KCl aqueous solutions were annealed for a long time at a temperature of several tens of degree higher than the equilibrium temperature and the resulting effect on the metastable zone width (MSZW) and incubation period for nucleation was studied. The investigated solutions were pure, acidic (pH = 2.6), and Pb ion-doped solutions. It was found that both MSZW and incubation period were enlarged by the overheating treatment and its effect on the crystal growth was also examined. (c) 2006 Elsevier B.V. All rights reserved.