中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 26 No. 1 January 2016 |
（1. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
2. Light Alloy Research Institute, Central South University, Changsha 410083, China;
3. State Key Laboratory of High Performance Complex Manufacturing,
Central South University,Changsha 410083, China;
4. Key Laboratory of Efficient and Clean Energy Utilization,School of Energy and Power Engineering,
Changsha University of Science and Technology, Changsha 410114, China）
Abstract:Effects of initial δ phase (Ni3Nb) on the hot tensile deformation behaviors and material constants of a Ni-based superalloy were investigated over wide ranges of strain rate and deformation temperature. It is found that the true stress-true strain curves exhibit peak stress at a small strain, and the peak stress increases with the increase of initial δ phase. After the peak stress, initial δ phase promotes the dynamic softening behaviors, resulting in the decreased flow stress. An improved Arrhenius constitutive model is proposed to consider the synthetical effects of initial δ phase, deformation temperature, strain rate, and strain on hot deformation behaviors. In the improved model, material constants are expressed as the functions of the content of initial δ phase and strain. A good agreement between the predicted and measured results indicates that the improved Arrhenius constitutive model can well describe hot deformation behaviors of the studied Ni-based superalloy.
Key words: Ni-based superalloy; hot deformation; initial δ phase; constitutive model; material constants
