Abstract
Hydrogen is known to degrade the mechanical performance of many metals and alloys, often leading to brittle fracture. However, the presence of measurable plastic deformation prior to failure in hydrogen-exposed systems indicates that dislocation activity plays a significant role in the fracture process. Building on this, recent models of hydrogen-assisted cracking propose a synergistic interaction between hydrogen-induced modifications to both plasticity and cohesive strength. Traditional assessments of hydrogen effects on plasticity—typically employing techniques such as nanoindentation and transmission electron microscopy—are limited by their localised nature and sensitivity to microstructural heterogeneity. This study adopts a complementary, texture-based approach to assess hydrogen’s influence on deformation behaviour over larger representative volumes. Uniaxial tensile experiments on hydrogen-charged and non-charged polycrystalline nickel deformed to a true plastic strain of ~0.1 at room temperature and 77 K reveal that hydrogen has no measurable effect on texture evolution. Texture measurements were completed on samples of each condition, as well as an as-received reference, using electron backscatter diffraction (EBSD) data from over 20,000 individual grains. Crystal plasticity simulations support the conclusion that this similarity arises from the insensitivity of small-strain deformation textures to expected hydrogen-induced modifications in slip behaviour. To address this limitation and more clearly reveal the influence of hydrogen on texture evolution at higher strains, a novel methodology combining cold-rolling deformation and X-ray diffraction (XRD) texture analysis is currently under development.