The Fe–C–H interaction in a dislocated body-centered cubic structure was studied by using qualitative structure calculations within the framework of the atom superposition and electron delocalization molecular orbital theory. The calculations were performed by using Fe85 clusters to simulate a dislocated body-centered cubic structure. The cluster geometry and atomic parameters were optimized to make a better approximation to the repulsive energy terms. The most stable position for a C atom within the cluster was determined. Therefore, and H atom was approximated by the minimum energy region where the C atom had previously been located. The total energy of the cluster decreased with the C atom near the dislocation core. The a/2[1¯11] dislocation created an energetically favourable zone for the accumulation of C. The presence of C in the dislocation core caused no favourable H accumulation. The C acted so as to expel H, and could reduce the weakening of Fe–Fe bonds. In addition, a sort of Fe–C–Fe bridge could prevent dislocation displacement if a shear stress was applied.

The Electronic Effect of Carbon and Hydrogen in an (1¯11) Edge Dislocation Core System in BCC Iron. S.Simonetti, M.E.Pronsato, G.Brizuela, A.Juan: Applied Surface Science, 2003, 217[1-4], 56-67