Study on Fabrication and Corrosion Resistance of Ni-Based Alloy Coating on P110 Steel by Electro Spark Deposition

In this study, a Ni-based alloy coating has been fabricated on P110 oil casing tube steel (P110 steel) surface by electro spark deposition (ESD) process, aiming to improve the latter’s corrosion resistance and increase the life in operation. Scanning electron microscope (SEM), energy dispersive x-ray spectrometer (EDS), and x-ray diffraction (XRD) were used to investigate the surface morphology/composition, cross-sectional microstructure, and phase constitutions of the ESD coating. Electrochemical experiments, including open-circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were carried out in simulated oilfield brine and simulated stratum water to examine the anticorrosion property of the ESD coating. The results revealed that the ESD coating was continuous and compact and exhibited higher OCPs, charge transfer resistance, and lower corrosion current densities than the uncoated P110 steel in the selected corrosion media.