Experimental system for electrochemical corrosion studies in high temperature aqueous solutions

A new experimental high temperature electrochemical system was designed for measuring electrochemical corrosion rates in high temperture dilute electrolyte solutions. The system was tested at temperatures up to 360°C and pressures up to 26 MPa. The ion concentrations in the aqueous boiler solutions are typically low, which makes corrosion rates difficult to quantify using the traditional mass loss and metallography techniques. The newly designed electrochemical system with annular-duct flow-through working-counter electrode assembly was proved to be efficient for in-situ corrosion studies. The DC polarization and electrochemical impedance spectroscopy (EIS) methods were found most applicable techniques to measure the corrosion current in the high temperature/low density subcritical environments.