Effect of transient trapping on hydrogen transport near a blunting crack tip

The paper revisits the way transient trapping is introduced in the literature based on the Sofronis and McMeeking model (Sofronis and McMeeking, 1989) [1] of hydrogen transport. It is shown that the direct use of the improved formulation made by Krom et al. (1999) [2] for transient trapping may lead to non-physical results of hydrogen concentration in case of an insulated system. The use of McNabb and Foster trapping kinetic equation is more relevant, and its ability to model both trap creation and kinetic trapping is investigated on a Small Scale Yielding configuration for the sake of comparison with a reference case from the literature. A parametric study is conducted, exhibiting differences with literature, and emphasizes on the significant effect of trapping kinetics on the hydrogen distribution. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

The paper revisits the transient trapping model for hydrogen transport and finds that the improved formulation may lead to non-physical results in insulated systems. The McNabb and Foster trapping kinetic equation is more relevant and has a significant effect on the hydrogen distribution.