Abstract
The current study is conducted to develop an optimized corrosion resistant method. Low carbon steel (A-36) is used with five different coatings along with an uncoated s ample, to characterize the behavior against corrosion. Specimens are coated with red oxide primer, oil paint, and oil paint-primer. Coatings are also made by mixing nanoparticles of titanium oxide (TiO2) and zinc oxide (ZnO) with oil paint. One molar nitric acid (HNO3) solution is used to produce acidic medium, one molar sodium hydro-oxide (NaOH) solution is used to make basic medium and distilled water is used as a neutral medium. The linear polarization resistance (LPR) technique is used to determine the corrosion rate of different coatings in all conditions. In the acidic environment, the bare sample gives maximum corrosion of 191.5 mpy. The corrosion rate is decreased when coated with primer and paint respectively. But the minimum value of 0.302 mpy is observed in zinc oxide nanoparticles based coatings. In basic medium corrosion rate is observed to be low in bare and all types of coatings compared to the acidic environment. It shows that mild steel produces less metal oxides in a basic environment. The corrosion rate trend in the basic medium is the same having maximum in the bare sample (i.e. 0.1044 mpy) while minimum in zinc oxide-based coating (i.e. 0.000261). In distilled water, the bare sample gives maximum corrosion rate of 12.98 mpy as expected. Comparing three environments, acidic medium gives the highest corrosion rate in bare samples and in all coatings. Hence proper attention should be given when mild steel is being used in an acidic environment. The maximum corrosion rate is observed in bare samples while minimum in specimen coated with zinc oxide-based coatings. Hence it can be concluded that for better corrosion resistance, a coating made by mixing paint with zinc oxide nanoparticles should be used that works in all environments. Current study can be considered as easy to use solution for corrosion prevention in different corrosive environments.