Silicon/silicon oxide coating on AISI 304 stainless steel by CVD in FBR: analysis of silicides and adherence of coating

Silicon can be deposited and diffused on AISI 304 surfaces to increase corrosion resistance in aqueous acidic environments, high temperature oxidation and erosion resistance. This coating has been obtained by chemical vapor deposition in a fluidized bed reactor (CVD-FBR) at relatively low temperatures (450–550 °C). The deposition of silicon on AISI 304 steel can lead to the formation of interfacial silicide compounds (Fe3Si, Fe5Si3, FeSi and FeSi2). However, the adherence of these coatings is not good when the amount of Si is increased. We studied the best conditions to deposit Si on AISI 304 to minimize the formed corrugated and non-adherent silicide layer. We have optimized the silicon coatings on the stainless steels at temperatures of 450 °C for 60 min. Optical microscopy, XRD and scanning electron microscopy/energy dispersive X-ray spectroscopy have been employed to characterize the obtained products. The results will show that some CVD-FBR silicon coating types are expected to provide.