Hydrogen trapping in some advanced high strength steels

• Permeability experiments were used to study hydrogen diffusion and trapping.
• The trapping effect was less significant at a more negative charging potential.
• The lattice diffusion coefficient of hydrogen was measured.
• The densities of reversible hydrogen trap sites was ∼ 2 × 1018 sites cm−2.

Permeability experiments were used to study hydrogen diffusion and trapping in dual phase (DP), quenched and partitioned (Q&P), advanced high strength steels. The measured reversible hydrogen trap densities indicated that (i) trapping was less significant at a more negative potential, and (ii) the lattice diffusion coefficient of hydrogen could be measured from the partial transients at the most negative potentials. The densities of reversible hydrogen traps evaluated from complete decays from −1.700 VHg/HgO were ∼ 2 × 1018 sites cm−3, and were a factor of two higher than those from partial decay transients between −1.700 VHg/HgO and −1.100 VHg/HgO.