掺氢环境下含腐蚀缺陷X52天然气管道的结构强度失效机理研究

Structural strength failure mechanism of X52 natural gas pipeline with corrosion defects under hydrogen-blended environment

[目的]旨在探究掺氢环境下含腐蚀缺陷管道的结构强度劣化规律。[方法]基于试验数据分析X52钢在不同掺氢比例下的承载性能,采用非线性有限元方法研究X52掺氢天然气管道在不同腐蚀缺陷下的结构强度失效机理。[结果]研究结果表明:掺氢比例增大到50.0%时,管道在组合载荷下达到失效的位移最小为2.58 mm,结构韧性劣化程度较大;掺氢比例为25.0%时,缺陷深度越大,结构失效程度越严重,通过对正方形和圆形缺陷的对比,发现正方形缺陷的最大应力高于圆形缺陷。[结论]基于材料性能构建的含缺陷管道模型能够实现对不同掺氢环境下天然气管道服役状态结构承载力劣化程度的评估,所做研究可为新能源管道设计及健康监测提供工程化建议。

[Objective]This study aims to explore the structural strength deterioration mechanism of pipelines with corrosion defects in hydrogen-blended environments.[Methods]Based on the experimental data,an analysis is made of the load bearing performance of X52 steel under different levels of hydrogen blending,and the structural strength failure mechanism of an X52 hydrogen-blended natural gas pipeline under different corrosion defects is described using the nonlinear finite element method.[Results]When the hydrogen blend level increases to 50.0%,under a combined load,the pipeline reaches minimum displacement failure at 2.58 mm,and the structural toughness deteriorates to a greater degree;at a hydrogen blend level of 25.0%,the defect depth is greater and the degree of structural failure more serious;comparing square and circular defects,the maximum stress of the square defects is higher than that of the circular defects.[Conclusions]The material property-based defective pipeline model can realize the assessment of the structural bearing capacity deterioration of natural gas pipelines under different hydrogen-blending conditions,providing engineering suggestions for the design and health monitoring of new energy pipelines.