The Precipitation Behavior and Hot Deformation Characteristics of Electron Beam Smelted Inconel 740 Superalloy

Journal Article · Sun Apr 15 00:00:00 EDT 2018 · Journal of Materials Engineering and Performance

DOI:https://doi.org/10.1007/S11665-018-3193-1· OSTI ID:22860602

You, Xiaogang; Tan, Yi ^[1]; Wu, Chang ^[2]; You, Qifan; Zhao, Longhai; Li, Jiayan ^[1]

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1. Dalian University of Technology, School of Materials Science and Engineering (China)
2. University of Wollongong, Institute for Superconducting and Electronic Materials (Australia)

The Inconel 740 superalloy was prepared by the electron beam smelting (EBS) technology, the precipitation behavior and strengthening mechanism were studied, and the hot deformation characteristics of EBS 740 superalloy were investigated. The results indicate that the EBS 740 superalloy is mainly strengthened by the mechanism of weakly coupled dislocation shearing, and the resulting critical shear stress is calculated to be 234.6 MPa. The deformation parameters show a great influence on the flow behavior of EBS 740 superalloy. The strain rate sensitivity exponent increases with the increasing of deformation temperature, and the strain hardening exponent shows a decreasing trend with the increasing of strain. The activation energy of EBS 740 above 800 °C is measured to be 408.43 kJ/mol, which is higher than the 740H superalloy. A hyperbolic-sine-type relationship can be observed between the peak stress and Zener–Hollomon parameter. Nevertheless, the influence of deformation parameters is found to be considerably different at temperatures below and above 800 °C. The size of dynamic recrystallization (DRX) grains decreases with the increasing of strain rate when the strain rate is lower than 1/s, and reverse law can be found at higher strain rate. As a result, a piecewise function is established between the DRX grain size and hot working parameters.

• OSTI ID: 22860602
• Journal Information: Journal of Materials Engineering and Performance, Vol. 27, Issue 4; Other Information: Copyright (c) 2018 ASM International; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA); ISSN 1059-9495
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DEFORMATION
DISLOCATIONS
ELECTRON BEAMS
HEAT RESISTING ALLOYS
HOT WORKING
INCONEL ALLOYS
PRESSURE RANGE MEGA PA 100-1000
RECRYSTALLIZATION
STRAIN HARDENING
STRAIN RATE
STRAINS
STRESSES