The electronic structure and hydrogen gas-induced environmental embrittlement in Ni 4Mo alloy

Abstract

Atomic ordering is known to result in hydrogen gas-induced environmental embrittlement in Ni 4 Mo alloy. This paper addresses the question of why atomic ordering exacerbates the hydrogen gas-induced environmental embrittlement from the electronic structure using electron energy loss spectroscopy (EELS). EELS of the Ni L 3,2 edges showed that the atomic ordering increases the 3d occupancy per Ni atom and therefore increases the surface catalytic activity to dissociation molecular hydrogen into atomic hydrogen.