X60M管线钢输氢适用性评价OA

To assess the hydrogen compatibility and applicability of domestically produced X60 pipeline steel for hydrogen service and to address the material selection challenges associated with high-strength,large-diameter hydrogen pipelines,a comprehensive evaluation was conducted in this study.Fifteen X60M grade longitudinal submerged arc welded pipes produced by major domestic steel mills were selected.According to relevant domestic and international standards and the proposed engineering conditions,three mechanical tests including slow strain rate tensile test,fracture toughness test,and fatigue crack growth rate test were performed.Key performance indicators included loss in percentage reduction of area,plane-strain fracture toughness(Kic),and fatigue life.Results demonstrated that the percentage reduction of area ranged from 22.75%to 33.72%for base metal and from 29.22%to 37.67%for weld metal—both well within the acceptance threshold of≤40%;plane-strain fracture toughness values exceeded 70 MPa·m 1/2 across all critical microstructural regions(base metal,weld metal,and heat-affected zone);and the predicted fatigue life determined using the experimentally measured fatigue crack growth rate,surpassed the minimum design requirement of 3,500 cycles.Experimental results demonstrate that,by appropriately controlling chemical composition,nonmetallic inclusions,and grain size,the existing X60M pipeline steel used for natural gas transportation in China exhibits good hydrogen compatibility and is suitable for pure hydrogen pipeline construction,thereby providing a reliable technical reference for material selection of high-strength large-diameter hydrogen pipelines.