Q: Can dissimilar (also called galvanic) corrosion occurs between Inconel bolts and regular carbon steel?
A: Anytime you have dissimilar materials you have the potential for galvanic corrosion. For this to happen the materials need to be wet or in some kind of solution. If they are dry it’s greatly reduced although humidity could be enough to cause the materials to galvanically couple.
Also whenever you have dissimilar materials you always want the part with less mass, in the case the bolts, to be the more noble alloy. Because the carbon steel plate has much more mass than the screw its affects will be greatly minimized. This is important as you don’t want to corrode the threads of the bolts.