Modeling bulk diffusion of hydrogen in X70 pipeline steel

Hydrogen bulk diffusion and saturation of X70 pipeline steel was investigated by employing high-pressure gaseous hydrogen charging, thermal desorption analysis/spectroscopy (TDA/TDS) and numerical modeling/simulation of bulk diffusion. The trapping model was inversely parametrized using electrochemical hydrogen charging. The predictions made based on the model were validated with an independent set of experimental data that had been generated using high-pressure gaseous hydrogen charging, and literature data was used to verify the results of the simulations. It turned out that the bulk diffusion model is a unified approach that enables simulating hydrogen diffusion, trapping and saturation of X70 pipeline steel. Independently from the source of hydrogen the model can be used with high accuracy.