Is it necessary for a dissimilar metal to be connected to a cable for corrosion to occur on that underground cable?

Corrosion is a complex electrochemical process that can occur under various conditions and does not solely rely on the presence of dissimilar metals. The main factor in the corrosion of an underground cable is the presence of moisture, soil composition, and other environmental factors that can lead to the deterioration of metals.

Even if a cable is composed of similar metals or a single metal type, it can still corrode over time, particularly if there is moisture, electrolytic properties of the surrounding soil, and other corrosive elements. In the absence of dissimilar metals, other mechanisms such as pitting corrosion or galvanic corrosion can still occur due to the environmental influences on the metal.

The presence of dissimilar metals often accelerates corrosion due to galvanic reactions when two different metals are electrically connected and exposed to an electrolyte, but it is not a requirement for corrosion to take place. Thus, it is clear that corrosion can occur independently of having dissimilar metals associated with underground cables.