We combine welding process modelling with deformation-diffusion-fracture (embrittlement) simulations to predict failures in hydrogen transport pipelines. The focus is on the structural integrity of seam welds, as these are often the locations most susceptible to damage in gas transport infrastructure. Finite element analyses are conducted to showcase the ability of the model to predict cracking in pipeline steels exposed to hydrogen-containing environments. The validated model is then employed to quantify critical H$_2$ fracture pressures. The coupled, phase field-based simulations conducted provide insight into the role of existing defects, microstructural heterogeneity, and residual stresses. We find that under a combination of deleterious yet realistic conditions, the critical pressure at which fracture takes place can be as low as 15 MPa. These results bring new mechanistic insight into the viability of using the existing natural gas pipeline network to transport hydrogen, and the computational framework presented enables mapping the conditions under which this can be achieved safely.

翻译：我们将焊接过程建模与变形-扩散-断裂（脆化）模拟相结合，预测氢输运管道中的失效行为。研究重点聚焦于焊缝的结构完整性，因为焊缝通常是气体输运基础设施中最易受损的部位。通过有限元分析，展示了该模型预测含氢环境下管线钢裂纹扩展的能力。经验证的模型被用于定量评估临界H₂断裂压力。基于相场理论的耦合模拟揭示了既有缺陷、微观结构非均匀性以及残余应力的作用机制。研究发现，在不利因素的组合且具备现实可能性的条件下，断裂发生的临界压力可低至15 MPa。这些结果从机理层面为利用现有天然气管网输运氢气的可行性提供了新见解，而本文提出的计算框架则能绘制出实现安全输运的条件图谱。