Metal, ha. Try concrete, that blunts chain really fast.
I actually met a guy that "saved" a tree I took down once by filling it with concrete. It didn't work.
They do make such a saw but it spins much slower than an abrasive, about half the rpm and half again as much HP.The right kind of carbide should work, especially in a full house (cutter per DL) design, and patience letting the saw do the work at whatever pace it wants. They make non abrasive metal chop saws that have a carbide tipped blade, looks just like a circular saw blade used for wood, but has a lot more teeth, and it can easily cut through steel hundreds of times.