High temperature corrosion and electrochemical behavior of INCONEL 625 weld overlay in PbSO4-Pb3O4-PbCl2-CdO-ZnO molten salt medium

Molten salt-induced corrosion, electrochemical behavior, and degradation mechanisms of the alloy Inconel 625 weld overlay, deposited on the surface of the carbon steel through an automatic gas metal arc welding (GMAW) process, were investigated. OCP, EIS, potentiodynamic polarization, weight-loss measurement, SEM/EDX, XRD, DTA, and ICP/AAS techniques were utilized to study the electrochemical and corrosion behavior of the weld overlay alloy 625 exposed to a molten salt medium containing 47 PbSO4-23 ZnO-13 Pb3O4-10 CdO-7 PbCl2 (wt.%) at 600, 700, and 800 °C for 24 h. EIS data fit well into an equivalent circuit representing a two porous/non-protective scales model.