Application of Liquid Solution Models for the Prediction of Corrosion Phenomena in the Na–K Melt

Abstract

With the mathematical tool of pseudo-regular solutions, we calculated the solubility of Fe, Cr, Ni, V, Mn, and Mo in eutectic Na–K melt and compared the calculation results with the available experimental data in the literature on the mass transfer of austenitic chrome-nickel steel components in a sodium-potassium loop in nonisothermal conditions. We show that the Wagner parameters of the interaction between oxygen and transition metal might be applied to predict the corrosion behavior of the construction materials in sodium-potassium melt under the presence of oxygen impurity. We present the calculation results of the threshold oxygen concentration required to form ternary sodium oxides with transition metals (Fe, Cr, Ni, V, Mn, Mo) in conditions in which the pure metal is in contact with eutectic Na–K melt.