Graphite is normally very soft and slippery, and is even able to act as a dry lubricant when finely powdered, however many sources claim that graphite powder can be highly abrasive, to the point of potentially destroying milling machines. Does anyone know how such a soft material can abrade metals?
I don’t see how graphite could induce galvanic corrosion. It’s a good electrical conductor, not so much for ions (larger than lithium). And the metal itself is already electrically conductive. The only possibility I could think of is spontaneous oxidation from the air, but it’s stable to a few thousand °C so… this isn’t adding up. You can even use graphite crucibles for metallurgy.