Modeling of chromium precipitation in Fe-Cr alloys

Wallenius, Janne; Olsson, Per; Lagerstedt, Christina; Sandberg, Nils; Chakarova, R.; Pontikis, V.

doi:10.1103/physrevb.69.094103

Cited by 89 publications

(72 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The pair interaction and the many-body functionals for Fe in the 2BM potential were developed by Ackland et al [17] and the potential for Cr by Olsson et al [15,18,19]. The density function in the Cr potential has the same shape as the one used for Fe.…”

Section: Methodsmentioning

confidence: 99%

Simulation of displacement cascades in Fe90Cr10 using a two band model potential

Björkas

Nordlund

Malerba

et al. 2008

Journal of Nuclear Materials

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Simulation of displacement cascades in Fe90Cr10 using a two band model potential

Björkas

Nordlund

Malerba

et al. 2008

Journal of Nuclear Materials

Self Cite

View full text Add to dashboard Cite

“…In rigid lattice MC simulations [12,20,[34][35][36][37] using Ising-type interaction the Hamiltonian must be made temperature dependent. Semiempirical potentials have been used in both Metropolis MC (MMC) [38][39][40] and kinetic MC (KMC) [9,[41][42][43][44][45][46][47] studies. All works on kinetics are bulk simulations of single-crystal alloys and diffusion mediated by a single vacancy.…”

Section: B Large-scale Monte Carlo Simulationsmentioning

confidence: 99%

Segregation, precipitation, andα−α′phase separation in Fe-Cr alloys

et al. 2015

View full text Add to dashboard Cite

Iron-chromium alloys, the base components of various stainless steel grades, have numerous technologically and scientifically interesting properties. However, these features are not yet sufficiently understood to allow their full exploitation in technological applications. In this work, we investigate segregation, precipitation, and phase separation in Fe-Cr systems analyzing the physical mechanisms behind the observed phenomena. To get a comprehensive picture of Fe-Cr alloys as a function of composition, temperature, and time the present investigation combines Monte Carlo simulations using semiempirical interatomic potential, first-principles total energy calculations, and experimental spectroscopy. In order to obtain a general picture of the relation of the atomic interactions and properties of Fe-Cr alloys in bulk, surface, and interface regions several complementary methods have to be used. Using the exact muffin-tin orbitals method with the coherent potential approximation (CPA-EMTO) the effective chemical potential as a function of Cr content (0-15 at. % Cr) is calculated for a surface, second atomic layer, and bulk. At ∼10 at. % Cr in the alloy the reversal of the driving force of a Cr atom to occupy either bulk or surface sites is obtained. The Cr-containing surfaces are expected when the Cr content exceeds ∼10 at. %. The second atomic layer forms about a 0.3 eV barrier for the migration of Cr atoms between the bulk and surface atomic layer. To get information on Fe-Cr in larger scales we use semiempirical methods. However, for Cr concentration regions less than 10 at. %, the ab initio (CPA-EMTO) result of the important role of the second atomic layer to the surface is not reproducible from the large-scale Monte Carlo molecular dynamics (MCMD) simulation. On the other hand, for the nominal concentration of Cr larger than 10 at. % the MCMD simulations show the precipitation of Cr into isolated pockets in bulk Fe-Cr and the existence of the upper limit of the solubility of Cr into Fe layers in Fe/Cr layer systems. For high Cr concentration alloys the performed spectroscopic measurements support the MCMD simulations. Hard x-ray photoelectron spectroscopy and Auger electron spectroscopy investigations were carried out to explore Cr segregation and precipitation in the Fe/Cr double layer and Fe 0.95 Cr 0.05 and Fe 0.85 Cr 0.15 alloys. Initial oxidation of Fe-Cr was investigated experimentally at 10 −8 Torr pressure of the spectrometers showing intense Cr 2 O 3 signal. Cr segregation and the formation of Cr-rich precipitates were traced by analyzing the experimental atomic concentrations and chemical shifts with respect to annealing time, Cr content, and kinetic energy of the exited electron.

show abstract

“…The latter constitute for us what we take as experimental values although not all data in the database are from experimental assessment. In this work, we use the Fe potential reported by Mendelev et al [12] and the Cr potential reported by Wallenius et al [13]. The formation energy for FeCr has recently been calculated by Olsson et al [14] together with a rough estimate of the bulk modulus and lattice parameter of the alloy as a function of composition.…”

mentioning

confidence: 99%