The shift of internal friction grain boundary maximum temperature (Ke-peak) versus the generation rate of point defects has been investigated in pure nickel and iron as well as in austenitic steel and a Fe^-11B alloy. The obtained data allows the estimation of the excess fluxes of both the radiation-caused vacancies to grain boundaries and interstitials to dislocations. These fluxes are linearly dependent on the generation rate of defects in pure nickel and iron, while for both the stainless steel and iron-boron alloy for the temperature interval of 700 to 950 K in the generation rate region of 10^-4 - 2.4 × 10^-8 dpa ∙ s^-1, the dependence is nonlinear. This is probably connected with the fact that mutual vacancy-interstitial recombination does not affect the accumulation and annealing of defects in nickel and iron, but recombination may be essential in stainless steel and iron-boron alloys. To estimate the tendency toward radiation swelling, the value of point defects' (vacancies or interstitials) excess flux to the generation rate of defects ratio has been introduced.