Annealing is a metal heat treatment process, which refers to the metal is slowly heated to a certain temperature, held for a sufficient time, and then cooled at a suitable speed. The purpose is to reduce the hardness and improve the machinability; Eliminate residual stress, stabilize size, reduce deformation and crack tendency; Refine grain, adjust structure, eliminate structure defects.
To be exact, annealing is a heat treatment process for materials, including metal materials and non-metallic materials.
Moreover, there are similarities and differences between the annealing purpose of the new material and the traditional metal annealing.
Main feature:
It is to soften the material or workpiece after casting, forging, welding or cutting, improve plasticity and toughness, homogenize the chemical composition, remove residual stress, or get the expected physical properties.
There are many kinds of annealing processes depending on the purpose, such as isothermal annealing, homogenizing annealing, spheroidizing annealing, stress removal annealing, recrystallization annealing, stabilization annealing, magnetic field annealing and so on.
1. Metal tools lose their original hardness when used by heat.
2. The metal material or workpiece is heated to a certain temperature and continues for a certain time, so that the slow cooling.
Annealing can reduce the hardness and brittleness of the metal and increase the plasticity.
Aim:
1. Reduce hardness and improve machinability.
2. Eliminate residual stress, stabilize size, reduce deformation and crack tendency.
3. Refine the grain, adjust the structure, and eliminate the defects of the structure.
4. Uniform material structure and composition, improve material properties or prepare the organization for later heat treatment.
In production, annealing process is widely used. According to the purpose of the workpiece requirements of annealing, there are many kinds of annealing process specifications, commonly used are complete annealing, spheroidizing annealing, and stress relief annealing.
