Response to Hot Deformation Conditions and Microstructure Development of Nimonic 80A Superalloy

Abstract

Laboratory compression tests at different temperatures and strain rates have been performed on Nimonic 80A superalloy to define optimal hot forming characteristics. A mathematical expression connecting mean grain size and true stress is presented using a Hall–Petch-like equation. The evolution of microstructure at various sample positions in correlation with deformation temperatures, strain, and strain rates has also been investigated. Optimal hot-working conditions are determined using processing maps and obtained microstucture.

Keywords:

• Activation energy
• Compression tests
• Dynamic material model
• Dynamic recrystallization (DRX)
• Hall–Petch-like relationship
• Hot deformation
• Metallography
• Nickel superalloy
• Nimonic 80A
• Optical microscopy
• Precipitates
• Processing maps
• SAD pattern
• TEM
• Zener–Hollomon