I'll confess that I have a real issue with iron--it rusts quickly. In fact, the History Channel program Life After People constantly states that, left to its own devices, the iron that makes up a skyscraper's skeleton would have a standing lifespan of 100-150 years before rust weakens the skeleton into pieces.
Long ago, I asked a question regarding the construction of metal weapons without the use of iron at all. In the answers selection, many candidates have been suggested, and they are:
- Titanium Alumnide
- Nickel Superalloy
- Nickel Alumnide
- Tungsten Carbide
- Zirconium Carbide
- An alloy of Titanium and Tungsten
What makes this list relevant to the question is that steel or any other kind of alloy had been used to make weapons before their use in construction, so the principle would be identical.
In an alternate, cyber-or-steam-punk New York, Chicago, Dallas or any of the United States' biggest cities, these listed metals and alloys had been considered for construction of mega-towers (a little like this or this or, if you want to go more historical, the artworks of Hugh Ferriss.) Using the science involved, which of the listed metals would be strongest in regards to tension, compression and resistance to corrosion?
Oh, and before anyone asks, this question stresses on quality, not quantity.