Electrochemical Corrosion Behavior of Fe Based Amorphous / Nanocrystalline Composite Coating Prepared by High Velocity Oxy-Fuel Thermal Spraying

Abstract Thermal spraying of corrosion resistant alloys onto low alloy steel substrates has received much attention as a method to protect against corrosion in seawater or corrosive solutions, such as mineral or organic acids. The need to ensure high coating quality with minimal porosity and cracking, and with low oxide levels is best achieved in metallic alloys using the high velocity oxyfuel (HVOF) spraying process. This article investigates the electrochemical corrosion behavior of HVOF sprayed coatings, covering coating preparation and characterization, immersion testing, and electrochemical testing. The discussion provides information on immersion test results, polarization plots for coatings, comparison of corrosion performance, influence of microstructure on corrosion performance, and comparison with bulk alloy materials. The results reported in this article have been selected to demonstrate the use of the cyclic potentiodynamic polarization method to rank the corrosion performance of HVOF sprayed Ni-alloy coatings.

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Electrochemical Corrosion Behavior of Ni-Fe-Co-P Alloy Coating Containing Nano-CeO2 Particles in NaCl Solution

Materials ◽

10.3390/ma12162614 ◽

2019 ◽

Vol 12 (16) ◽

pp. 2614 ◽

Cited By ~ 4

Author(s):

Xiuqing Fu ◽

Wenke Ma ◽

Shuanglu Duan ◽

Qingqing Wang ◽

Jinran Lin

Keyword(s):

Composite Coating ◽

Corrosion Behavior ◽

Electrochemical Impedance ◽

Electrochemical Corrosion ◽

Alloy Coating ◽

Charge Transfer Resistance ◽

Corrosion Mechanism ◽

Nacl Solution ◽

Transfer Resistance ◽

Electrochemical Corrosion Behavior

In order to study the effect of nano-CeO2 particles doping on the electrochemical corrosion behavior of pure Ni-Fe-Co-P alloy coating, Ni-Fe-Co-P-CeO2 composite coating is prepared on the surface of 45 steel by scanning electrodeposition. The morphology, composition, and phase structure of the composite coating are analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of the coatings with different concentrations of nano-CeO2 particles in 50 g/L NaCl solution is studied by Tafel polarization curve and electrochemical impedance spectroscopy. The corrosion mechanism is discussed. The experimental results show that the obtained Ni-Fe-Co-P-CeO2 composite coating is amorphous, and the addition of nano-CeO2 particles increases the mass fraction of P. With the increase of the concentration of nano-CeO2 particles in the plating solution, the surface flatness of the coating increases. The surface of Ni-Fe-Co-P-1 g/L CeO2 composite coating is uniform and dense, and its self-corrosion potential is the most positive; the corrosion current and corrosion rate are the smallest, and the charge transfer resistance is the largest, showing the best corrosion resistance.

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