Organic coatings are widely used for the corrosion protection of metals. Despite a wide range of work on the degradation of organic coatings, few studies have contributed to understand the influence of the fluid flow on the degradation of organic coatings. In this study, an epoxy coating is exposed to a vertical impingement flow of a 3.5 wt% NaCl solution with a variety of flow rates. The coating degradation is monitored by electrochemical impedance spectroscopy (EIS). Equivalent circuit models are employed to interpret the EIS spectra. Atomic force microscopy (AFM) was employed to study the influence of fluid flow on the surface topology of the coating samples. We found that the coating’s barrier property deteriorates more drastically when exposed to higher flow rates for impingement flow. Coating thickness and surface roughness are significantly affected by the fluid shear and the flow rate. It is concluded that the impingement flow substantially impacts the barrier properties of epoxy coatings owing to its influence on the electrochemical properties of the coating layers and the fluid shear it creates on the coating surface.

有机涂料被广泛用于金属的腐蚀防护。尽管在有机涂层的降解方面进行了广泛的工作，但很少有研究有助于理解流体流动对有机涂层的降解的影响。在这项研究中，环氧树脂涂料以各种流速暴露于3.5 wt％NaCl溶液的垂直撞击流中。涂层的降解通过电化学阻抗谱（EIS）进行监控。等效电路模型用于解释EIS光谱。原子力显微镜（AFM）用于研究流体流动对涂层样品表面拓扑的影响。我们发现，当暴露于较高流速的冲击流中时，涂层的阻隔性能会急剧恶化。涂层的厚度和表面粗糙度受到流体剪切力和流速的显着影响。结论是，由于冲击流对环氧涂层的电化学性能和在涂层表面产生的流体剪切力的影响，因此冲击流实质上影响了环氧涂层的阻隔性能。