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.
Wear and corrosion performance of metallurgical coatings in sodium
