When in history do we first have record of steel being used as a material? I am also interested in both its initial purpose and when it was first used in weapon making.
According to wikipedia:
The earliest known production of steel is a piece of ironware excavated from an archaeological site in Anatolia (Kaman-Kalehoyuk) 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 (403–221 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. The Haya people of East Africa discovered a type of high-heat blast furnace which allowed them to forge carbon steel at 1,802 °C (3,276 °F) nearly 2,000 years ago. This ability was not duplicated until centuries later in Europe during the Industrial Revolution.
According to wikipedia, Steel has been around since antiquity, but reference to steel weapons can be found in 4th century BC Ibernia, Romans, and in Chinese references during their Warring States era.
The steel that we think of today was originally made East Africa by the Haya people over two eons ago, but wouldn't be rediscovered until the Industrial revolution. Before then, what we think of that makes the weapons and buildings that we see didn't' really exist.