Enhancing the corrosion resistance of Q235 mild steel by incorporating poly (dopamine) modified h-BN nanosheets on zinc phosphate-silane coating

Phosphate-silane coatings were developed on the Q235 mild steel by incorporating poly(dopamine) modified h-BNs into the zinc phosphating bath to enhance the corrosion resistance. The effects of PDA modified h-BNs with varying concentrations (0.10-0.90 g/L) on the surface modification, and corrosion resistance of the composite coatings were investigated. Results show that denser and uniform coatings were achieved for samples containing poly(dopamine) modified h-BN. Sample 0.60 g/L attained outstanding corrosion resistance, which is in one order of magnitude lower than the pure coatings with a current density of 1.95 x 10(-5) A/cm(2). Modified h-BN effectively accelerates and enhances the corrosion resistance of the phosphate-silane coatings.