HOT FORMED STEEL


Hot Formed Steel Sections


Hot formed steel sections refer to end products which were formed at a temperature higher than the steel's recrystallization temperature. A solid piece of steel (like billets, blooms or slabs) is heated to a temperature higher than its recrystallization temperature. It is then send through sets of dies or rolls, known as passes, forming the billet, bloom or slab to the required form. After the section is formed it is left to cool down, during which it will recrystallize. One major advantage of hot forming a steel section rather than to cold form it, is that the force required is much lower.

Hot formed sections include I-beams, equal and unequal flanged channels, cross-sections, etc. The following are a few advantages and disadvantages of hot formed sections, in comparison with cold formed sections:

Advantages:

  • Ductility is increased.
  • The yield strength is reduced.
  • Large deformation can be repeated.
  • The chemical inhomogeneities can be removed or decreased by the higher temperatures.

Disadvantages:

  • Accuracy of the dimensions is lower than cold formed steel.
  • The quality of the surface finish of the end product is lower.
  • The fact that the parts need to be heated is a disadvantage because a unit is required for the heating.
  • The tolerances are not as precise as with cold formed sections.
  • Hardness is lower than that of cold formed steel sections.