Annealing of bed castings

Annealing types of heat treatment: Common annealing processes include: recrystallization annealing, stress relief annealing, spheroidizing annealing, complete annealing, etc. The purpose of annealing: mainly to reduce the hardness of metal materials, improve plasticity, facilitate cutting or pressure processing, reduce residual stress, improve the homogenization of organization and composition, or prepare the organization for subsequent heat treatment.

Complete annealing and isothermal annealing

Complete annealing is also called recrystallization annealing, generally referred to as annealing. This annealing is mainly used for castings, forgings and hot-rolled profiles of various carbon steels and alloy steels with hypoeutectoid components, and sometimes for welded structures. It is usually used as the final heat treatment of some non-heavy workpieces, or as a pre-heat treatment of some workpieces.

Spheroidizing annealing

Spheroidizing annealing is mainly used for hypereutectoid carbon steel and alloy tool steel (such as steel used to make cutting tools, measuring tools, and molds). Its main purpose is to reduce hardness, improve cutting processability, and prepare for subsequent quenching.

Stress relief annealing

Stress relief annealing is also called low temperature annealing (or high temperature tempering). This annealing is mainly used to eliminate residual stress in castings, forgings, welded parts, hot rolled parts, cold drawn parts, etc. If these stresses are not eliminated, they will cause deformation or cracks in the steel parts after a certain period of time or in the subsequent cutting process.