Effect of hydrogen on the electrical resistivity of Fe and Fe-C systems : a first principles study

Abstract

Hydrogen Embrittlement (HE) in steel is an important phenomenon that needs to be understood from several perspectives. HE promotes crack growth and lower ductility hence it poses a risk of failure in the material. An important aspect that needs further research in the domain of HE is the effect of hydrogen (H) on the physical properties of steel. A better understanding of this aspect could contribute to the development of a non-destructive testing technique for detecting the change in physical properties in the presence of H in the material. This study investigates the effect of Hconcentration on the electrical resistivity of iron (Fe) and ironcarbon (Fe-C) systems using density functional theory (DFT). An increase in resistivity with the increase in H-concentration was observed in both Fe and Fe-C systems. The addition of H and C to the Fe system is found to negligibly affect the density of states (DOS) at the fermi level which is proportional to the number of free electrons in the system. Whereas the addition majorly affects the probability of an incident electron wave being transmitted through the system in its transport direction by scattering it.