Recent Advances in the Study of Structural Materials Compatibility with Hydrogen

Abstract

Hydrogen is a ubiquitous element that enters materials from many different sources. It almost always has a deleterious effect on mechanical properties. In non-hydride-forming systems, research to date has identified hydrogen-enhanced localized plasticity and hydrogen-induced decohesion as two viable mechanisms for embrittlement. However, a fracture prediction methodology that associates macroscopic parameters with the degradation mechanisms at the microscale has not been established, as of yet. In this article, we report recent work on modeling and simulation of hydrogen-induced crack initiation and growth. Our goal is to develop methodologies to relate characteristics of the degradation mechanisms from microscopic observations and first-principles calculations with macroscopic indices of embrittlement. The approach we use involves finite element analysis of the coupled hydrogen transport problem with hydrogen-assisted elastoplastic deformation, thermodynamic theories of decohesion, and ab initio density functional theory calculations of the hydrogen effect on grain boundaries.

Doping in the Valley of Hydrogen Solubility: A Route to Designing Hydrogen-Resistant Zirconium Alloys

“…The complexity of the microstructure [12] of the ZrO 2 passive layer during the corrosion process, radiation effects [56], and kinetic factors such as the dissolution rate of alloying elements in ZrO 2 and the diffusion of hydrogen in ZrO 2 warrant that future studies will add components to this framework. Hydrogen embrittlement or hydrogen-induced crack initiation is ubiquitous in many semiconducting [58,59] and metallic alloys including steels and Al-and Ni-based systems [60][61][62][63][64]. There is evidence that the severity of the embrittlement depends on the presence of a native oxide [15], through which hydrogen has to pass.…”

Hydrogen mapping in an aluminum alloy using an alternating current scanning electrochemical microscope (AC-SECM)

“…Hydrogen embrittlement is suspected to play a role in the mechanical degradation of various materials [1]. Hydrogen can be inserted into the lattice (interstitial hydrogen) or at microstructural defects (e.g.…”

First-principles investigation of hydrogen trapping and diffusion at grain boundaries in nickel

“…In the case of the HEDE mechanism, this critical concentration needs to be achieved in the vicinity of the failing GBs at an accumulation rate comparable with the propagation rate of a crack [12,13]. In order to fulfill this requirement, it is necessary for the H atoms to be both able to diffuse fast towards the GBs and become efficiently trapped there.…”