The corrosion mechanism of X80 steel in simulated solutions of acid red soil and product oil sediment under mechano-electrochemical interaction (MEI) was researched to build a new finite element model through multi-physical field coupling simulation technology. Based on the new model, the effect of external wall defect growth on the internal wall corrosion of oil pipelines was analyzed in detail. The results showed that the distributions of stress and corrosion of the internal wall were extremely affected by the external wall defect depth, and the corrosion rate of the internal wall was enlarged remarkably by the external wall defect growth. Moreover, attributing to the local galvanic cell effect under MEI, the growth rates of corrosion defects in the depth and length directions of the external defect were accelerated because these directions were associated with larger stress and equivalent to the anode, but the corrosion rate in the width direction of the external defect was inhibited because this direction was associated with smaller stress and equivalent to the cathode.

中文翻译：

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力-电化学相互作用下外壁缺陷生长对输油管道内壁腐蚀的影响

通过多物理场耦合仿真技术，研究X80钢在机械-电化学相互作用（MEI）作用下在酸性红土和成品油沉积物模拟溶液中的腐蚀机理，建立新的有限元模型。基于新模型，详细分析了外壁缺陷生长对输油管道内壁腐蚀的影响。结果表明，外壁缺陷深度对内壁应力分布和腐蚀影响极大，外壁缺陷的生长显着增大了内壁腐蚀速率。此外，归因于 MEI 下的局部原电池效应，