Abstract: Mechanism for diffusion of B in γ-Fe is believed to be mainly by means of boron-vacancy complexes other than as interstitial atoms previously.This was made of calculation on the ba- sis of theoretical model proposed by the authors.The calculated diffusion coefficient of B in γ-Fe after this mechanism is consistent with the experimental values.In addition,this is also supported by the non-equilibrium segregation phenomenon of B at grain boundaries of γ-Fe and the lattice constant measurement of Fe-B alloy.

Key words: boron, vacancy, diffusion, non-equilibrium segregation, γ-Fe