Uncomplete annealing is suitable for hypoeutectoid steel as well as hypereutectoid steel. Its characteristic is that the cementite in the pearlite becomes spherical after annealing, and this type of uncomplete annealing is also known as spheroidizing annealing.
For hypoeutectoid steel, incomplete annealing is often due to the following circumstances:
(1) Enhance the cutting performance of these heat treatments, primarily used for forged structural components, especially those with high carbon content. These components are difficult to machine due to the excessively fine pearlite and high hardness after forging.
(2) Spheroidal decarburization for improved cold deformation properties, used for hypoeutectoid steels requiring cold working deformation.
