|About this Abstract
||2010 TMS Annual Meeting & Exhibition
||Computational Thermodynamics and Kinetics
||Quantifying the Strength of Point Defect Based Hydrogen Traps in Bcc and Fcc Iron
||William A Counts, Chris Wolverton, Ron Gibala
|On-Site Speaker (Planned)
||William A Counts
Hydrogen embrittlement of iron and steels is a classic but still unresolved problem in metallurgy. While hydrogen can freely move through the Fe lattice, its diffusion is hindered by lattice imperfections. Experimentally quantifying the binding energy of hydrogen to these defects has proven to be difficult. Fortunately, computational tools are ideally suited to study defect trapping because it is possible to isolate individual traps.
Density function theory was used to quantify the binding energy of hydrogen to a number of point defects in both bcc and fcc Fe. In bcc Fe, vacancies are the strongest hydrogen trap with a binding energy of 0.57 eV. The binding energies of common alloying elements are significantly less and range between -0.08 - 0.20 eV. Using a number of different anti-ferromagnetic configurations to model the paramagnetic state in fcc Fe, we found the hydrogen-vacancy binding energy to be between 0.20-0.36 eV.
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