Effects of temperature and water vapour on Cr-species volatilisation, oxidation and scale adhesion of a Type 409L stainless steel for application as interconnect of low temperature solid oxide fuel cells

Abstract

Though the classical transport theory does not mathematically express the Arrhenius-like relation between Cr-loss flux due to volatilisation and absolute temperature, such relation was experimentally observed for 409L stainless steel exposed at 600–750 °C. Volatilisation calculation in the present cases can be estimated giving such relation because of the nearly linear relation between mass transfer coefficient and temperature. Cr-loss fluxes in O2 with 20 and 40 % H2O are close to or coincided with the fluxes calculated from MnCr2O4 evaporation. Increasing water vapour could enhance volatilisation contributed from the raised CrO2(OH)2 pressure, reduce oxidation rate, and worsen scale adhesion.