Rolled steel is the conversion of raw steel ingots from blast furnaces to different types of commercial profiles.
There are two types of steel rolling processes. Hot rolled and cold rolled:
The hot rolling process consists of preheating the raw steel ingots to a temperature that allows the deformation of the ingots by means of pressure cylinders called a rolling mill.
Hot steel that is above the recrystallization temperature can be shaped much more easily than cooler steel, and can be made from much larger sized ingots of material.
Cold rolled steel is produced by means of a forming process at room temperature, allowing its recrystallization. As a consequence of the manufacture of the steel at a much lower temperature, changes in volume and shape do not affect it, as they do in hot rolled steel. This is suitable for uses where precise shapes and low tolerances are not required.
This is the main reason why cold rolling is usually more expensive than hot rolling.
Rolled steel is used mainly in construction projects, from this process different shapes or presentations are obtained that serve to support the structures that in turn will have to resist the weight of other materials to be used.