Microstructure and High-temperature Corrosion Behavior of Fe-Cr-B-C-Al Coating Prepared by High Velocity Arc Spraying

The Fe-Cr-B-C-Al coating was prepared on 20G steel substrate by high velocity arc spraying (HVAS) technology. The microstructure and mechanical properties of the coating were analyzed by optical microscope (OM), scanning election microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer (XRD), universal tensile testing machine and Vickers hardness tester. The high temperature corrosion test was done at 650 ℃ and compared with 20G steel to study the high-temperature corrosion resistance of the coating. The results show that the HVAS Fe-Cr-B-C-Al coating had the typical lamellar structure and combined well with the substrate. There were few oxides and pores in the coating. After corrosion at 650 ℃ for 100 h, the mass gain of the 20G steel was about 13 times of that of the coating. In the process of high-temperature corrosion, the protective oxide film was formed on the surface of the coating, which improved the high-temperature corrosion resistance of the coating.