Steel was known in antiquity, and may have been produced by managing bloomeries iron-smelting facilities so that the bloom contained carbon.
The earliest known production of steel is a piece of ironware excavated from an archaeological site in Anatolia (Kaman-Kalehoyuk ){modern day Turkey} and is about 4,000 years old. Other ancient steel comes from East Africa, dating back to 1400 BC.
In the 4th century BC steel weapons like the Falcata were produced in the Iberian Peninsula, while Noric steel was used by the Roman military.
The Chinese of the Warring States (403221 BC) had quench-hardened steel, while Chinese of the Han Dynasty (202 BC 220 AD) created steel by melting together wrought iron with cast iron, gaining an ultimate product of a carbon-intermediate steel by the 1st century AD.
http://en.wikipedia.org/wiki/Steel
Although there is much debate about the BoM references to steel. I suppose it all depends on how one interprets the use of the word “steel”. Wiki here describes it more like iron vs. steel.
As far as interpreting "steel" my experience with lds is that whatever they say at the moment is the interpretation.