Corrosion Resistance of TiO2-ZrO2 Nanocomposite Thin Films Spin Coated on AISI 304 Stainless Steel in 3.5 wt. % NaCl Solution
Utilizing high chromium and nickel content in AISI 304 steel confers its good corrosion resistance. However, the high content of chromium and nickel increases the steel susceptibility to corrosion caused by the high concentration of chlorine. Consequently, the electrochemical and mechanical performance of the steel degrades. In this study, the effect of adding a layer containing a gelatin-dispersed mix of TiO2-ZrO2 nanoparticles on the corrosion rate and critical pitting potential of AISI 304 steel is studied. Two mix ratios of TiO2-ZrO2 nanoparticles to gelatin (0.5:0.5, 0.3:0.7) were used. Three different fractions of nanoparticles (1 wt. %, 2 wt. %, 3 wt. %) were used for each ratio. Potentiodynamic polarization examinations were used to measure the corrosion rate and the critical-pitting potential of the spin-coated AISI 304 steel in a simulated environment containing 3.5 wt. % NaCl. Scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) were used to study the morphology of the coated surfaces and the elemental composition of the nanocomposite coatings. The results show that the hybrid TiO2-ZrO2 nanoparticles coatings significantly improved the uniform and localized corrosion of the AISI 304 steel. Moreover, the results confirm the formation of homogeneous, stable, and crack-free coatings.