Micromechanical finite element modelling of thermo-mechanical fatigue for P91 steels

Li, Dong-Feng; Barrett, Richard A.; O�Donoghue, Padraic E.; Hyde, Christopher J.; O�Dowd, Noel P.; Leen, Sean B.

Abstract

In this paper, the cyclic plasticity and fatigue crack initiation behaviour of a tempered martensite ferritic steel under thermo-mechanical fatigue conditions is examined by means of micromechanical finite element modelling. The crystal plasticity-based model explicitly reflects the microstructure of the material, measured by electronic backscatter diffraction. The predicted cyclic thermo-mechanical response agrees well with experiments under both in-phase and out-of-phase conditions. A thermo-mechanical fatigue indicator parameter, with stress triaxiality and temperature taken into account, is developed to predict fatigue crack initiation. In the fatigue crack initiation simulation, the out-of-phase thermo-mechanical response is identified to be more dangerous than in-phase response, which is consistent with experimental failure data. It is shown that the behaviour of thermo-mechanical fatigue can be effectively predicted at the microstructural level and this can lead to a more accurate assessment procedure for power plant components.

Citation

Li, D., Barrett, R. A., O’Donoghue, P. E., Hyde, C. J., O’Dowd, N. P., & Leen, S. B. (2016). Micromechanical finite element modelling of thermo-mechanical fatigue for P91 steels. International Journal of Fatigue, 87, https://doi.org/10.1016/j.ijfatigue.2015.11.025

• Journal Article Type: Article
• Acceptance Date: Nov 25, 2015
• Online Publication Date: Jan 21, 2016
• Publication Date: Jun 4, 2016
• Deposit Date: Jul 29, 2016
• Publicly Available Date: Jul 29, 2016
• Journal: International Journal of Fatigue
• Print ISSN: 0142-1123
• Electronic ISSN: 0142-1123
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 87
• DOI: https://doi.org/10.1016/j.ijfatigue.2015.11.025
• Keywords: Tempered martensite ferritic steels; Thermo-mechanical fatigue; Crystal plasticity; Fatigue crack initiation; Finite element
• Public URL: https://nottingham-repository.worktribe.com/output/796655
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0142112315004247