Probing the effects of hydrogen on the materials used for large-scale transport of hydrogen through multi-scale simulations

The successful realization of a hydrogen economy is crucially dependent on a comprehensive understanding of the effects of hydrogen on the hydrogen infrastructure materials and the development of hydrogen compatible materials with long term reliability. Progress made in recent times in understanding the fundamentals of hydrogen embrittlement mechanisms in metallic materials has been reviewed. Particular emphasis has been made on highlighting the challenges and breakthroughs made in the simulation of hydrogen effects across multiple length-scales using the density functional theory (DFT) method, molecular dynamics (MD) simulations and continuum approaches. The DFT approach is an important approach that provides valuable insights on the effects of hydrogen on a material due to intrinsic factors such as microstructural features and extrinsic factors such as temperature and pressure. MD simulations of hydrogen effects with new interaction potential functions that include more elements (such as Si, Mn, Cr, Ni, etc.) in models with internal defects (such as vacancies) and subjected to strain and temperature, could transform MD simulations from a mechanism studying tool to a property prediction tool. The continuum levels models have the potential to incorporate the effects of microstructural features and predict the mechanical performance of materials, such as deformation and fatigue life under hydrogen environments. Overall, there is positive outlook for developing multi-scale computational tools for designing hydrogen compatible materials and for predicting the performance of metallic materials in hydrogen environments using a bottom-up approach.