Steel surface treatment with three different acid solutions and its effect on the protective properties of the subsequent silane coating

Surface treatment of steel before application of silane coating plays important role to provide better corrosion protection. This work aims to evaluate the effect of steel surface treatment with acid solutions on the protective properties of subsequent organosilane coating. For this purpose, sulfuric, phosphoric and hydrochloric acid solutions were prepared at pH 3. The change in surface chemistry and morphology of mild steel surface after acid treatment was assessed by FE-SEM, XPS and water contact angle measurements. After surface treatment with acid solutions, a silane coating was applied on the steel samples. EIS measurements on the silane coated samples showed that the one treated by sulfuric acid solution provided better protection compared to the rest of samples.