The corrosive effects of a molten nitrate mixture of 48% Ca(NO3)(2)+7% NaNO3+45% KNO3 were appraised at 390 degrees C on two different types of stainless steels (AISI 304, 430), a low-Cr alloy steel (T22) and a carbon steel (A1). The corrosion rates were determined using gravimetric tests, which measured the weight gain during 2000 h to identify the corrosion products with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Studies on stainless steel revealed a better behaviour in corrosive environment, which mainly identifies the formation of (K,Na)CrO4 protective spinel. Fe2O3 and Fe3O4 were the other important products that were found in the tests performed at 390 degrees C; the formation of some stable compounds with salt impurities, such as carbonates and sulphates, was also observed. (C) 2015 Elsevier B.V. All rights reserved.