About this Abstract |
Meeting |
Superalloys 2021
|
Symposium
|
Superalloys 2021
|
Presentation Title |
Stress-induced Variant Selection of γ″ Phase in Inconel 718 during Service: Mechanism and Effects on Mechanical Behavior |
Author(s) |
Hailong Qin, Zhongnan Bi, Ruiyao Zhang, Tung-Lik Lee, Hongyao Yu, Hongbiao Dong, Jinhui Du, Ji Zhang |
On-Site Speaker (Planned) |
Hailong Qin |
Abstract Scope |
The stress-induced variant selection (SIVS) of ã″ phase caused by thermo-mechanical coupling condition is studied systematically. The SIVS index f is devised and utilized to quantify the degree of SIVS via SEM image post-processing within <001> oriented grains. Applied stress condition does not affect the volume fraction, average size and crystallographic orientation of the ã″, but changes the proportion of the three variants. The SIVS behavior of ã″ phase is dependent upon the applied stress direction and grain orientation. By considering the variation of the SIVS index with thermal aging and creep parameters, a causal relationship between degree of SIVS with temperature, stress, and time is elucidated. The yield strength and tensile strength at 650°C decreases with the increase of SIVS degree. Contour map for the degree of SIVS is presented to evaluate the service temperature and stress of an Inconel 718 component. The formation mechanism of SIVS of ã" is proposed: the orienting effect of stress conditon is appreciable only during Ostwald ripening, due to the change of the ã″/ã lattice mismatch. |
Proceedings Inclusion? |
Undecided |