Surface and corrosion properties of Type 430 ferritic stainless steel in parsley ( Petroselinum Sativum ) essential oil-containing sulphuric acid solution

Abstract This study examined the corrosion inhibiting properties of parsley ( petroselinum sativum ) essential oils, for Type 430 ferritic stainless steel in 0.5 molar sulphuric acid solutions. In this study, weight loss, electrochemical and scanning electron microscope techniques were used in gaining a detailed understanding of inhibition effects of parsley ( petroselinum sativum ) essential oils (PEO) on Type 430 ferritic stainless steel corrosion. The inhibitor studied exhibits good anti-corrosion performance with 98.65% inhibition efficiency. This result could be ascribed to the adsorbed PEO on the surface of the stainless steel, and this was verified by surface visualization using optical and scanning electron microscope techniques while the crystallographic variation of the inhibited sample is studied by x-ray diffraction (XRD). The adsorption of PEO onto stainless steel surface is controlled by Langmuir adsorption isotherms. Optical images of non-inhibited specimens showed a severely corroded surface with a visible macro pit on the stainless steel from sulphuric solutions. The inhibited sample shows improved surface owing to the surface protection effect of PEO molecules. The corrosion inhibition performance of PEO is due to the presence of active constituents which enhanced the film formation over the surface of the metal, thus, mitigating corrosion.