NaNi(H2PO3)3·H2O as a novel corrosion inhibitor for X70-steel in saline produced water

Abstract NaNi(H 2 PO 3 ) 3 ·H 2 O (NaNiPh) has been tested as a novel inhibitor for X70 steel corrosion in the saline produced water (SPW). The study was carried out using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Results revealed that NaNiPh exerts a protective effect against X70 steel corrosion in SPW; showing a maximum efficiency of 83.2% at a concentration of 100 ppm. Polarization curves showed that NaNiPh is a mixed-type inhibitor. Phenomenon of physical adsorption is proposed for the inhibition and the process followed the Freundlich adsorption isotherm. The activation energy as well as other thermodynamic parameters for the inhibition process was calculated and discussed.