Corrosion inhibition of mild steel in acidic medium by using green inhibitors

Abstract

The corrosion is a serious problem and it is defined as gradual destruction of materials by chemical or electrochemical reaction gradually. Mild steel is widely used for construction purpose in many industries due to its mechanical strength but corrosion degrades the useful properties of such type of materials and finally corroded it. To prevent the valuable resources, there is need to understand how these corrosion protection technologies can be applied so these technologies must preserve them. Presently, inhibitors are used commonly as the best method to inhibit corrosion of metal especially in acid. Many researchers had studied the corrosion of mild steel in acidic media by using many organic and inorganic compounds but, these compounds are toxic, costly and unsafe to environment. Research has shown that natural products found to have good inhibition efficiency and serve as most effective eco-friendly corrosion inhibitors. This made the researcher to focus on the use of natural products. In the present study, the inhibitive effect of Morus Rubra leaf extract, Dalbergia Sisso leaf extract and Sorghum Vulgare leaf extract on the corrosion of mild steel in acidic medium has been investigated through Galvanostatic polarization, Electrochemical impedence spectroscopy and surface analysis by SEM (Scanning Electron Microscopy) and AFM (Atomic Force Microscopy). Corrosion inhibition efficiency for all these green inhibitors rises with rise in plant extract concentration. The corrosion is inhibited by adsorption of MRLE, DBSLE and SVLE on the surface of mild steel followed by the Langmuir isotherm. Scanning electron microscopic studies and atomic force microscopic studies also investigate the change in surface topography by using these plants leaf extract. The result obtained through these studies shows that plants extract plays an important role in inhibiting corrosion process and serve as effective inhibitors for the corrosion of mild steel in sulphuric acid medium. Keywords: Corrosion, Mild Steel, Plants Leaf Extrac