Corrosion resistance of HastelloyC coatings formed by an improved HVOF thermal spraying process

Abstract

The corrosion resistance of coatings obtained by an improved HVOF spraying method was evaluated by various electrochemical techniques. This spraying system could increase the flight velocity of sprayed particles and suppress their oxidation simultaneously by attachment of a gas shroud, employing nitrogen gas at a large flow rate. The process brought about attainment of both smaller porosity and lower oxide content of the resulting coatings. Consequently, the resistance of HVOF sprayed coatings against seawater corrosion was improved considerably.