Improved resistance to hydrogen embrittlement in a high-strength steel by quenching-partitioning-tempering treatment

The effect of ε-carbide on hydrogen embrittlement (HE) susceptibility was evaluated in a quenching-partitioning-tempering (Q-P-T) treated steel. Total elongation loss (1 min hydrogen charging) drops from 42.7% to 0.6% after the tempering treatment. A significant improvement to HE is associated with the trapping capacity of ε-carbide, which is revealed by thermal desorption spectroscopy analysis and three-dimensional atom probe. A possible mechanism is discussed to explain the improved resistance to HE.