Using ab initio density functional theory calculations, an investigation was made of the influence of Mo, V and Pd on the H-induced grain boundary embrittlement in Fe. It was found that, in the high impurity concentration systems, all of the three alloying elements facilitate H embrittlement at the Σ3 (111)[1¯10] grain boundary in Fe. The calculated binary effects of the H–X (X = Mo, V, Pd) couples were 0.063, 0.074 and 0.040eV, respectively. On the other hand, in the large unit cell with low impurity concentration, both Mo and V could facilitate H embrittlement, and the binary effects of pairs were 0.152 and 0.164eV, respectively. While Pd reduces the H embrittlement on the cohesion of the Fe grain boundary with the binary effect of −0.1eV. The H–X (X = Mo, V, Pd) interactions were interpreted by electronic structure analyses.

Effect of Alloying Additions on the Hydrogen-Induced Grain Boundary Embrittlement in Iron. Z.X.Tian, J.X.Yan, W.Hao, W.Xiao: Journal of Physics - Condensed Matter, 2011, 23[1], 015501