The Titanic (and her sisters) and the Norwich City were both made with steel plating and framing, which had replaced iron in those applications by then. It was likely a similar kind of steel in both, as they were both built in Britain around the same time. There was also iron used in many places, such as cast iron in the engine. For this discussion, it doesn't make much difference, as the galvanic number of iron and low-carbon steel is the same (-85). The discussion here is whether galvanic corrosion could have hastened the disappearance of aluminum, which we can say it well might have, if in contact with ferrous metal, that is if Electra debris ended up in contact with Norwich City debris. Our reconstruction of events suggests that is possible. There are other possibilities, including (and not limited to) that it's somewhere we haven't looked, or buried underwater by fallen material (man-made and natural), or so broken up that we haven't recognized the pieces.
LTM,
Don