45 Normalizing

Normalizing, like annealing, is also a process for making material softer but does not produce the uniform material properties of annealing. A material can be normalized by heating it to a specific temperature and then letting it cool to room temperature outside of the oven. This process is less expensive than annealing because the oven can be used for something else while the part is cooling down on the outside of the oven. However, keep in mind that cooling down in ambient air is a lot like quenching in a liquid bath and may produce like results. (see quench tempering)

Normalization is an annealing process applied to ferrous alloys to give the material a uniform fine-grained structure and to avoid excess softening in steel. It involves heating the steel to 20–50 °C above its upper critical point, soaking it for a short period at that temperature and then allowing it to cool in air. Heating the steel just above its upper critical point creates austenitic grains (much smaller than the previous ferritic grains), which during cooling, form new ferritic grains with a further refined grain size. The process produces a tougher, more ductile material, and eliminates columnar grains and dendritic segregation that sometimes occurs during casting. Normalizing improves machinability of a component and provides dimensional stability if subjected to further heat treatment processes.

Step 3: Hot metal removed from oven Source: The Virtual Machine Shop (2011) CC BY-SA 4.0

Derived from Annealing (materials science) – Wikipedia accessed and available 11 December 2024 and The Virtual Machine Shop retrieved from the Wayback Machine (http://www.jjjtrain.com/vms/eng_heat_treat/eng_heat_treat_03.html) 17 January 2024.