Grain refinement can strengthen the mechanical properties of materials according to the classical Hall-Petch relationship but does not always result in better corrosion resistance. During the past few decades, various techniques have been dedicated to refining grain, along with relevant studies on corrosion behavior, including general corrosion, pitting corrosion, and stress corrosion cracking. However, the fundamental consensus on how grain size influences corrosion behavior has not been reached. This paper reviews existing literature on the beneficial and detrimental effects of grain refinement on corrosion behavior. Moreover, the effects of microstructural changes (i.e., grain boundary, dislocation, texture, residual stress, impurities, and second phase) resulting from grain refinement on corrosion behavior are discussed. The grain refinement not only has an impact on the corrosion performance, but also results in microstructural changes that have a non-negligible effect on corrosion behavior or even outweigh that of grain refinement. Grain size is not the only factor affecting the corrosion behavior of metallic materials; thus, the overall influence of microstructures on corrosion behavior should be understood.

根据经典的 Hall-Petch 关系，晶粒细化可以增强材料的机械性能，但并不总是能带来更好的耐腐蚀性。在过去的几十年中，各种技术致力于细化晶粒，以及对腐蚀行为的相关研究，包括全面腐蚀、点蚀和应力腐蚀开裂。然而，尚未就晶粒尺寸如何影响腐蚀行为达成基本共识。本文回顾了有关晶粒细化对腐蚀行为的有益和有害影响的现有文献。此外，还讨论了晶粒细化导致的微观结构变化（即晶界、位错、织构、残余应力、杂质和第二相）对腐蚀行为的影响。晶粒细化不仅对腐蚀性能有影响，而且会导致微观结构变化，这些变化对腐蚀行为具有不可忽略的影响，甚至超过晶粒细化的影响。晶粒尺寸并不是影响金属材料腐蚀行为的唯一因素；因此，应了解微观结构对腐蚀行为的整体影响。