What type of corrosion specifically attacks the grain boundary of metal?

Intergranular corrosion specifically targets the grain boundaries of metals. This type of corrosion occurs when the areas at the grain boundaries become less stable compared to the rest of the metal. This instability can be due to various factors, such as the presence of impurities or the effects of heat treatment.

In intergranular corrosion, the corrosion process preferentially attacks these grain boundaries, which can lead to significant degradation of the material without affecting the bulk of the metal. This makes it particularly insidious, as it can severely weaken the material while appearing relatively intact on the surface.

Pitting corrosion, on the other hand, creates small, localized pits on the surface, whereas galvanic corrosion involves the electrochemical reaction between two different metals in an electrolyte. Uniform corrosion affects the entire surface of a metal evenly, leading to a more uniform loss of material rather than targeting specific areas like the grain boundaries.