Performance Analysis of Fe-Cr Alloys Inside a Corrosive Environment at High Temperatures 500 and 600 °C

The new requirements for materials with improved properties and resistance to hazardous aggressive environments is very important in industrial incinerators and stoves. Thus, the present manuscript is dedicated to the study of the chemical interaction between Fe-Cr alloys at high temperatures (500–600 °C). Four alloys with different Al, Si, and Mo chemical composition were tested to determine their resistance to active laboratory conditions. The conditions were established based in those inside waste disposal incinerators. Laboratory equipment was set up to reproduce an enclosed aggressive but controlled atmosphere. Cylinders filled with N2 and O2 generated an 8% vol, and other containers produced a 220 vppm of HCl, 360 Vppm of H2O, and 200 vppm of SO2. The exposition was not continuous because the goal was to analyze the material response along different exposition times. The corrosion products that resulted after chemical etching were characterized using Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), and taking an average of various thermo-gravimetric measurements. The main products were Cr2O3, Fe2O3, Fe0.6Cr0.4, and Fe and Cr. The alloy with the best performance was found and theoretical principles of corrosion were analyzed to understand the corrosion mechanisms, which were driven by the formation of non-protective oxides.