Corrosion behavior of the Fe-MnCr-Si alloys deposited by ASP and HVOF thermal spraying process

The manufacture and repairs of components that exhibit cavitation loss is one issue of the manufacturing and maintenance industries. The cavitation often occurs in hydraulic turbine rotors, radial pump blades, valves, etc. In addition to cavitation, corrosion can occur, which is basically the degradation of a material due to chemical or electrochemical reactions. The intensity of corrosion is dependent on the composition and concentration of the corrosive environment and the corrosion resistance of the alloy. In this paper, the corrosion behavior of the ASP and HVOF coatings were evaluated. The corrosion behavior of the coatings was studied by open circuit potencial, potentiodynamic polarization and electrochemical impedance spectroscopy. The coatings, based on austenitic stainless steel, promoted galvanic protection to the carbon steel substrate, ASP and HVOF coatings showed different corrosion behavior mainly caused by their different morphologies and porosity.