Hot Rolling Process

Hot Rolling Process:

In the working or rolling process known as "hot rolling," metal is heated above the recrystallization temperature in order to plastically distort it.

This process is used to create shapes with the desired geometrical dimensions and material properties while maintaining the same volume of metal. The hot metal is passed between two rolls to flatten it, lengthen it, reduce the cross-sectional area and obtain a uniform thickness.

Starting materials such as blooms or slabs at an elevated temperature flow from the continuous casting process directly into the rolling mills. In smaller operations the materials start at room temperature and must be heated either in a soaking pit, or by induction heating before being fed into the mill.

Hot-rolled steel is the most common product of the hot rolling process and is widely used in the metal industry either as an end product or as raw material for subsequent operations.

Hot rolling improves:

  • Toughness and strength
  • Ductility
  • Resistance to vibration and shock
  • Formability
  • Weldability

Hot-rolled steel products are classified into four groups:

  • Flat
  • Long
  • Seamless
  • Specialty

Typical applications of hot-rolled steel are:

  • Automotive structural parts such as frames
  • Tabular products such as pipe and gas cylinders
  • Machine structures such as saws and springs
  • Agriculture equipment
  • Metal buildings
  • Guard rails