کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1471661 990356 2008 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Quantum chemical molecular dynamics study of stress corrosion cracking behavior for fcc Fe and Fe–Cr surfaces
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Quantum chemical molecular dynamics study of stress corrosion cracking behavior for fcc Fe and Fe–Cr surfaces
چکیده انگلیسی

Quantum chemical molecular dynamics simulation was applied to study the oxidation of bare Fe (1 1 1) and Fe–Cr (1 1 1) surfaces with strain in high temperature water. Simulation results implied the surface morphologies differ from Fe to Fe–Cr because of strong bond between oxygen and chromium atoms. Oxygen atoms were trapped around chromium atoms at Fe–Cr surface, whereas oxygen penetrated into the lattice of Fe bare surface. As a result, the oxygen diffusivity into the Fe–Cr crystal surface reduced. It indicated that the preferential oxidation of chromium would take place on Fe–Cr clean surface at the beginning of the oxidation process. Diffusion of hydrogen and oxygen significantly increased when strain applied to the defective surface. Hydrogen atoms being in the lattice of metal possessed the highly negative charge which indicated the surface oxidized by this negative charge H. Negative charged oxygen atoms make bond with the metallic atom which breakage ultimate metal–metal bond. These bond breakages indicated the formation of oxide layer on the surface and play a key role in subsequent localized corrosion nucleation like stress corrosion cracking.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Corrosion Science - Volume 50, Issue 6, June 2008, Pages 1701–1706
نویسندگان
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