大型原油储罐底板腐蚀是影响和决定油罐服役寿命的关键问题。原油本身并不具备强腐蚀性，油品在开采过程中常夹杂一定水和腐蚀性介质，在长期存储过程中“水沉油浮”，腐蚀性沉积水在油罐底部聚集，使罐底长期处于沉积水浸没状态。沉积水成分复杂，含有大量氯离子、硫酸盐和厌氧微生物，这些介质使油罐罐底处于强腐蚀环境，对油罐底板产生持续腐蚀。同时，浮顶油罐立柱的冲击和振动、液体紊流和原油压力会加速油罐底板腐蚀失效。详细探讨了油罐罐底的腐蚀机理和失效衍化机制，分析罐底在沉积水环境中的腐蚀形式，包括电化学腐蚀、冲刷腐蚀、堆积腐蚀、微生物腐蚀以及焊缝腐蚀等，介绍了环氧类、聚氨酯类、富锌底漆类、氟碳类等重防腐涂层的发展现状，分析了油罐防护所采用的重防腐涂料技术，提出了油罐底板防护的未来研究方向。

Caseplate corrosion is a key issue affecting and determining service life of large-scale crude oil storage tank. Crude oil itself is noncorrosive, however, water and certain corrosive medium are usually mixed up with oils during exploitation process. “Water sinks and oil floats” during long-term storage, corrosive sedimentary water deposits on the bottom of oil tank, hence the tank bottom has been immersing in sedimentary water for a long term. Chemical composition of the sedimentary water is complex, which contains plenty of chloride, sulfate and anaerobic microorganisms. The mediums expose the oil tank bottom to strong corrosive environment and cause continuous corrosion to oil tank baseplate. Meanwhile, shock and vibration of the floating roof tank column, liquid turbulence and crude oil pressure will accelerate corrosion failure of oil tank baseplate. Corrosion mechanism and failure derivation mechanism of the oil tank bottom were discussed in detail; corrosion forms of tank bottom in sedimentary water environment were analyzed, including electrochemical corrosion, erosion corrosion, stack corrosion, microbial corrosion and weld corrosion; development status of heavy-duty anti-corrosive coating was introduced, including epoxy, polyurethane, zinc rich primer, fluorocarbon coatings; heavy-duty anti-corrosive coating technologies adopted by oil tank protection were analyzed; finally future research directions of oil tank baseplate protection was presented.