Surface Characterization of 309 and 310 Steel after the Corrosion in Wood Biomass Ash

The aim of this study was to investigate the influence of biomass ashes - specifically wood biomass ash - on the surface of austenitic stainless steel 309 and 310. The process was carried out for 1000 h at 650°C. The microstructure and chemical composition of corrosion products were examined by scanning electron microscopy with energy dispersive spectroscopy analysis. Phase analysis of corrosion product were done by X-ray diffraction and ash composition was investigated by X-ray fluorescence. It was observed that wood biomass ash caused the corrosion of the steel surface. On the surface of the steels exposed to wood biomass ash the layer of corrosion products was observed, mostly chromium, nickel and iron oxide. The thickness of mill scale formed during the process was in the range of h=15-30 μm.