Annealing Process of Stainless Steel

Annealing is a kind of heat treatment process for materials, which refers to slowly heating the metal to a certain temperature, and then cooling it at an appropriate rate after a certain time. Its advantage is to reduce hardness and improve machinability; Eliminate residual stress, stabilize size, reduce deformation and crack tendency; Refine the grain, adjust the structure and eliminate the structural defects.

The annealing process of stainless steel is mainly divided into three types: complete annealing, spheroidizing annealing and stress relief annealing.

1. Complete annealing. Heat the stainless steel for a period of time to make its internal structure completely austenitized. After holding it at 30~50 ℃ for a period of time, cool it with room temperature.
2. Spheroidizing annealing. When the stainless steel is heated to the beginning of forming austenite, it shall be kept at 20~40 ℃ for a period of time, and then slowly cooled. During cooling, lamellar cementite in pearlite inside it will become spherical.
3. Evenly arrange the stainless steel belt on the feeding frame, wait for the conveyor belt to send it to the annealing furnace, heat it to 1050~1080 ℃ under the protection of a controlled atmosphere, and then keep it warm for a short period of time until the carbide precipitated from austenite is completely dissolved in the austenite structure, and quickly cool it to below 350 ℃.