Abstract Clay is a naturally occurring material, and it has been utilized for many industrial processes. In this study, two types of clay namely white clay (WC) and black clay (BC) was used for this investigation. The corrosion performance of the clay samples was carried out using mild steel and galvanized pipes under a buried condition in the field and laboratory exposure studies were carried in the clay extracts. Generally mild steel (MS) and galvanized iron (G.I) are being used as an encasing material for earthing applications. In some places, the soil was enriched with acidic clay, and it causes corrosion of the MS and G.I and it needs periodic replacement of pipes. In this context, a detailed study has been carried out to evaluate the relative corrosion performance of the MS and G.I exposed to the clay environment. Electrochemical corrosion behavior of MS and G.I in clay medium were carried out by using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The corrosion product formation was characterized by X-Ray Diffraction and Carbon Hydrogen Nitrogen Spectrum analysis. The surface morphology of MS and G.I after the exposure was characterized by Scanning Electron Microscopy (SEM) studies. The results proved that G.I in clay soil was severely affected by corrosion. The reason may be attributed to the insufficient thickness of the zinc coating and the presence of microbes which enhanced the G.I corrosion.

中文翻译：

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低碳钢和镀锌铁在粘土环境中的腐蚀性能

摘要 粘土是一种天然存在的材料，已被用于许多工业过程。在这项研究中，本研究使用了两种粘土，即白粘土 (WC) 和黑粘土 (BC)。粘土样品的腐蚀性能是在现场埋地条件下使用低碳钢和镀锌管进行的，并在粘土提取物中进行了实验室暴露研究。通常低碳钢 (MS) 和镀锌铁 (GI) 被用作接地应用的外壳材料。有的地方土壤富含酸性粘土，对MS和GI造成腐蚀，需要定期更换管道。在这方面，已经进行了详细的研究来评估暴露在粘土环境中的 MS 和 GI 的相对腐蚀性能。采用电化学阻抗谱（EIS）和动电位极化法研究了MS和GI在粘土介质中的电化学腐蚀行为。通过X射线衍射和碳氢氮光谱分析表征腐蚀产物的形成。通过扫描电子显微镜 (SEM) 研究表征暴露后 MS 和 GI 的表面形态。结果证明黏土中的GI受到腐蚀的严重影响。究其原因，可能是由于锌层厚度不够，以及微生物的存在，加剧了GI腐蚀。通过X射线衍射和碳氢氮光谱分析表征腐蚀产物的形成。通过扫描电子显微镜 (SEM) 研究表征暴露后 MS 和 GI 的表面形态。结果证明黏土中的GI受到腐蚀的严重影响。究其原因，可能是由于锌层厚度不够，以及微生物的存在，加剧了GI腐蚀。通过X射线衍射和碳氢氮光谱分析表征腐蚀产物的形成。通过扫描电子显微镜 (SEM) 研究表征暴露后 MS 和 GI 的表面形态。结果证明黏土中的GI受到腐蚀的严重影响。究其原因，可能是由于锌层厚度不够，以及微生物的存在，加剧了GI腐蚀。