Neutron study and modeling of the lattice parameters in a NiAl-precipitate strengthened ferritic steel

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Acta Materialia

DOI:https://doi.org/10.1016/j.actamat.2012.05.033· OSTI ID:1048731

Teng, Zhenke ^[1]; Ghosh, Gautam ^[2]; Miller, Michael K ^[1]; Huang, Shenyan ^[1]; Clausen, B ^[3]; Brown, D. W. ^[3]; Liaw, Peter K ^[4]

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1. ORNL
2. Northwestern University, Evanston
3. Los Alamos National Laboratory (LANL)
4. University of Tennessee, Knoxville (UTK)

The lattice misfit between the body-centered cubic {alpha}-Fe matrix and the B2-ordered NiAl-type {beta}{prime} precipitates is a parameter of significant importance in controlling the creep resistance of precipitate-strengthened ferritic steels. However, the measurement of the lattice misfit is complicated due to the fact that the fundamental reflections of {alpha} and {beta}{prime} phases almost completely overlap. In this study, neutron diffraction is used to determine the lattice parameters of these two phases in a Fe-18.9 Al-9.8 Cr-13 Ni-1.8 Mo (atomic percent, at.%) alloy as a function of temperature. The accuracy of the measurement at room temperature is verified by high-energy synchrotron X-ray diffraction. The comparison between these two techniques is discussed in terms of the difference in superlattice intensity. Furthermore, using the phase compositions determined by atom probe tomography, models are proposed to predict the lattice parameters of both phases at room temperature as a function of their compositions. The results are in very good agreement with those obtained experimentally.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Shared Research Equipment Collaborative Research Center
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1048731
• Journal Information: Acta Materialia, Vol. 60, Issue 13-14; ISSN 1359-6454
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACCURACY
ALLOYS
ATOMS
CREEP
FERRITIC STEELS
LATTICE PARAMETERS
NEUTRON DIFFRACTION
PRECIPITATION
PROBES
SIMULATION
SUPERLATTICES
SYNCHROTRONS
TOMOGRAPHY
X-RAY DIFFRACTION