Increase of the energy recovery efficiency facilities is one of the challenges fixed recently by UE to Municipal Solid Waste Incineration (MSWI) operators. To achieve this target, one option consists in optimizing the water/steam cycle to increase electrical efficiency. Nevertheless, higher steam temperature into heat exchanger tube is expected to increase the risks of fireside corrosion, particularly on superheater tubes, along with important loss of materials, frequent shutdowns for repairs and high operational costs. In this study, fireside corrosion test had been performed using an innovative laboratory-scale corrosion pilot. Effect of increase in metal temperature from 400°C to 450°C on corrosion performances of SA192 carbon steel tube and AISI 316L stainless steel had been examined. Mechanisms and corrosion rates are discussed with regards to lifetime reported for both materials after 1 year in service in the same plant.