Acidic red soil is widely distributed in southern Jiangxi and exhibits strong corrosivity, posing a significant threat to buried pipeline steels. In this work, six acidic red soil samples collected from this region were analyzed in terms of their physicochemical characteristics using pH testing and ion chromatography, and corresponding simulated soil solutions were prepared. The corrosion behavior of L415 pipeline steel in these solutions was systematically evaluated through immersion weight-loss experiments, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). All six soil solutions were found to be acidic. Variations in corrosion rate were primarily controlled by pH and ionic concentration. Lower pH values and higher ion contents resulted in more severe corrosion. The dominant corrosion products in all environments were identified as Fe3O4 and FeOOH. Electrochemical analysis further revealed the combined and complex effects of different ionic species on the corrosion mechanism of L415 steel in acidic red soil solutions. The findings of this study provide a theoretical basis for corrosion protection strategies of buried natural gas pipelines in acidic red soil regions.
Liu et al. (Thu,) studied this question.