Degradation Studies of Wire arc Sprayed FeCrBSiMn Alloy Coating in Molten Salt Environment

The aim of the current investigation is fabricate the FeCrBSiMn alloy coating onto 310S stainless steel substrate by wire arc spraying process and to study degradation behavior of the coating exposed to molten salt environment (Na2SO4-82%Fe2(SO4)3) at 900 °C under cyclic conditions after 50 cycles. X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive analysis (SEM/EDS) were used to characterize morphology of coated and uncoated samples for substantiating the degradation mechanisms. The dense and globular morphology of the coatings is observed from the SEM analysis. The maximum microhardness of coating was found to be (430-1060 HV). The coating showed superior hot corrosion resistance as compared to boiler steel due to the formation of protective scale, Cr2O3. The protective scale formed at high temperature prevents hot corrosion of coated boiler steel as evident from the morphological studies made by using FE-SEM/EDS. The FeCrBSiMn alloy coating showed good adherence to the 310S substrate with negligible microspalling of the scales.