The microstructure of the alloy and chemical composition of phases in as-cast and heat-treated conditions were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy. It has been shown that at high heating and cooling rates the thickness of the alpha(2) and gamma lamellae decreases. Also, under these conditions the surface area of the grain boundaries decreases. Higher annealing temperatures in the two-phase (gamma + alpha) range and low cooling rates led to a lamellar microstructure. Annealing near the eutectoid temperature resulted in degeneration of the initial lamellar microstructure. (C) 2003 Elsevier Science B.V. All rights reserved.