Selection of cooling conditions for hardening large forgings in cooling installations

1. The suggested cooling regime for shaft forgings with 800-mm diameter in an air cooling installation ensures the same cooling rate of the point of the shaft with highest thermal inertia as in quenching in water and then in oil by immersion in quenching tanks. 2. Differentiated cooling of forging with variable cross section (diameter of the body 800 mm, of the journal 400 mm) in the cooling installation ensures more uniform cooling in quenching. The maximum temperature gradient between the centers of the journal and the body is 100°C.