What is a risk of intergranular corrosion in metals?

Intergranular corrosion poses a serious risk as it can lead to a significant reduction in the strength of metals. This form of corrosion occurs along the grain boundaries of metals and alloys, where the microstructure is more susceptible to aggressive environments than the bulk of the material. When grain boundaries degrade, the integrity and load-bearing capacity of the entire component can be compromised, potentially leading to structural failure even if the surface appears unaffected.

Unlike uniform corrosion, which depletes material evenly across a surface, intergranular corrosion can progress rapidly on a localized scale without the same signs visible until it's too late. Furthermore, while it may not be easy to identify during inspection, the consequences—loss of strength and eventual crack propagation—can be severe, making it a critical consideration in materials selection and maintenance practices in maritime environments.