Corrosion behavior of hot-dip aluminized coating formed on type 310S stainless steel was studied for the first time in carbonate melt at 650 degrees C for solar-thermal applications. The heat pre-treatment at 800 degrees C for 24 h endowed the coating with a high interdiffusion resistance at 650 degrees C. Polishing out the rough outer surface of the coating enabled better estimation of the corrosion resistance. The aluminized coating having dense layers quickly and sufficiently alloyed with Cr by the high temperature heat pretreatment showed enhanced corrosion resistance in carbonate melt. Mass loss and electrochemical tests confirmed that the heat pre-treated aluminized coating decreased the corrosion rate of 310S stainless steel at least by two orders of magnitude. The formation of a similar to 50 nm thick passive film of lithiated-alumina on the coating is responsible for the high corrosion resistance. (C) 2018 The Electrochemical Society.