About this Abstract |
Meeting |
2021 AWS Professional Program
|
Symposium
|
2021 AWS Professional Program
|
Presentation Title |
Microstructure and Mechanism Based Lifetime Predictions in Various Weldment Failures under Complex Thermomechanical Conditions |
Author(s) |
Zhili Feng, Yi Yang, Yanfei Gao, Jorge Penso |
On-Site Speaker (Planned) |
Zhili Feng |
Abstract Scope |
Stress relief cracking and various other high-temperature failures on or near weldments are a major issue dictating structural integrity and performance of many energy and power industries. Complex synergetic factors affect the generation and evolution of welding residual stress, such as post-weld heat treatment (PWHT), precipitation kinetics, or long-term service (ageing), which in turn controls the lifetime. Various mechanisms have been proposed in the past, but a direct and quantitative connection between laboratory tests and actual lifetime prediction is still lacking. Two critical issues are identified and addressed by our research team. First, a quantitative prediction of welding residual stress is very sensitive to the dynamic strain hardening behavior in the material constitutive law. Characterization of such a property and also non-destructive residual stress measurements by advanced diffraction techniques are needed along this line. Second, a microstructure-based lifetime prediction framework has been developed that simulates the entire processes of intergranular cavity nucleation and growth, together their coalescence into grain boundary cracks. The roles of precipitate kinetics on or near grain boundaries, and stress relaxation due to precipitate-dependent viscoplastic deformation can also be incorporated and investigated. |
Proceedings Inclusion? |
Definite: Other |