On 2018-08-08 14:48:54
Homogenization annealing of heat treatment process
In the heat treatment process, the purpose of annealing is to reduce the hardness and improve the plasticity of the steel, so as to facilitate the cutting and cold deformation processing. Therefore, we usually use homogenization annealing to continue the screwing treatment during the processing. Let's see next.
1. Homogenization annealing is an annealing process to reduce the segregation of chemical composition and the inhomogeneity of structure of metal ingot, casting or forging billet, heat it to high temperature, keep it for a long time, and then cool it slowly for the purpose of homogenization of chemical composition and structure.
2. The heating temperature of homogenization annealing is generally AC3, i.e. 1050 ~ 1150 ℃, and the holding time is generally 10 ~ 15h, so as to ensure that the diffusion is fully carried out and to eliminate or reduce the uneven composition or structure in large quantities.
3. Because of the high heating temperature, long time and coarse grains in diffusion annealing, complete annealing or normalizing can be carried out after diffusion annealing to refine the structure again.
After heat treatment and homogenization annealing, the hypoeutectoid steel is ferrite and pearlite, which is close to equilibrium. So in the actual production, we need to pay more attention to these problems.