缝隙腐蚀指在缝隙内发生的腐蚀。常发生在密封件下面，螺母、铆钉头附近或未完全焊透的焊缝等液体流动困难的区域。

在缝隙中，液体的流动被阻挡，溶解氧被迅速的耗尽。几秒钟之内就可以在脱气的小空间和暴露于空气的表面之间形成一个浓差电池。缝隙中介质的酸度逐渐增加。

Crevice corrosion refers to corrosion occurring in confined spaces to which the access of the working fluid from the environment is limited. These spaces are generally called crevices. Examples of crevices are gaps and contact areas between parts, under gaskets or seals, inside cracks and seams, spaces filled with deposits and under sludge piles.