[en] Radial friction coefficient in relative motion of nuclei at deep inelastic collisions was calculated in the framework of microscopic approach. Friction coefficients, obtained in different models, are correlated. Self-consistent calculations of collision trajectories and internal nucleus excitations were conducted. It was established that total release of kinetic energy did not always take place in reactions of deep inelastic transfers, and the duration of release of the main part of kinetic energy could achieve 5 x 10^-22 s, depending on angular moment of collision. 16 refs, 3 figs