High Temperature Corrosion Behavior of T91 in Alkali Metal Chloride Medium

The corrosion behavior of T91 was studied by simulating the gas-side condition in super-heater of a biomass power plant. The corrosion kinetics curves were obtained through mass gain. By SEM, EDS and XRD, the appearance, microstructure, element contents and composition of corrosion products on the samples after corrosion were analyzed. The results showed that the corrosion of T91 was very sensitive to the gaseous-phase of KCl and the reaction temperature, as the reaction temperature increased, the corrosion-resistant behavior of T91 reduced and the corrosion kinetics of T91 steel was in line with parabolic law. The main components of the corrosion product were Fe2O3 and (Fe0.6Cr0.4)2O3, a small amount of Fe3O4 and K2Fe4O7.