To be fair, steel is iron. The difference between raw iron and steel is that carbon or some other element has been added to the iron during the smelting process in order to strengthen it. The term "Carbon Steel" means that the iron to carbon ratio is ~ 99% iron/1% carbon (+/- ~1%). Stainless steel is ~89/11% alloy of iron and chromium. Stainless steel is resistant to oxidation (it doesn't rust as quickly or easily), hence the name. Other hardening elements include manganese, vanadium and tungsten.
That said, in 2072 (or even in the 2050's) there are a lot of materials available that are better than carbon steel. Titanium-steel alloys for one, or alloys that use tungsten. There are also ceramics that rival or surpass some metals and have the added advantage of being hard to detect when you pass through a MAD or some other form of metal detector.
The way I handle it in my house game is if the description of the item doesn't specify, then the player can pick what grade of material they want. If they choose something like the ceramic that would give an added in-game benefit, I up the price and availability ratings.