Hydrogen Stress Cracking Resistance of Seamless Pipes for Hydrogen Storage and Transport Applications

Abstract

Abstract With an increasing number of projects involving production and use of low-carbon hydrogen, the compatibility with hydrogen gas of assets for storage and transport shall be guaranteed. Indeed, hydrogen is a threat for steel equipment integrity as it promotes subcritical crack growth. In this paper the fracture toughness resistance of a selection of seamless pipes and girth weld for pipeline, OCTG and pressure vessel in pure H2 is investigated. It covers a large variability of materials in terms of microstructures (ferrite-pearlite, bainite, martensite) and yield strengths (from 400 MPa to 700 MPa). Recommendations and requirements provided by ASME B31.12 standard have been followed for this qualification program. Fracture toughness evaluations were performed via fatigue pre-cracked bolt-load specimens exposed to 100 bar hydrogen gas during 1000 h at room temperature. All materials presented hydrogen stress intensity factor thresholds KIH largely above 55 MPa.m1/2, compliant with the ASME B31.12 option B requirement that defines materials requirements for hydrogen service. Data provided can be used for building Failure Assessment Diagram, decisive tool for predicting the safe domain of usage of structures.