材料期刊网

FeCrMoMnWBCSi amorphous metallic coatings (AMCs) were deposited onto the 304 stainless steel (base material of pump impeller operated in sand-containing seawater) by high-velocity oxygen-fuel (HVOF) thermal spray. The preparation, microstructural characteristics, and static corrosion behavior of the AMCs were presented. The microstructure and corrosion behavior of the AMCs were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and electrochemical methods. Melt-spun ribbon and 304 stainless steel were also used for comparison purposes. The results indicated that the AMCs can spontaneously passivate with a wide passive region, and much higher ability to withstand pitting corrosion than that of the 304 stainless steel for the high pitting resistance equivalent value. The passive current density of the AMCs was at least two orders of magnitude higher than the counterpart ribbon, which showed a slightly decreased uniform corrosion resistance of the AMCs due to the incompact structure and porosity. The corrosion resistance of the AMCs increased with the coating thickness and decreased with the concentration of NaCl solution. A stable passivation ability held in the AMCs endowed them suitably used in marine environments.