No abstract

No abstract

Inconel 718 is one of the most commonly used nickel‐based superalloy materials in petroleum industry due to its high temperature mechanical properties and corrosion resistance. Generally, corrosion resistance assessment of materials at high temperature condition is a challenging task and most of the previous studies in this area were based on estimation of weight‐loss in the sample, which cannot provide accurate results, and it could be very time‐consuming. In this study, a high temperature corrosion measurement device (HTCMD) was used to evaluate electrochemical behavior of HVOF deposited Inconel 718 coating in 3.5 wt% NaCl solution at elevated temperatures. EIS and potentiodynamic polarization results revealed very low corrosion rate of the Inconel 718 coating. Materials characterization by SEM, XRD, and EDS indicated formation of chromium oxide rich unstable passive layer resulted in localized protection of superalloy material that was not sufficient to provide corrosion protection for the entire surface, during the service at high temperature condition.