KCl-Induced Corrosion of the FeCrAl Alloy Kanthal ® AF at 600 °C and the Effect of H2O

Abstract

The present study investigates the influence of H2O and KCl on the high-temperature corrosion of the FeCrAl alloy Kanthal® AF. Polished samples, with and without applied KCl, were exposed isothermally to O2 or O2 + H2O at 600 °C. The samples were investigated using TGA, XRD, SEM/EDX, AES and IC. It was found that KCl accelerates corrosion and that a rapidly growing iron, chromium-rich oxide forms in both environments. Chromate formation and alloy chlorination are shown to initiate the formation of non-protective oxide scales. In addition, aluminium nitrides form in the alloy substrate in both environments.