A critical review of mathematical models used to determine the density of hydrogen trapping sites in steels and alloys

Hydrogen trapping in some advanced high strength steels

“…Hydrogen atoms are located in interstitial sites and are trapped by microstructure features such as voids, dislocations, grain boundaries, carbide interfaces, and impurities [16][17][18]. These hydrogen traps play an important role in the transportation and distribution of hydrogen in the steel [18].…”

Reversible hydrogen trapping in a 3.5NiCrMoV medium strength steel

“…Araújo et al [29] critically reviewed the mathematical models for determining the density of hydrogen trapping sites in steels, N T , including: (i) the model proposed by Oriani [19] and refined by Yen and Huang [51], and (ii) the model proposed by Oriani [19] and refined somewhat differently by Dong et al [52]. The latter model is herein designated the Oriani-Dong model reflecting the combined contribution to the model.…”

Effect of Cementite on the Hydrogen Diffusion/Trap Characteristics of 2.25Cr-1Mo-0.25V Steel with and without Annealing

“…The grain boundaries are often denoted as hydrogen traps. The hydrogen trap density $N_T$ (m −3 ) can be estimated as follows [20,21,22]:$N_T=\frac{C_0}{3}\left(\frac{D_l}{D_{eff}}-1\right)\times N_A$ where $D_l$ is the lattice diffusion coefficient of hydrogen (m 2 ·s −1 , $1.28\times {10}^{-4}$ m 2 ·s −1 in ferrite [22,23] and $N_A$ is Avogadro’s number ($6.022\times {10}^{23}$ mol −1 ). The hydrogen trap density values calculated with this expression are listed in Table 3.…”