|About this Abstract
|10th International Symposium on Superalloy 718 and Derivatives (2023)
|Superalloy 718 and Derivatives
|Effect of Pre-straining on the Tensile and Stress-rupture Properties of a Novel Ni-Co Based Superalloy
|Bin Gan, Zhongnan Bi, Cheng Yang, Hongyao Yu, Rui Hu, Jinhui Du
|On-Site Speaker (Planned)
Ni-base superalloys are well suited for aero engine and power generation system, as they possess an extraordinary combination of excellent high temperature mechanical properties, a long-term structural integrity and microstructural stability, and robustness to surface degradation in highly corrosive and oxidizing environment. For most Ni-base superalloys, high strength is mainly derived from precipitation hardening by intermetallic compounds. While the recent development of Ni-Co based superalloys demonstrates that with the addition of Co content, the stacking fault energy could be effectively reduced that will assist the formation of microtwins or nanotwins. In the present study, a Ni-Co based superalloy with a chemistry of Ni-20.0Co-16.5Cr-5.0W-2.5Al-2.5Ti-2.5Nb-0.02C (wt.%) was produced by a vacuum induction melting and electro slag remelting. The cast ingot was homogenized and then forged into a rod with a diameter of 150 mm. The rod was solution treated at 1080 °C for 4 h followed by water quenching to room temperature. The influences of pre-straining temperature and pre-straining amount on the tensile properties of Ni-Co based superalloy at different temperatures as well as the stress-rupture properties at elevated temperatures were investigated. Dislocations are commonly formed at room temperature, while stacking faults and microtwins or nanotwins could be formed at elevated temperatures. The tensile testing results reveal that the application of pre-straining could effectively increase the yield strength of Ni-Co based superalloys while retaining a decent level of stress-rupture properties. The assimilated body of knowledge will give insight to the further alloy development for the fastener applications.
|Definite: At-meeting proceedings