fracture Toughness of Welded Line Pipe Steels for Hydrogen Gas Transportation Based on ASME B31.12 and Alternative Test Method Development

• DOI: 10.1115/ipc2024-132910
• Publication Date: 2024-12-13T19:19:49Z
• Authors: Eun Jung Seo; Amrita Bag; Michael J. Gaudet; Shaojie Chen; Greg Lehnhoff; Muhammad Rashid; Muhammad Arafin
• Keywords: Line (geometry)

Abstract A high-strength line pipe steel grade, namely API X65, has been developed and qualified for its use under pressurized hydrogen gas following the ASME B31.12 code. The bolt-load compact specimens taken from base metal, heat-affected zone, weld seam of electric resistance welded (ERW) pipes were tested using a constant displacement method in 100% at pressure up to 13.8 MPa (2000 psi) 1000 hours. All fracture toughness testing was conducted RINA Consulting – Centro Sviluppo Materiali SpA EWI Hydrogen Environment Testing Lab, approximately 50 different heats produced Evraz North America (ENA). At surface specimens, no significant crack extension observed; beyond fatigue pre-crack smaller than 0.25 mm after preloading exposure. Scanning electron microscopy (SEM) fractographs revealed dimpled front pre-crack, i.e. hydrogen-associated brittle feature noted. Based on these results, minimum value threshold stress intensity factor, KIH, calculated be 70–80 MPa√m all i.e., fulfilling qualification criteria (KIH > 55 MPa√m) described code Option B. lessons learned during testing, ongoing efforts develop alternative methods, including elastic-plastic (i.e., ASTM E1820) implications future will discussed.