The corrosion of carbon steel condensate water pipelines significantly compromises the safety of natural gas production. In this study, a corroded carbon steel pipeline retrieved from an operational facility was thoroughly analyzed to determine the root causes of corrosion. The results present a failure analysis that moves beyond identifying oxygen-induced corrosion as the root cause. Through multi-technique characterization, we establish a direct link between the spatial variation in corrosion severity/product distribution and localized hydrodynamic conditions. A synergistic mechanism is revealed: at the high-turbulence elbow, intense fluid shear strips protective Fe 3 O 4 layers while enhanced oxygen mass transfer promotes non-protective FeOOH/Fe 2 O 3 formation. In contrast, stable Fe 3 O 4 scales form in calmer regions. These findings provide a nuanced mechanistic understanding for designing targeted anti-corrosion strategies in condensate water systems. • Fe₂O₃, Fe₃O₄, and FeOOH are the main corrosion products. • Links spatial corrosion variation to localized flow conditions, not just velocity. • A corresponding formation pathway for these corrosion products is proposed.
Sun et al. (Sun,) studied this question.