Heat exchangers pipes for thermal power plants to coal suffer wear corrosive due to the presence of sulfur and condensation of combustion gases, which results in a reduction in overall equipment efficiency. A choice for increasing the corrosion resistance in corrosive environments is the use of coatings applied by thermal spray technology. The corrosion resistance occurs to the use of materials stronger than the substrate. the processes are thermal spray, which uses the electric arc as a source of energy (Arc Spray) has a high deposition rate and low operating costs, so chosen for the study. For the determination of the coating to be used, corrosion-resistant alloys were tested in comparison with material employed in the pipes of heat exchangers, ASTM 178A. The selection of the most resistant coating was made by means of accelerated corrosion test in SO2 chamber and also by testing polarization. It was found that the aluminum coating had the best results in the tests when compared with materials currently used in the heat exchangers (ASTM 178A).
Coal; Corrosive wear; Coating; Aluminum
