Heat Treatment is the controlled heating and cooling of metals to alter their physical and mechanical properties without changing the product shape. Heat treatment is sometimes done inadvertently due to manufacturing processes that either heat or cool the metal such as welding or forming. Heat Treatment is often associated with increasing the strength of material, but it can also be used to alter certain manufacturability objectives such as improve machining, improve formability, restore ductility after a cold working operation. Thus it is a very enabling manufacturing process that can not only help other manufacturing process, but can also improve product performance by increasing strength or other desirable characteristics.
Normalizing is a process of heating steel to about 40 to 50 degree above upper critical temperature,holding for proper time,and then cooling in still air or at room temperature.
In this treatment,steel is heated to a temperature below the lower critical temperature,and is held at this temperature for sufficient time and then cooled.
Practically all steels,which have been heavily cold worked,are subjected to this treatment.The process consists of heating steel above the recrystallization temperature and cooling thereafter.
Partial annealing is also referred to as interstitial annealing or incomplete annealing.In this process,steel is heated between the lower critical temperature and the upper critical temperature.
The process,also known as homogenizing annealing,is employed to remove any structural non uniformity.In diffusion annealing treatment,steel is heated sufficiently above the upper critical ...
In this process,hypoeutectoid steel is heated above the upper critical temperature and held for some time at this temperature.This is done in order to get a completely austenitic structure and to ...
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