MEAM Seminar: “Powering the Future Through Hydrogen Hubs and International Partnerships for Materials and Engineering System Solutions”

The U.S. Department of Energy’s Energy Earthshots Initiative aims to accelerate breakthroughs of more abundant, affordable and reliable clean energy solutions, to tackle the toughest remaining barriers to addressing the climate crisis and achieving net-zero carbon emissions by 2050. Specifically, the Hydrogen Energy Shot seeks to reduce the cost of clean hydrogen by 80% in one decade. The regional clean hydrogen Hub initiative aims to catalyze the deployment of hydrogen into the economy through a network of producers, end-users, and required infrastructure.

In this presentation, after the introduction of the hydrogen hub initiative, the focus will be on the science and engineering of hydrogen/materials interactions. Development and validation of a lifetime prediction methodology for failure of materials used for hydrogen containment components requires thorough understanding of the deformation and fracture mechanisms at the atom- and micro-scale along with a mechanics approach to link these mechanisms with the macroscopically observed failure at the macroscale. We will try to establish this link between micro-scale and macro-scale through experiment, modeling, and simulation for a number of materials systems and failure modes.

Recent experimental studies of the microstructure beneath fracture surfaces of ferritic steel, lath martensitic steel, stainless steel, and nickel specimens fractured in hydrogen suggest that the dislocation structure and hydrogen transported by mobile dislocations play important roles in the evolution of the fracture process/event. After reviewing this plasticity-mediated hydrogen-induced failure, we present a number of models and simulations that can be used for the design against hydrogen-induced failure: i) for the case of low alloy martensitic steels results demonstrate that hydrogen induced failures are complex phenomena that can be explained by a combination of hydrogen-enhanced plasticity and decohesion and require factors such as stress, strain, and hydrogen concentration to all act in concert to bring about failure; ii) for ferritic systems subjected to cyclic loading, we present an approach to mitigate the hydrogen effect through a few molecules of oxygen per million molecules of hydrogen in order to markedly increase the magnitude of the stress intensity factor range at which hydrogen-accelerated fatigue commences; iii) at high temperatures and hydrogen pressures, internal hydrogen can accelerate creep deformation in steel and react with carbides to form internal methane gas with an associated loss in strength due to decarburization that can lead to fracture, a phenomenon known as high temperature hydrogen attack. Based on the underlying deformation and fracture mechanisms, we propose a new tool to ascertain fitness-for-service of components in service and the results are discussed in relation to the empirical Nelson curves that are used in industrial practice.