Thermal Deformation and Dynamic Recrystallization Behavior of Superalloy Billet during Forging
The main effects of strain,deformation temperature,strain rate,ingot homogenization level and second phase distribution on the hot deformation and dynamic recrystallization behavior of superalloy billet during forging process were studied.The engineering application experience of the conditions for obtaining fully dynamic recrystallization microstructure of superalloy billet was introduced.The incomplete dynamic recrystallization structure of superalloy billet leads to serious noise in ultrasonic testing,which leads to the hidden inclusion cluster defects in the billet covered by noise signals,and brings the risk of premature fatigue failure to the service of materials.The strain,deformation temperature and strain rate conditions of complete dynamic recrystallization of superalloy billet are subject to the performance of forging equipment.The homogenization level and the second phase distribution of the alloy depend on the material properties and the design of process parameters.The engineering way to achieve complete dynamic recrystallization of superalloy billet is multiple upsetting+stretching and billeting by fast forging machine,and forging forming by radial forging machine at the end of the fire.