Corrosion behavior for Alloy 690 and Alloy 800 tubes in simulated primary water

Corrosion behavior for Alloy 690 and Alloy 800 in simulated primary water is studied by open-circuit potential (OCP) measurement, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Rise of pressure and temperature lead to negative shift of corrosion potential for both Alloy 690 and Alloy 800. EIS results show that the effect of pressure on corrosion only exists in low-frequency region, while the effect of temperature presents at the entire frequency range. Alloy 690 shows a better corrosion resistance than Alloy 800 at present investigated conditions.

► Alloy 690 shows better corrosion resistance than Alloy 800.
► Effect of pressure mainly presents at low frequency of EIS.
► Influence of temperature shows in the entire frequency region.
► The influence of temperature is greater than pressure.