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 × 10−5 A/cm2. Modified h-BN effectively accelerates and enhances the corrosion resistance of the phosphate-silane coatings. •Modified boron nitride (h-BN) nanosheets were integrated into zinc phosphating bath.•Modified h-BN incorporation results in uniform and denser phosphate-silane coatings.•Modified h-BN acts as environmental friendly accelerator for zinc phosphating bath.•Corrosion resistance of modified h-BN-incorporated phosphate coatings is enhanced.