Anti-corrosive properties of two epoxy primer systems applied to steel surfaces prepared with various mechanical abrasive treatments

The present study evaluates an anticorrosive system of epoxy primers applied on carbon steel coupons under different surface preparation techniques: dry abrasive blasting up to Sa 21/2, wet abrasive blasting up to Sa 21/2 and mechanical treatment up to SSPC SP-11. The epoxy primers were pigmented with zinc phosphate, commonly used in offshore structures, on which intermediary and anti-scaling paints are applied. The components of this primers system were analyzed through Fourier transform infrared spectroscopy (FTIR) while the corrosion protection was analyzed by electrochemical impedance spectroscopy (EIS) and potential monitoring, as well as the adhesion to the coupons' surface immersed in 3.5%(w/v) NaCl solution (3.5 g of NaCl in 100 mL of solution). The results showed a better epoxy system adhesion to coupons surface prepared by dry abrasive blasting to Sa 21/2. According to the electrochemical results, better corrosion protection was observed in samples prepared by wet abrasive blasting up to Sa 21/2.