About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
High Temperature Creep Properties of Advanced Structural Materials
|
Presentation Title |
Threshold Creep Behaviour of Ni-based Superalloy IN740H |
Author(s) |
Chandan Kumar, Pavan A.H.V., Praveen Kumar |
On-Site Speaker (Planned) |
Praveen Kumar |
Abstract Scope |
Creep deformation of nickel-based superalloy IN740H was studied at temperatures of 750 and 800 °C. The samples were aged at 800 °C after solution-treatment from 4 to ~10,000 h. The tests were performed in compression at a stress in the range of 200 to 450 MPa. The apparent stress exponent, n, changed from 4.5 at 800 °C to 10 at 750 °C. However, effect of prior aging was not observed on the stress exponent. The apparent activation energy, Qc, was calculated to be 565 kJ/mol. The high values of apparent n at 750 °C and Qc suggest a threshold behaviour, i.e., a critical stress value below which creep would not occur. By applying the concept of threshold stress, the true stress exponent and activation energy were calculated to be 4 and 298 kJ/mol, respectively. Subsequently, structure-property correlation was established using transmission electron microscopy and atom probe tomography. |
Proceedings Inclusion? |
Planned: |
Keywords |
Mechanical Properties, High-Temperature Materials, Other |