Corrosion Resistance of 309s Steel CMT-Cladded Layers after Long-Term Exposure to Biomass

Abstract

The aim of the research presented was to investigate the influence of different biomass ash at corrosion condition T = 650°C for 2000 h on the surface of weld cladded (CMT) stainless steels 309. The biomass ashes are rich in K₂O, CaO, SiO₂, whereas sewage sludge ash in P₂O₅, CaO, Fe₂O₃ and SiO₂. Characterization of the stainless steel cross-section after the corrosion process inducted by the presence of ash were carried out SEM with EDS analysis. Phase analysis of corrosion products was made by X-ray diffraction (XRD) and simulated using FactSage version 8.3. It has been proved that biomass ashes have the corrosive properties, due to the presence of potassium, and are more aggressive than the sewage sludge ash.