Influence of material inhomogeneity and variation of temperature on hydrogen diffusion as a risk factor of enhancement of metals hydrogen degradation

Through analysis of equations of hydrogen diffusion in metals in the presence of heterogeneous fields affecting hydrogen solubility in a solid it was shown that due to transient temperatures there can arise zones of temporarily non-equilibrium hydrogen supersaturation which may lead to hydrogen of material. The magnitude of local supersaturation of metal with hydrogen depends on the kinetics of temperature variation, material properties and spatial scales of heterogeneities. The role of microstructural and strain-induced solubility inhomogeneities was discussed as a cause of non-equilibrium supersaturation and prerequisite for hydrogen degradation of materials under thermocycling.