Rapid Evaluation of Corrosion Resistance of Ni-Base Alloys in Molten Salts Using AC Impedance Method

Abstract

Corrosion performance of eighteen commercial and thirteen lab-melted alloys have been evaluated in three different molten salts, Na₂SO₄–K₂SO₄–ZnSO₄, NaCl–KCl–LiCl–CaCl₂ and NaCl–KCl–Na₂SO₄–K₂SO₄–ZnSO₄, in the temperature range of 723 to 873 K. The evaluation was performed using an AC impedance screening test, which was developed in previous study as an instrument for rapid evaluation of molten salt corrosion. The obtained impedance data has been statistically analyzed by a multiple linear regression method and the effect of alloy elements on the corrosion performance in these molten salts has been clarified.