What are the key steps in the heat treatment process of 6061 aluminum alloy forgings?

The key steps in the heat treatment process of 6061 aluminum alloy forgings include:

Preheating: Forgings need to be preheated before heating to prevent cracks during heating. The preheating temperature is generally 100 ~ 200℃, and the holding time is 1 ~ 2 hours.

Heating: the forging is heated in the heating furnace, the heating temperature is 530 ~ 570℃, and the holding time is 2 ~ 4 hours. In the heating process, it should be avoided to heat too fast to prevent cracks in the forging.

Heat preservation: Keep the forgings at the heat preservation temperature for a certain time so that the temperature inside and outside the forgings is evenly distributed. The holding temperature is 550 ~ 570℃, and the holding time is 2 ~ 4 hours.

Air cooling: the heated forging is removed from the heating furnace and cooled in the air. The air cooling time is generally 4 to 6 hours.

Cooling post-treatment: The forging needs to be treated after cooling to remove the stress inside the forging and improve the strength and stability of the forging. Treatment methods include straightening, stress relief annealing, etc.

It should be noted that parameters such as temperature and time in the heat treatment process need to be determined according to the specific situation of the forging, and it is necessary to properly protect the forging during the heat treatment process to prevent problems such as oxidation and corrosion of the forging.