Molecular dynamics simulation of porous layer-induced stress in Fe single crystal

• Published in: Computational materials science 2010-09, Vol.49 (3), p.641-644
• Main Authors: Li, D., Meng, F.Y., Ma, X.Q., Qiao, L.J., Chu, W.Y.
• Format: Article
• Language: English
• Subjects: Analysing. Testing. Standards; Applied sciences; Deflection; Exact sciences and technology; Fe single crystal; Iron; Lattice vacancies; Metals. Metallurgy; Molecular dynamics; Molecular dynamics simulation; Porous layer-induced stress; Single crystals; Stress analysis; Stress concentration; Stress corrosion cracking; Stresses; Tensile stress
• ISSN: 0927-0256; 1879-0801
• DOI: 10.1016/j.commatsci.2010.06.006

Pipeline steel in soil containing water could induce a macro tensile stress, leading to stress corrosion cracking (SCC). Porous layer-induced stress in Fe single crystal with various vacancy distributions on the surface layer is studied using molecular dynamics. The results show that Fe single crystal with one end fixed and a porous layer on the surface is deflected toward the porous layer during relaxation, resulting in a macro tensile stress. There is a maximum tensile stress in the matrix near the interface between the porous layer and the matrix resulting from the porous layer. The average stress on the porous layer σ xx ( d), which is calculated based on the measured deflection, increases with the increase of the maximum vacancy concentration C V on the top surface and the relative depth of the porous layer d/ B. And the macro tensile stress σ xx ( B) on the cross section of the sample increases also with the increase of C V and d/ B. σ xx ( B) is approximately four times smaller than σ xx ( d).