目的 探究石墨烯基防护涂层/碳钢体系在原油储罐沉积水中的防护机制。方法 以实际原油储罐的沉积水为腐蚀介质，以自制石墨烯底漆和石墨烯面漆为防护涂层体系，采用交流阻抗谱、动电位极化曲线，结合盐雾实验探究石墨烯涂层体系在沉积水中的腐蚀行为和失效衍化机制。结果 石墨烯底漆在浸泡初期对碳钢具有一定的防护效果，随着浸泡时间的延长，水分子逐渐渗透涂层，涂层逐渐失效。采用石墨烯面漆和石墨烯底漆搭配，可显著提高涂层对碳钢在沉积水中的防护性能，浸泡46 d后，涂层电阻仍为162 MΩ?cm。结论 石墨烯底漆和石墨烯面漆涂层体系对储罐底板在沉积水中具有良好的防护性能，研究成果对油罐底板涂层防护选材具有理论指导意义。

The work aims to explore protective mechanism of grapheme-based protective coating/carbon steel system in sedimentary water of crude oil storage tank. With the sedimentary water of actual oil storage as corrosive medium, and self-made graphene primer and graphene finish paint as protective coating system, electrochemical impedance spectroscopy, potentiodynamic polarization curves in combination with salt spray test were used to investigate corrosion behavior and failure derivation mechanism of graphene coating system in sedimentary water. The graphene primer had certain protective effect on carbon steel in initial period of soaking. Water molecules penetrated into the coating gradually and the coating failed gradually as the soaking duration prolonged. The protective effect of the coating on the carbon steel in the sedimentary water could be significantly improved by the combination of the graphene primer and graphene finish paint. After 46 days of soaking, the coating resistance of graphene composite coating was still 162 MΩ?cm. The graphene primer + graphene finish paint coating system has excellent protective effect on oil tank baseplate in the sedimentary water. The study results have theoretical guiding significance on coating material selection of oil tank baseplate.