The occurrence and development mechanism of internal local corrosion has always been a controversial topic, and especially under flow conditions. In this paper, an improved high shear force loop was experimentally used, and local flow field is induced by simulating corrosion defects on the surface of X80 pipeline steel specimens. The characteristics of corrosion products deposited on the surface of specimens in CO₂-saturated NACE solution were investigated by means of electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectrometry (EDS). The 3D micromorphology of the corrosion test surface after remove the corrosion scale used to measure the size of localized corrosion pit. Under the influence of local defects, the wall shear stress (WSS) and turbulent kinetic energy of local flow fields enhanced significantly, and pressure fluctuations in local flow field were induced. The results showed that the characteristics of surface corrosion products varied with flow velocity. The corrosion scales formed in various regions of specimens with defects exhibited different surface micro-morphologies and chemical compositions. Overall, these data offer new perspectives for better understanding the mechanisms behind local corrosion.

内部局部腐蚀的发生和发展机理一直是一个有争议的话题，尤其是在流动条件下。本文采用改进的高剪切力回路进行实验，并通过模拟X80管线钢试样表面的腐蚀缺陷来诱发局部流场。在CO _2中沉积在试样表面的腐蚀产物的特性通过电化学阻抗谱（EIS），扫描电子显微镜（SEM），X射线衍射（XRD）和能量色散谱（EDS）研究了饱和NACE溶液。去除用于测量局部腐蚀坑尺寸的腐蚀水垢后，腐蚀测试表面的3D微观形态。在局部缺陷的影响下，局部流场的壁面剪应力（WSS）和湍动能明显增强，并引起局部流场的压力波动。结果表明，表面腐蚀产物的特性随流速的变化而变化。在具有缺陷的样品的各个区域中形成的腐蚀垢表现出不同的表面微观形态和化学组成。总体，