Spraying of Fe-based amorphous coating with high corrosion resistance by HVAF

Fe-based amorphous coating with composition of Fe42.87Cr15.98Mo16.33C15.94B8.88 has been deposited on a mild steel substrate by high velocity air fuel thermal spraying. The microstructure and corrosion properties of the Fe-based alloy coating were studied in detail. It was found that the obtained Fe-based coating showed fully amorphous state with about 100 μm in thickness. Also, the obtained coating exhibited very dense structure with a porosity of 1.5%. Polarization tests demonstrated that the coating exhibited better corrosion resistance than stainless steel in NaOH solution and simulated seawater. The reasons of superior corrosion have been discussed from the alloy elements and the homogeneous structure of Fe-based amorphous coating.