Molecular Dynamics Simulation of Microstructure Evolution and Deformation Mechanism for X80 Steel

Abstract

X80 steel which was used in buried gaspipeline mainly consists of ferrite and pearlite. Experiments show that two kinds of micro defects exist inevitably in the manufacturing process of X80 steel including the micro-void and micro-crack, which affect the mechanical properties of X80 steel significantly. In this study, the deformation and failure processes of the composition of X80 steel near defects at atomic scale level were examined by means of molecular dynamics (MD) simulation. The EAM/FS potential is employed to characterize the interatomic interactions of the composition of X80 specimens. The deformation and failure processes of single crystal structures forï¡-Fe, Fe3C and the Fe3C-Fe interface are observed around the crack. The results reveal that microstructure evolution and deformation mechanism under external loading are correlated with crystal structure and crystal orientation intrinsically.