1. Complete annealing and isothermal annealing, complete annealing and weighing crystallization annealing are generally referred to as annealing, which is mainly used for casting, forging and hot rolling sections of various carbon and alloy steels with hypoeutectoid composition, and sometimes for welding structures. Generally, it is used as the final heat treatment of some unimportant workpieces or as the pre heat treatment of some workpieces.
2. Spheroidizing annealing spheroidizing annealing is mainly used for hypereutectoid carbon steel and alloy tool steel (such as the steel used for manufacturing cutting tools, measuring tools and dies). Its main purpose is to reduce hardness, improve machinability, and prepare for later quenching
3. Stress relief annealing, also known as low temperature annealing (or high temperature tempering), is mainly used to eliminate the residual stress of castings, forgings, weldments, hot rolled parts, cold drawn parts, etc. If these stresses are not eliminated, it will cause deformation or cracks in the steel after a certain period of time or in the subsequent cutting process.