A Study of the Corrosion Resistance of Thermal Sprayed Stainless Steel Coatings for Reinforcing Bars

Abstract

The potential for using stainless steel coatings to protect steel reinforcing bars from corrosion especially in a salt contaminated concrete environment was evaluated. Type 304, 316 and 420 stainless steel coated coupons and reinforcing bars were prepared using the Twin-Wire Electric Arc (TWEA) and High Pressure/High Velocity Oxygen-Fuel (HP/HVOF) processes. Metallographic examinations were conducted to determine the coating density and the oxide content. The corrosion resistance of the coatings was evaluated using linear polarization and salt spray techniques. The oxide content of the coating in the TWEA process can be significantly reduced using argon or nitrogen as primary and arc jet gases. This did not have a significant effect on porosity of the coating.