The ability to produce, refine, and shape metal has been a key factor in humanity’s technological development. Though the basic principles have remained the same, our society’s metal manufacturing capabilities far exceed those of our ancestors.
Steel begins as naturally occurring iron ore. A blast furnace, and a few key ingredients, is used to turn the iron ore into pig iron. Then, pig iron is refined using either a basic oxygen furnace or electric arc furnace. These furnaces create molten iron, which is then cooled in molds to create solid ingots. Or the hot iron is passed through a continuous caster to produce a solid slab of steel.
Steel pieces are then hot worked and cold worked. Hot working can shape steel into billets, blooms, and slabs, while cold working shapes the steel by increasing dimensional accuracy and the finish of the surface. Pickling, annealing, and carburizing also help refine steel into a more usable material.