Polarization resistance of stainless steel-coated rebars

Stainless steel (316L) coated coupons and rebars were prepared using the twin-wire electric arc (TWEA) and high pressure/high velocity oxygen-fuel (HP/HVOF) processes. Metallographic examination was performed to characterize the coating density and the oxide content. The corrosion performance of the coatings was evaluated using linear polarization, AC impedance, and salt spray techniques. It appears that the coating prepared using the HP/HVOF process is far superior in terms of polarization resistance performance than that prepared using the TWEA process. The former process produces a dense, low-oxide-content coating while the latter produces relatively porous coatings.