Extract of Angelica sinensis as oilfield corrosion inhibitor for mild steel in H2SO4 media

The root extract of Angelica sinensis (AS) was examined as potential corrosion inhibitor of mild steel in 1 M sulphuric acid (H2SO4) media using weight loss, electrochemical and surface studies. Angelica sinensis has its medicinal importance in Chinese traditional medicine since ancient time. It is used to cure several diseases and most important one includes the anemia in women. So, this medicinal herb is chosen as naturally friendly corrosion inhibitor for mild steel in sulphuric acid, as it is easily available, cheap and easy to use. The weight loss results discovered that samples covered with AS showed less weight loss compared to the samples without AS. The electrochemical tests including electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) showed good mitigation efficiency of AS in 1 M H2SO4 media. The mixed shift of the anodic and cathodic slopes advised that the AS represented as mixed category. The surface studies were completed using scanning electron microscopy (SEM) and contact angle. Both the studies displayed even surface in existence of AS and rough surface in its absence. The kinetic and thermodynamic parameters were also calculated. All the experimental results are in decent pact respectively.