What is normalizing? | Applications

What is the normalizing process?

Normalizing is a heat-treatment process. It is applied to ferrous materials. The objective of this process is to enhance the mechanical properties of the material by refining the microstructure.

In the normalizing process first of all, metal is heating it to a specific temperature and then letting the material cool to room temperature and the material can be normalized.

In the normalizing of steel, it is heated to slightly above its upper critical temperature and held for sufficient time to allow new smaller metal grains to form and high energy grain shapes to coalesce. This is known as grain refinement and it forms a more uniform metal product. 

Normalization is a type of heat treatment used to relieve stress thereby improving ductility and toughness. 

Normalizing Process is determined by 

  • The heating temperature of the metal (20° - 50° C above the critical upper point)
  • Holding Time  (Minimum time that is required to achieve uniform heating)
  • Cooling Rate (150°-250°C per hour)
Normalizing is performed on structures or the structural components that will be subjected to machining because it improves the machinability of carbon steels. This process is less expensive than annealing.

Applications of normalizing 

  • It is used in some plate mills in the production of large forging such as railroad wheels and axles and some bar products.
  • For sheet metal forming and also for brackets, normalization is used.
  • Used in stress relieve of castings.
  • For recovery, the original mechanical properties of forged or cold worked steel.