石油科学通报2026，Vol.11Issue(4)：1146-1159,14.DOI:10.3969/j.issn.2096-1693.2026.02.042
X70管道焊缝中的氢脆化阈值:疲劳性渐进劣化与掺氢天然气输送的关键安全运行限值
Hydrogen embrittlement thresholds in X70 pipeline welds:Fatigue-propa-gative degradation and critical safe-operation limits for hydrogen-blended natural gas transmission
摘要
Abstract
Against the backdrop of the strategic imperative for carbon peak and carbon neutrality,the global energy infrastruc-ture is undergoing a comprehensive restructuring toward cleaner,low-carbon,efficient,and secure energy architectures.Hydro-gen energy has emerged as a critical secondary energy vector,playing an increasingly vital role in facilitating the transition to sustainable energy systems.The integration of hydrogen into natural gas pipelines represents a technologically and economically viable pathway,allowing the repurposing of existing infrastructure for large-scale,cost-efficient hydrogen transportation.Howev-er,the permeation and interaction of hydrogen with pipeline steels can induce hydrogen embrittlement,a degradation mechanism that significantly compromises structural integrity and operational safety.A fundamental understanding of hydrogen embrit-tlement mechanisms,along with the development of effective mitigation strategies for pipeline materials in hydrogen-blended service environments,is therefore essential to ensure the reliability and safety of energy infrastructure throughout this transitional phase.This study systematically evaluates the hydrogen embrittlement behavior of X70 pipeline steel welds in hydrogen-blended natural gas systems by means of slow strain rate tensile tests and fatigue crack propagation experiments.The experimental matrix encompasses hydrogen blending ratios of 10%,20%,and 100%,in conjunction with hydrogen charging durations of 12 hours,24 hours,and 48 hours,to comprehensively assess their effects on mechanical properties,fracture mechanisms,and hydrogen embrittlement susceptibility in the weld region.Results reveal that under cyclic loading,the weld zone displays markedly higher susceptibility to hydrogen embrittlement relative to the base metal.A non-monotonic dependence of embrittlement sensitivity on hydrogen concentration is observed,with a critical threshold identified at 20%hydrogen blending ratio,where the hydrogen embrittlement coefficient attains a maximum value of 15.22%.The fracture morphology transitioned from typical ductile dimples to a quasi-cleavage mixed mode.This phenomenon is attributed to the irreversible segregation of hydrogen at defects such as grain boundaries.The segregated hydrogen reduces the local interatomic cohesion through the hydrogen-enhanced decohesion mechanism,thereby inducing brittle fracture and exacerbating the material's embrittlement tendency.Furthermore,the study identified 24 hours as the most sensitive time node for the response of X70 pipeline to the hydrogen environment.This research reveals the performance degradation mechanism and micro-damage mechanism of X70 steel welds in hydrogen-blended environ-ments,providing an important theoretical basis and experimental data support for the safe operation control,life assessment,and integrity management of hydrogen-blended natural gas pipelines.关键词
X70管线钢/氢脆/慢应变速率拉伸/疲劳裂纹扩展/断口形貌/掺氢天然气Key words
X70 pipeline steel/hydrogen embrittlement/slow strain rate stretching/fatigue crack propagation/fracture morphology/hydrogen-doped natural gas分类
能源科技引用本文复制引用
廉欣然,邓嵩,班久庆,闫霄鹏,王鑫,杨威,刘刚..X70管道焊缝中的氢脆化阈值:疲劳性渐进劣化与掺氢天然气输送的关键安全运行限值[J].石油科学通报,2026,11(4):1146-1159,14.基金项目
2025年江苏省研究生科研与实践创新计划,资助编号KYCX25_3337 （）
