Steel is not a natural element that is found in its pure state in nature. It is an alloy of iron and carbon. It comes in many different grades (there are over 3500) with unique properties, finishes, shapes and specifications; this, with the aim of being used in all types of industries and infrastructures. He rolled steel, whether cold or hot, is very popular especially in the tube industry.

El laminated It is a process to which the steel is subjected in which it is introduced into rollers so that its thickness is reduced. The result is a more uniform piece. In this process, a laminate can be made in two types depending on its temperature: hot and cold.

In this article we will talk, precisely, about cold and hot rolled steel, how they are applied and what benefits and differences each has. Will you join us to learn a little more and delve into this interesting topic?

hot rolled steel

It is a steel that has been formed at a temperature close to 1000 degrees, specifically, more than 926. This temperature prevents recrystallization in order to give the shape that is needed. This process also implies a much cheaper production cost than that carried out cold, in addition to being carried out without pauses or delays. Thus, thanks to this modality, it is not necessary for the steel to be overheated.

To process the steel starts with a billet, that is, a large rectangular piece of metal. This is heated, flattened and turned into a roll. The final dimensions of the original billet are defined by rollers.

hot rolled steel - Ferros Texar

When this hot steel cools, it contracts, achieving less predictable shapes and sizes than if the cold process were carried out. On the one hand, this can be a disadvantage, although it is also quite the opposite, since it allows many different shapes with very high resistance.

How do you know that the rolled steel you are handling is hot?

  • For the rough surface what's wrong with it. This occurs because a little of the cooling process from high temperatures remained in the steel.
  • Slightly rounded edges. This is due to the shrinkage process when cooling and the less finish it has.
  • Distortions. This can be seen in trapezoidal angles instead of squares, for example.

As for applications, this type of steel is not used for jobs that require certain precision, but they are common for structural tasks such as construction, railways, etc.

Benefits of hot rolled steel

This type of rolled steel requires less processing than cold, something that makes it cheaper. The hardening processes mechanic They will not be so problematic, since the cooling that is carried out with this type of laminate is at room temperature.

Hot rolled steel also, having a higher tolerance, allows for greater moldability, while cold rolled steel is limited to some limited shapes such as flat, square and round.

cold rolled steel

Unlike hot steel, cold steel is formed at room temperature, which crystallizes. In this case, the change of volume and shape is not common, which is why it is normal for it to be used in jobs that require very precise sizes and shapes. These latter concepts anticipate a higher cost of cold rolling than hot rolling.

cold rolled steel - Ferros Texar blog

Among the characteristics that this laminate has is hardness, resistance and the almost impossibility of it deforming without breaking. It is necessary to submit to a annealing process to this steel.

How do you know what you are using is cold lamination? To distinguish cold rolling it is easy to detect some characteristics:

  • Better surfaces than those produced hot, with close tolerances.
  • smooth surfaces and greasy when touched.
  • Steel tubes have straightness and concentric uniformity.
  • The steel bars have the defined edges correctly and the angles well formed.
  • This laminate is used for jobs that require great precision.

cold benefits

El cold rolled steel is used for much more precise work than the hot one. Also, in those that require greater aesthetics. Of course, the production cost, as well as the sales price, are much higher than in the hot market.

Cold steel is more strong and resistant, since as it is shaped with a cold process the resistance against tension and deformation is greater.

Differences between both rolled steels

We have already seen throughout this article some basic differences between hot and cold rolling. These have to do with resistance, hardness, precision, roughness and edges, among others. We can also highlight differences in mechanical properties, which depend on the chemical composition or grade. In this aspect, there are notable differences between one and the other.

  • resistance to traction: Hot rolled is 67 psi, while cold rolled is 000.
  • Yield strength: the first, 45 psi; and the second, 000 psi.
  • Volumetric reduction: hot rolling, 58; the cold one, 55.
  • 2” stretch: 36 versus 28.
  • Brinell hardness: 137 versus 167.

Uses of both rolled steels

Both steels, in addition to having a different processing, also have, as we have briefly mentioned, varied uses. Here we leave you the most common ones.

Uses with hot steel:

  • Buildings metallic
  • Wheel
  • Anchors
  • Frames and other parts of some heavy vehicles
  • Train tracks
  • General structures in construction
  • Water heaters

Uses with cold steel:

  • chairs
  • Exhaust pipes
  • Tables
  • Water heaters
  • Shelving
  • Home Appliances
  • Cabinets
  • Metal furniture
  • Different parts of machinery

El rolled steel It is ideal for carrying out different types of work. The result of a hot and cold treatment is different. If you require the best quality steel, in Texar Ferros We have everything you need. Contact us and find out everything we can do for you!