This paper presents a physically-based microstructural model for creep rupture at 600 degrees °C for Grade 91 steel. The model includes constitutive equations that reflect various observed phenomena in Grade 91, and it is incorporated into a mesoscale finite element model with explicit geometry for the prior austenite grains and grain boundaries. Creep within the grains is represented using crystal plasticity for dislocation motion and recovery along with linear viscous diffusional creep for point defect diffusion. The grain boundary models include physics-based models for cavity growth and nucleation that accurately capture tertiary creep and creep rupture. Simulations of creep at 100 MPa are performed, and the contribution of each mechanism is analyzed. The overarching goal is to gain a mechanistic understanding of the material to improve the prediction of creep rupture for long service lives in elevated temperature operating conditions. The creep response of the material at different stress levels, stress states, and temperatures is studied in Part 2 of this paper in order to determine the implications of the simulations on high temperature design practice. Furthermore, the second part explores the effect of triaxial stress states on the creep response and finds a transition from notch-strengthening behavior at high stress to notch-weakening behavior at lower stresses.
Nassif, Omar, et al. "Combined crystal plasticity and grain boundary modeling of creep in ferritic-martensitic steels: I. Theory and implementation." Modelling and Simulation in Materials Science and Engineering, vol. 27, no. 7, Aug. 2019. https://doi.org/10.1088/1361-651X/ab359c
Nassif, Omar, Truster, Timothy J., Ma, Ran, Cochran, Kristine B., Parks, David M., Messner, M. C., & Sham, T-L (2019). Combined crystal plasticity and grain boundary modeling of creep in ferritic-martensitic steels: I. Theory and implementation. Modelling and Simulation in Materials Science and Engineering, 27(7). https://doi.org/10.1088/1361-651X/ab359c
Nassif, Omar, Truster, Timothy J., Ma, Ran, et al., "Combined crystal plasticity and grain boundary modeling of creep in ferritic-martensitic steels: I. Theory and implementation," Modelling and Simulation in Materials Science and Engineering 27, no. 7 (2019), https://doi.org/10.1088/1361-651X/ab359c
@article{osti_1574947,
author = {Nassif, Omar and Truster, Timothy J. and Ma, Ran and Cochran, Kristine B. and Parks, David M. and Messner, M. C. and Sham, T-L},
title = {Combined crystal plasticity and grain boundary modeling of creep in ferritic-martensitic steels: I. Theory and implementation},
annote = {This paper presents a physically-based microstructural model for creep rupture at 600 degrees °C for Grade 91 steel. The model includes constitutive equations that reflect various observed phenomena in Grade 91, and it is incorporated into a mesoscale finite element model with explicit geometry for the prior austenite grains and grain boundaries. Creep within the grains is represented using crystal plasticity for dislocation motion and recovery along with linear viscous diffusional creep for point defect diffusion. The grain boundary models include physics-based models for cavity growth and nucleation that accurately capture tertiary creep and creep rupture. Simulations of creep at 100 MPa are performed, and the contribution of each mechanism is analyzed. The overarching goal is to gain a mechanistic understanding of the material to improve the prediction of creep rupture for long service lives in elevated temperature operating conditions. The creep response of the material at different stress levels, stress states, and temperatures is studied in Part 2 of this paper in order to determine the implications of the simulations on high temperature design practice. Furthermore, the second part explores the effect of triaxial stress states on the creep response and finds a transition from notch-strengthening behavior at high stress to notch-weakening behavior at lower stresses.},
doi = {10.1088/1361-651X/ab359c},
url = {https://www.osti.gov/biblio/1574947},
journal = {Modelling and Simulation in Materials Science and Engineering},
issn = {ISSN 0965-0393},
number = {7},
volume = {27},
place = {United States},
publisher = {IOP Publishing},
year = {2019},
month = {08}}
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE), Nuclear Reactor Technologies (NE-7); USDOE Office of Science (SC)
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1574947
Alternate ID(s):
OSTI ID: 22924437
Journal Information:
Modelling and Simulation in Materials Science and Engineering, Journal Name: Modelling and Simulation in Materials Science and Engineering Journal Issue: 7 Vol. 27; ISSN 0965-0393
ASME 2010 Pressure Vessels and Piping Division/K-PVP Conference, ASME 2010 Pressure Vessels and Piping Conference: Volume 6, Parts A and Bhttps://doi.org/10.1115/pvp2010-25297