Abstract In this paper, local corrosion pits were stimulated by arc defect pits (ADP) of different sizes. The corrosion of specimens was tested in high-speed flow CO2-saturated NACE solution. Electrochemical corrosion characteristics were monitored online. The characteristics of corrosion scale were then investigated by SEM and Raman spectroscopy. The results showed deepening and expansion of corrosion pits will occur at the same time under flow conditions for shallow pits. The development of corrosion pits at certain depth led to formation of complete corrosion scale, which inhibited further corrosion. As corrosion pits deepened, expansion process decreased and deepening rates accelerated. In-depth analysis suggested that corrosion rates were mainly affected by mass transfer rate and integrity of formed corrosion scale.

中文翻译：

---

流动条件下X80管线钢局部腐蚀坑的形成机制

摘要 本文通过不同尺寸的电弧缺陷坑（ADP）激发局部腐蚀坑。试样的腐蚀在高速流动的 CO2 饱和 NACE 溶液中进行测试。在线监测电化学腐蚀特性。然后通过扫描电镜和拉曼光谱研究腐蚀垢的特征。结果表明，浅坑在流动条件下会同时发生腐蚀坑的加深和扩大。腐蚀坑在一定深度处的发展导致形成完整的腐蚀垢，从而抑制了进一步的腐蚀。随着腐蚀坑的加深，膨胀过程减少，加深速度加快。深入分析表明，腐蚀速率主要受传质速率和形成的腐蚀垢的完整性的影响。