In this work, preliminary results of the corrosion rate in a saline solution (3 wt% NaCl) of gray iron samples in as-cast and heat treatment conditions were studied. Optical microscopy was carried out to characterize the microstructures of the gray iron in all conditions. The corrosion tests were achieved by using the Tafel electrochemical technique. The lowest corrosion rate was obtained for the normalized condition while the higher values were obtained for the austempering condition at 320 °C.