Welding Cast Iron in Carbon Steel

Centuries ago, Japanese and Syrian weapons-smiths would forge-weld a piece of iron to a piece of steel, then beat in out thin, fold and re-weld, and beat again, over and over, sometimes hundreds of times, shaping them into the legendary swords of Damascus and Japan. I have speculated that Excalibur may well have been a sword made in such fashion, unknown in Britain of that era, for such a weapon would have seemed magical in the hands of an English knight.

Anyway, the point is that it is quite possible to weld iron to steel, though I understand that cast iron does present some unique difficulties.