Our aim is to study qualitatively the process of QGP cooling and hadronization. Following the statistical theory of the first order phase transitions we have to operate with such categories as nucleation rate, pre-exponential factor, surface free energy of bubbles and velocity of bubble growth. We compute the temperature, average bubble size, bubble density and fraction of space converted to the hadronic phase as a function of time. Also, we check the sensitivity of our scenarios to variations of the parameters mentioned above, as well as different schemes of QGP expansion: from longitudinal to spherical expansion. The results obtained are compared to idealized adiabatic Maxwell equilibrium scenario.