Understanding of Early Stage Oxidation Behavior on Ni Surface Using Ab-initio Molecular Dynamics

摘要

Nickel based alloys are one of the most important structural materials used in the modern nuclear industry because of their good corrosion resistance and mechanical properties that tolerate harsh and extreme environments. However, nickel-based alloys can be oxidized in high temperature aqueous environments. The oxidation of nickel-based alloys can be regarded as origin of the initiation of stress corrosion cracking (SCC), which is the main degradation process that induces failure in steam generator tubes and reactor vessel head penetration in nuclear power systems. However, many fundamental issues related to the oxidation mechanism have yet to be solved because SCC experiments require specialized environments and complex parameters. Therefore, a computational approach to understand the behavior of early stage oxidation has emerged with improvements in the computer performance. Thus, many researchers have begun to focus on atomistic modeling and simulations to evaluate the oxidation behavior of metals and alloys. Therefore, to investigate early stage oxidation, this study focuses on understanding the interaction between nickel substrates and oxygen molecules using the large-scale atomic/molecular massively parrallel simulator. molecular dynamics simulator with modified interatomic potentials for the nickel-oxygen system obtained from ab-initio methods.